From 10a9a2e86db118cd4b638de5aaeb5fa1243f74fe Mon Sep 17 00:00:00 2001
From: Marko Ristin-Kaufmann <marko@ristin.ch>
Date: Thu, 15 Oct 2026 19:00:22 +0200
Subject: [PATCH] Make read-only sequences of verifications generic

We make the read-only ``Sequence[...]`` arguments of the verification
functions generic if their items are instances of a class with
descendants. This way, the sequences of the descendants can be passed
without a copy, as aas-core-meta V3.2 does, *e.g.*, in
``ID_shorts_are_unique(self.submodel_elements)``.

Go declares a type parameter, *e.g.*, ``func IDShortsAreUnique[
ReferablesT ourtypes.IReferable](referables []ReferablesT)``, C++
a template defined in the header, C# the covariant
``IReadOnlyList<T>``, and Java the wildcard ``List<? extends T>``.
Python and TypeScript accept the sequences of the descendants already.

The methods stay invariant, since Go methods can not have type
parameters and C++ virtual methods can not be templates, and so do
the mutable ``List[...]`` arguments. The type inference now checks
the items of all the list arguments, and restricts the usages of
the generic sequences, *e.g.*, they can not be passed to a method.

We support ``in`` on the generic sequences with the new
``ourcommon.SliceContainsInstance`` in Go, and the immutable aliases,
*e.g.*, ``alias: Final[Sequence[Item]] = items``, which C# and Java
now declare with ``var``.

We test all this in the new common meta-model
``variance_of_containers``.
---
 .../cpp/lib/_generate_verification.py         |   730 +-
 aas_core_codegen/cpp/transpilation.py         |   159 +-
 .../csharp/lib/_generate_verification.py      |    48 +-
 aas_core_codegen/csharp/transpilation.py      |    13 +
 .../golang/lib/_generate_common.py            |    18 +
 .../golang/lib/_generate_verification.py      |   105 +-
 aas_core_codegen/golang/transpilation.py      |   102 +-
 aas_core_codegen/intermediate/__init__.py     |     1 +
 aas_core_codegen/intermediate/_types.py       |    45 +
 .../intermediate/type_inference.py            |   266 +-
 .../java/lib/_generate_verification.py        |    49 +-
 aas_core_codegen/java/transpilation.py        |    14 +
 .../variance_of_containers.py                 |   407 +
 .../expected_symbol_table.txt                 |  1637 ++
 .../include/dummy/verification.hpp            |    73 +-
 .../expected_output/src/verification.cpp      |    36 -
 .../include/dummy/verification.hpp            |   108 +-
 .../expected_output/src/verification.cpp      |    57 -
 .../include/dummy/verification.hpp            |    41 +-
 .../expected_output/src/verification.cpp      |    18 -
 .../expected_output/include/dummy/common.hpp  | 10196 +++++++++++
 .../include/dummy/constants.hpp               |    38 +
 .../include/dummy/enhancing.hpp               |  1104 ++
 .../include/dummy/iteration.hpp               |   372 +
 .../include/dummy/jsonization.hpp             |   272 +
 .../expected_output/include/dummy/pattern.hpp |    34 +
 .../expected_output/include/dummy/revm.hpp    |   213 +
 .../include/dummy/stringification.hpp         |    91 +
 .../expected_output/include/dummy/types.hpp   |   512 +
 .../include/dummy/verification.hpp            |   884 +
 .../include/dummy/visitation.hpp              |   103 +
 .../include/dummy/wstringification.hpp        |    63 +
 .../include/dummy/xml_path.hpp                |   136 +
 .../include/dummy/xmlization.hpp              |   245 +
 .../expected_output/src/common.cpp            | 14232 ++++++++++++++++
 .../expected_output/src/constants.cpp         |    25 +
 .../expected_output/src/iteration.cpp         |   951 ++
 .../expected_output/src/jsonization.cpp       |  2917 ++++
 .../expected_output/src/pattern.cpp           |    15 +
 .../expected_output/src/revm.cpp              |   861 +
 .../expected_output/src/stringification.cpp   |   375 +
 .../expected_output/src/types.cpp             |   375 +
 .../expected_output/src/verification.cpp      |  1246 ++
 .../expected_output/src/visitation.cpp        |   186 +
 .../expected_output/src/wstringification.cpp  |    94 +
 .../expected_output/src/xml_common.cpp        |  1624 ++
 .../expected_output/src/xml_common.hpp        |   676 +
 .../expected_output/src/xml_path.cpp          |   239 +
 .../expected_output/src/xmlization.cpp        |  3185 ++++
 .../expected_output/stdout.txt                |     1 +
 .../expected_output/test/catch_main.cpp       |    12 +
 .../expected_output/test/common.cpp           |   422 +
 .../expected_output/test/common.hpp           |   142 +
 .../expected_output/test/common_examples.cpp  |   335 +
 .../expected_output/test/common_examples.hpp  |    88 +
 .../test/common_jsonization.cpp               |    93 +
 .../test/common_jsonization.hpp               |    42 +
 .../test/common_xmlization.cpp                |   637 +
 .../test/common_xmlization.hpp                |    50 +
 .../test/test_descent_and_descent_once.cpp    |   264 +
 .../test/test_jsonization_dispatch.cpp        |   125 +
 .../test_jsonization_of_concrete_classes.cpp  |   467 +
 .../expected_output/test/test_revm.cpp        |   286 +
 .../test/test_string_helpers.cpp              |   349 +
 .../test/test_stringification_base64.cpp      |   337 +
 .../test/test_stringification_of_enums.cpp    |    84 +
 .../test/test_verification.cpp                |   324 +
 .../test/test_wstringification_of_enums.cpp   |    84 +
 .../test/test_x_or_default.cpp                |    24 +
 .../test/test_xmlization_dispatch.cpp         |   149 +
 .../test_xmlization_of_concrete_classes.cpp   |   349 +
 .../input/snippets/namespace.txt              |     1 +
 .../expected_output/return_code.json          |     1 +
 .../expected_output/stderr.txt                |     2 +
 .../expected_output/stdout.txt                |     0
 .../input/snippets/namespace.txt              |     1 +
 .../meta_model.py                             |    50 +
 .../expected_output/dummy/verification.cs     |    18 +-
 .../expected_output/dummy/verification.cs     |    15 +-
 .../expected_output/dummy/verification.cs     |     7 +-
 .../expected_output/dummy.Tests/Common.cs     |   156 +
 .../expected_output/dummy.Tests/CommonJson.cs |   222 +
 .../dummy.Tests/CommonJsonization.cs          |   158 +
 .../dummy.Tests/TestCopying.cs                |   335 +
 .../TestDescendAndVisitorThrough.cs           |   201 +
 .../dummy.Tests/TestDescendOnce.cs            |   125 +
 .../dummy.Tests/TestEnhancing.cs              |   168 +
 .../TestJsonizationOfConcreteClasses.cs       |   798 +
 .../dummy.Tests/TestJsonizationOfEnums.cs     |    23 +
 .../TestJsonizationOfInterfaces.cs            |   135 +
 .../dummy.Tests/TestOverXOrEmpty.cs           |    40 +
 .../dummy.Tests/TestStringHelpers.cs          |   411 +
 .../dummy.Tests/TestVerificationOfEnums.cs    |    22 +
 .../dummy.Tests/TestXOrDefault.cs             |    72 +
 .../dummy.Tests/TestXmlizationErrors.cs       |   156 +
 .../TestXmlizationOfConcreteClasses.cs        |   703 +
 .../dummy.Tests/TestXmlizationOfInterfaces.cs |   251 +
 .../expected_output/dummy/common.cs           |   199 +
 .../expected_output/dummy/constants.cs        |    22 +
 .../expected_output/dummy/copying.cs          |   178 +
 .../expected_output/dummy/enhancing.cs        |   565 +
 .../expected_output/dummy/jsonization.cs      |  1287 ++
 .../expected_output/dummy/reporting.cs        |   275 +
 .../expected_output/dummy/stringification.cs  |    22 +
 .../expected_output/dummy/types.cs            |   578 +
 .../expected_output/dummy/verification.cs     |   725 +
 .../expected_output/dummy/visitation.cs       |   311 +
 .../expected_output/dummy/xmlcommon.cs        |   319 +
 .../expected_output/dummy/xmlization.cs       |  1599 ++
 .../expected_output/stdout.txt                |     1 +
 .../input/snippets/namespace.txt              |     1 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../verification/verification.go              |    14 +-
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../enum/expected_output/common/common.go     |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../verification/verification.go              |    24 +-
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../verification/verification.go              |    12 +-
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../sets/expected_output/common/common.go     |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../expected_output/common/common.go          |    16 +
 .../tuples/expected_output/common/common.go   |    16 +
 .../unions/expected_output/common/common.go   |    16 +
 .../expected_output/common/common.go          |   350 +
 .../string_helpers_test.go                    |   347 +
 .../expected_output/constants/constants.go    |    11 +
 .../expected_output/enhancing/enhancing.go    |   478 +
 .../enhancing/test/enhancing_test.go          |   295 +
 .../internal/xmlcommon/xmlcommon.go           |  1062 ++
 .../jsonization/jsonization.go                |  1156 ++
 .../test/classes_with_descendants_test.go     |   130 +
 .../jsonization/test/common_test.go           |   189 +
 .../jsonization/test/concrete_classes_test.go |   521 +
 .../jsonization/test/enums_test.go            |    11 +
 .../ourtesting/common_jsonization.go          |   350 +
 .../expected_output/ourtesting/constants.go   |    43 +
 .../expected_output/ourtesting/deep_equal.go  |   239 +
 .../expected_output/ourtesting/doc.go         |     6 +
 .../expected_output/ourtesting/filesystem.go  |    69 +
 .../expected_output/ourtesting/tracing.go     |    20 +
 .../expected_output/reporting/reporting.go    |   240 +
 .../expected_output/stdout.txt                |     1 +
 .../stringification/stringification.go        |    74 +
 .../types/descend_test/common.go              |    96 +
 .../types/descend_test/descend_once_test.go   |   109 +
 .../types/descend_test/descend_test.go        |   109 +
 .../types/is_xxx_test/is_xxx_test.go          |   157 +
 .../expected_output/types/types.go            |   704 +
 .../xxx_or_default_test.go                    |   153 +
 .../verification/test/verification_test.go    |   692 +
 .../verification/verification.go              |   863 +
 .../xmlization/test/common_test.go            |   296 +
 .../xmlization/test/concrete_classes_test.go  |   582 +
 .../expected_output/xmlization/xmlization.go  |  1221 ++
 .../input/snippets/repo_url.txt               |     1 +
 .../expected_output/common/common.go          |    16 +
 .../java/dummy/verification/Verification.java |    16 +-
 .../java/dummy/verification/Verification.java |    12 +-
 .../java/dummy/verification/Verification.java |     4 +-
 .../main/java/dummy/common/StringHelpers.java |   142 +
 .../src/main/java/dummy/common/Tuple1.java    |    23 +
 .../src/main/java/dummy/common/Tuple2.java    |    23 +
 .../src/main/java/dummy/common/Tuple3.java    |    23 +
 .../src/main/java/dummy/common/Tuple4.java    |    23 +
 .../src/main/java/dummy/common/Tuple5.java    |    23 +
 .../src/main/java/dummy/common/Tuple6.java    |    23 +
 .../src/main/java/dummy/common/Tuple7.java    |    23 +
 .../src/main/java/dummy/common/Tuple8.java    |    23 +
 .../main/java/dummy/constants/Constants.java  |    37 +
 .../src/main/java/dummy/copying/Copying.java  |   175 +
 .../main/java/dummy/enhancing/Enhanced.java   |    23 +
 .../dummy/enhancing/EnhancedContainer.java    |   110 +
 .../dummy/enhancing/EnhancedSomeItem.java     |    87 +
 .../dummy/enhancing/EnhancedSpecialItem.java  |    97 +
 .../java/dummy/enhancing/EnhancedWrapper.java |    77 +
 .../main/java/dummy/enhancing/Enhancer.java   |    64 +
 .../main/java/dummy/enhancing/Unwrapper.java  |    56 +
 .../main/java/dummy/enhancing/_Wrapper.java   |   162 +
 .../dummy/generation/ContainerBuilder.java    |    43 +
 .../dummy/generation/SomeItemBuilder.java     |    35 +
 .../dummy/generation/SpecialItemBuilder.java  |    43 +
 .../java/dummy/jsonization/Jsonization.java   |  1050 ++
 .../main/java/dummy/reporting/Reporting.java  |   345 +
 .../stringification/Stringification.java      |    22 +
 .../main/java/dummy/types/enums/IEnum.java    |    24 +
 .../main/java/dummy/types/impl/Container.java |   261 +
 .../main/java/dummy/types/impl/Descent.java   |    84 +
 .../main/java/dummy/types/impl/SomeItem.java  |   120 +
 .../java/dummy/types/impl/SpecialItem.java    |   146 +
 .../main/java/dummy/types/impl/Wrapper.java   |   176 +
 .../main/java/dummy/types/model/IClass.java   |    61 +
 .../java/dummy/types/model/IContainer.java    |    47 +
 .../main/java/dummy/types/model/IItem.java    |    29 +
 .../java/dummy/types/model/ISomeItem.java     |    22 +
 .../java/dummy/types/model/ISpecialItem.java  |    25 +
 .../main/java/dummy/types/model/IWrapper.java |    25 +
 .../java/dummy/verification/Verification.java |   709 +
 .../dummy/visitation/AbstractTransformer.java |    44 +
 .../AbstractTransformerWithContext.java       |    54 +
 .../dummy/visitation/AbstractVisitor.java     |    37 +
 .../AbstractVisitorWithContext.java           |    45 +
 .../java/dummy/visitation/ITransformer.java   |    39 +
 .../visitation/ITransformerWithContext.java   |    44 +
 .../main/java/dummy/visitation/IVisitor.java  |    37 +
 .../dummy/visitation/IVisitorWithContext.java |    43 +
 .../java/dummy/visitation/VisitorThrough.java |    63 +
 .../main/java/dummy/xmlcommon/XmlCommon.java  |   586 +
 .../java/dummy/xmlization/Xmlization.java     |  1255 ++
 .../expected_output/src/test/java/Common.java |   150 +
 .../src/test/java/CommonJson.java             |    98 +
 .../src/test/java/CommonJsonization.java      |   129 +
 .../src/test/java/TestCopying.java            |   265 +
 .../java/TestDescendAndVisitorThrough.java    |   166 +
 .../src/test/java/TestDescendOnce.java        |   105 +
 .../src/test/java/TestEnhancing.java          |   169 +
 .../TestJsonizationOfConcreteClasses.java     |   527 +
 .../src/test/java/TestJsonizationOfEnums.java |    25 +
 .../java/TestJsonizationOfInterfaces.java     |    91 +
 .../src/test/java/TestOverXOrEmpty.java       |    37 +
 .../src/test/java/TestStringHelpers.java      |   364 +
 .../test/java/TestVerificationOfEnums.java    |    26 +
 .../src/test/java/TestXOrDefault.java         |    53 +
 .../java/TestXmlizationOfConcreteClasses.java |   647 +
 .../test/java/TestXmlizationOfInterfaces.java |   154 +
 .../expected_output/stdout.txt                |     1 +
 .../input/snippets/package.txt                |     1 +
 .../expected_output/schema.json               |   133 +
 .../expected_output/stdout.txt                |     1 +
 .../input/snippets/schema_base.json           |    10 +
 .../expected_output/dev/tests/common.py       |   138 +
 .../dev/tests/common_jsonization.py           |   197 +
 .../dev/tests/common_xmlization.py            |   186 +
 .../test_descend_and_pass_through_visitor.py  |   112 +
 .../dev/tests/test_descend_once.py            |    49 +
 .../dev/tests/test_for_over_X_or_empty.py     |    64 +
 .../dev/tests/test_for_x_or_default.py        |    27 +
 ...jsonization_of_classes_with_descendants.py |    86 +
 .../test_jsonization_of_concrete_classes.py   |   166 +
 .../dev/tests/test_jsonization_of_enums.py    |    26 +
 .../dev/tests/test_len_slicing_and_find.py    |   310 +
 .../dev/tests/test_verification.py            |   295 +
 ..._xmlization_of_classes_with_descendants.py |   133 +
 .../test_xmlization_of_concrete_classes.py    |   314 +
 .../expected_output/dummy/common.py           |    87 +
 .../expected_output/dummy/constants.py        |    17 +
 .../expected_output/dummy/jsonization.py      |  1034 ++
 .../expected_output/dummy/reporting.py        |   191 +
 .../expected_output/dummy/stringification.py  |    17 +
 .../expected_output/dummy/types.py            |   905 +
 .../expected_output/dummy/verification.py     |   617 +
 .../expected_output/dummy/xmlcommon.py        |   759 +
 .../expected_output/dummy/xmlization.py       |  2476 +++
 .../expected_output/stdout.txt                |     1 +
 .../input/snippets/qualified_module_name.txt  |     1 +
 .../expected_output/src/common.ts             |   604 +
 .../expected_output/src/constants.ts          |    15 +
 .../expected_output/src/index.ts              |    23 +
 .../expected_output/src/jsonization.ts        |  1459 ++
 .../expected_output/src/stringification.ts    |    88 +
 .../expected_output/src/types.ts              |  1448 ++
 .../expected_output/src/verification.ts       |   818 +
 .../expected_output/src/xmlcommon.ts          |  1045 ++
 .../expected_output/src/xmlization.ts         |  1274 ++
 .../expected_output/stdout.txt                |     1 +
 .../test/common.base64.spec.ts                |   212 +
 .../test/common.base64url.spec.ts             |   145 +
 .../test/common.stringHelpers.spec.ts         |   205 +
 .../expected_output/test/common.ts            |   380 +
 .../expected_output/test/commonJsonization.ts |   272 +
 .../expected_output/test/commonXmlization.ts  |   273 +
 .../test/jsonization.common.spec.ts           |    31 +
 .../test/jsonization.concreteClasses.spec.ts  |   764 +
 .../test/jsonization.enums.spec.ts            |    12 +
 .../test/jsonization.interfaces.spec.ts       |   155 +
 .../test/jsonization.negative.spec.ts         |    77 +
 .../test/stringification.enums.spec.ts        |    12 +
 .../expected_output/test/types.casts.spec.ts  |   172 +
 ...types.descendAndPassThroughVisitor.spec.ts |   178 +
 .../test/types.descendOnce.spec.ts            |   115 +
 .../test/types.modelType.spec.ts              |   148 +
 .../test/types.overEnum.spec.ts               |    11 +
 .../test/types.overXOrEmpty.spec.ts           |    37 +
 .../test/types.typeMatches.spec.ts            |   140 +
 .../test/types.xOrDefault.spec.ts             |    88 +
 .../expected_output/test/verification.spec.ts |    49 +
 .../test/xmlization.basic.spec.ts             |    68 +
 .../test/xmlization.common.spec.ts            |    31 +
 .../test/xmlization.concreteClasses.spec.ts   |   306 +
 .../test/xmlization.enums.spec.ts             |    14 +
 .../test/xmlization.interfaces.spec.ts        |   166 +
 .../test/xmlization.negative.spec.ts          |   133 +
 .../input/snippets/package_documentation.txt  |     1 +
 .../input/snippets/package_identifier.txt     |     1 +
 .../expected_output/schema.xsd                |    88 +
 .../expected_output/stdout.txt                |     1 +
 .../input/snippets/root_element.xml           |     8 +
 .../expected_symbol_table.txt                 |  2252 +++
 dev/tests/intermediate/test_type_inference.py |   360 +-
 dev/tests/test_main.py                        |    54 +
 327 files changed, 102626 insertions(+), 469 deletions(-)
 create mode 100644 dev/test_data/common_meta_models/variance_of_containers.py
 create mode 100644 dev/test_data/intermediate/common_meta_models/variance_of_containers/expected_symbol_table.txt
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/common.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/constants.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/enhancing.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/iteration.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/jsonization.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/pattern.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/revm.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/stringification.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/types.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/verification.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/visitation.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/wstringification.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xml_path.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xmlization.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/common.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/constants.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/iteration.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/jsonization.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/pattern.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/revm.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/stringification.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/types.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/verification.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/visitation.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/wstringification.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.hpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_path.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xmlization.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/stdout.txt
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/catch_main.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.cpp
 create mode 100644 dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.hpp
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 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.common.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.concreteClasses.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.enums.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.interfaces.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.negative.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/stringification.enums.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.casts.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendAndPassThroughVisitor.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendOnce.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.modelType.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overEnum.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overXOrEmpty.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.typeMatches.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.xOrDefault.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/verification.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.basic.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.common.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.concreteClasses.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.enums.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.interfaces.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.negative.spec.ts
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_documentation.txt
 create mode 100644 dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_identifier.txt
 create mode 100644 dev/test_data/main/xsd/expected/variance_of_containers/expected_output/schema.xsd
 create mode 100644 dev/test_data/main/xsd/expected/variance_of_containers/expected_output/stdout.txt
 create mode 100644 dev/test_data/main/xsd/expected/variance_of_containers/input/snippets/root_element.xml
 create mode 100644 dev/test_data/parse/common_meta_models/variance_of_containers/expected_symbol_table.txt

diff --git a/aas_core_codegen/cpp/lib/_generate_verification.py b/aas_core_codegen/cpp/lib/_generate_verification.py
index c4162e149..df7af7b7b 100644
--- a/aas_core_codegen/cpp/lib/_generate_verification.py
+++ b/aas_core_codegen/cpp/lib/_generate_verification.py
@@ -11,6 +11,7 @@
     Mapping,
     Set,
     Final,
+    Dict,
 )
 
 from icontract import ensure, require
@@ -57,6 +58,109 @@ def _generate_return_type(verification: intermediate.Verification) -> Stripped:
     )
 
 
+def _type_parameter_name(argument: intermediate.Argument) -> Identifier:
+    """
+    Generate the name of the template parameter for the items of the ``argument``.
+
+    For example, ``items`` gives ``ItemsT``.
+    """
+    return Identifier(f"{cpp_naming.class_name(argument.name)}T")
+
+
+def _is_generic(verification: intermediate.VerificationUnion) -> bool:
+    """
+    Check whether the transpiled ``verification`` function is a template.
+
+    The verification function is a template if it has one or more generic
+    sequences, see :py:func:`intermediate.generic_sequence_item_class`.
+    The implementation-specific verification functions declare their templates
+    in their snippets.
+    """
+    return isinstance(verification, intermediate.TranspilableVerification) and any(
+        intermediate.generic_sequence_item_class(arg) is not None
+        for arg in verification.arguments
+    )
+
+
+def _generate_signature(
+    verification: Union[
+        intermediate.TranspilableVerification,
+        intermediate.PatternVerification,
+    ],
+) -> Stripped:
+    """
+    Generate the signature of the ``verification`` function.
+
+    The ``std::vector`` is invariant in C++, so we declare a template parameter
+    for the items of each generic sequence, see
+    :py:func:`intermediate.generic_sequence_item_class`. This way, the vectors of
+    the descendants can be passed without a copy. The virtual methods can not be
+    templates in C++, so only the verification functions have generic sequences.
+
+    The template parameters are constrained by ``static_assert``'s in the body
+    instead of ``std::enable_if`` in the signature so that the template can be
+    declared and defined separately.
+    """
+    type_parameters = []  # type: List[Identifier]
+    arg_definitions = []  # type: List[Stripped]
+    for arg in verification.arguments:
+        arg_name = cpp_naming.argument_name(arg.name)
+
+        if intermediate.generic_sequence_item_class(arg) is None:
+            arg_type = cpp_common.generate_argument_type(
+                argument=arg, types_namespace=cpp_common.TYPES_NAMESPACE
+            )
+        else:
+            type_parameter = _type_parameter_name(arg)
+            type_parameters.append(type_parameter)
+
+            vector_type = Stripped(
+                f"""\
+std::vector<
+{I}std::shared_ptr<{type_parameter}>
+>"""
+            )
+            if isinstance(arg.type_annotation, intermediate.OptionalTypeAnnotation):
+                arg_type = Stripped(
+                    f"""\
+const common::optional<
+{I}{indent_but_first_line(vector_type, I)}
+>&"""
+                )
+            else:
+                arg_type = Stripped(f"const {vector_type}&")
+
+        arg_definitions.append(Stripped(f"{arg_type} {arg_name}"))
+
+    function_name = cpp_naming.function_name(verification.name)
+    return_type = _generate_return_type(verification)
+
+    if len(arg_definitions) == 0:
+        signature = Stripped(f"{return_type} {function_name}()")
+    else:
+        arg_definitions_joined = ",\n".join(arg_definitions)
+        signature = Stripped(
+            f"""\
+{return_type} {function_name}(
+{I}{indent_but_first_line(arg_definitions_joined, I)}
+)"""
+        )
+
+    if len(type_parameters) == 0:
+        return signature
+
+    type_parameters_joined = ",\n".join(
+        f"typename {type_parameter}" for type_parameter in type_parameters
+    )
+    return Stripped(
+        f"""\
+template<
+{I}{indent_but_first_line(type_parameters_joined, I)}
+>
+{signature}"""
+    )
+
+
 @ensure(lambda result: (result[0] is not None) ^ (result[1] is not None))
 def _generate_verification_function_definition(
     verification: Union[
@@ -84,20 +188,21 @@ def _generate_verification_function_definition(
 
         return code, None
 
-    arg_types_names = [
-        (
-            cpp_common.generate_argument_type(
-                argument=arg, types_namespace=cpp_common.TYPES_NAMESPACE
-            ),
-            cpp_naming.argument_name(arg.name),
-        )
-        for arg in verification.arguments
-    ]
+    remarks_on_generic_sequences = []  # type: List[str]
+    for arg in verification.arguments:
+        item_cls = intermediate.generic_sequence_item_class(arg)
+        if item_cls is None:
+            continue
 
-    function_name = cpp_naming.function_name(verification.name)
-    arg_definitions_joined = ",\n".join(
-        f"{arg_type} {arg_name}" for arg_type, arg_name in arg_types_names
-    )
+        interface_name = (
+            f"{cpp_common.TYPES_NAMESPACE}::{cpp_naming.interface_name(item_cls.name)}"
+        )
+        remarks_on_generic_sequences.append(
+            f"\\tparam {_type_parameter_name(arg)} type of the items of "
+            f"\\p {cpp_naming.argument_name(arg.name)}, {interface_name} or one of "
+            f"its descendants, so that the vectors of the descendants can be passed "
+            f"without a copy, as std::vector is invariant"
+        )
 
     blocks = []  # type: List[Stripped]
     if verification.description is not None:
@@ -106,6 +211,7 @@ def _generate_verification_function_definition(
             context=cpp_description.Context(
                 namespace=cpp_common.VERIFICATION_NAMESPACE, cls_or_enum=None
             ),
+            extra_remarks=remarks_on_generic_sequences,
         )
         if errors is not None:
             return None, Error(
@@ -116,20 +222,16 @@ def _generate_verification_function_definition(
             )
         assert comment is not None
         blocks.append(comment)
-
-    return_type = _generate_return_type(verification)
-
-    if len(arg_types_names) == 0:
-        signature = Stripped(f"{return_type} {function_name}()")
-    else:
-        signature = Stripped(
-            f"""\
-{return_type} {function_name}(
-{I}{indent_but_first_line(arg_definitions_joined, I)}
-)"""
+    elif len(remarks_on_generic_sequences) > 0:
+        blocks.append(
+            cpp_description.documentation_comment(
+                Stripped("\n\n".join(remarks_on_generic_sequences))
+            )
         )
+    else:
+        pass
 
-    blocks.append(Stripped(f"{signature};"))
+    blocks.append(Stripped(f"{_generate_signature(verification)};"))
 
     return Stripped("\n".join(blocks)), None
 
@@ -171,12 +273,274 @@ def _generate_definition_of_verify_constrained_primitive(
  */"""
         )
 
-    return Stripped(
-        f"""\
-{documentation_comment}
-std::unique_ptr<IVerification> {verify_name}(
-{I}{arg_type} {arg_name}
+    return Stripped(
+        f"""\
+{documentation_comment}
+std::unique_ptr<IVerification> {verify_name}(
+{I}{arg_type} {arg_name}
+);"""
+    )
+
+
+def _check_no_calls_to_internal_verifications(
+    verification: intermediate.TranspilableVerification,
+    symbol_table: intermediate.SymbolTable,
+) -> List[Error]:
+    """
+    Check that the public generic ``verification`` calls no internal verification.
+
+    The public generic verification functions are templates defined in the header,
+    see :py:func:`_is_generic`, while the internal verification functions are
+    declared only in the implementation file.
+    """
+    errors = []  # type: List[Error]
+    for node_in_body in verification.parsed.body:
+        for node in parse_tree.over_nodes(node_in_body):
+            if not isinstance(node, parse_tree.FunctionCall):
+                continue
+
+            callee = symbol_table.verification_functions_by_name.get(
+                node.name.identifier, None
+            )
+            if (
+                callee is None
+                or callee.visibility is not intermediate.Visibility.INTERNAL
+            ):
+                continue
+
+            errors.append(
+                Error(
+                    node.original_node,
+                    f"The public verification function {verification.name!r} has "
+                    f"generic sequences, so we generate it in C++ as a template "
+                    f"defined in the header. However, it calls the internal "
+                    f"verification function {callee.name!r}, which is declared "
+                    f"only in the implementation file. Please make "
+                    f"{callee.name!r} public, or {verification.name!r} internal.",
+                )
+            )
+
+    return errors
+
+
+class _TranspilableVerificationTranspiler(cpp_transpilation.Transpiler):
+    """Transpile the body of a :class:`TranspilableVerification`."""
+
+    # fmt: off
+    @require(
+        lambda environment, verification:
+        all(
+            environment.find(arg.name) is not None
+            for arg in verification.arguments
+        ),
+        "All arguments defined in the environment"
+    )
+    # fmt: on
+    def __init__(
+        self,
+        type_map: Mapping[
+            parse_tree.Node, intermediate_type_inference.TypeAnnotationUnion
+        ],
+        is_optional_map: Mapping[parse_tree.Node, bool],
+        downcast_map: Mapping[parse_tree.Node, intermediate_type_inference.Downcast],
+        is_optional_before_downcast_map: Mapping[parse_tree.Node, bool],
+        environment: intermediate_type_inference.Environment,
+        symbol_table: intermediate.SymbolTable,
+        verification: intermediate.TranspilableVerification,
+        aliasing: cpp_aliasing.Aliasing,
+    ) -> None:
+        """Initialize with the given values."""
+        cpp_transpilation.Transpiler.__init__(
+            self,
+            type_map=type_map,
+            is_optional_map=is_optional_map,
+            downcast_map=downcast_map,
+            is_optional_before_downcast_map=is_optional_before_downcast_map,
+            environment=environment,
+            types_namespace=cpp_common.TYPES_NAMESPACE,
+            aliasing=aliasing,
+        )
+
+        self._symbol_table = symbol_table
+
+        self._argument_name_set = frozenset(arg.name for arg in verification.arguments)
+
+        # NOTE (mristin):
+        # The type inference propagates the very type annotation of the items of
+        # an argument to the loop variables, the generator variables and
+        # the indexed items, so we can tell by the identity of the type annotation
+        # that a value is of the template parameter of a generic sequence.
+        type_parameter_by_items_id = dict()  # type: Dict[int, Identifier]
+        for arg in verification.arguments:
+            if intermediate.generic_sequence_item_class(arg) is None:
+                continue
+
+            arg_type_anno = environment.find(arg.name)
+            assert arg_type_anno is not None
+
+            list_type_anno = intermediate_type_inference.beneath_optional(arg_type_anno)
+            assert isinstance(
+                list_type_anno, intermediate_type_inference.ListTypeAnnotation
+            )
+
+            type_parameter_by_items_id[id(list_type_anno.items)] = _type_parameter_name(
+                arg
+            )
+
+        self._type_parameter_by_items_id = type_parameter_by_items_id
+
+    def _type_parameter_of(
+        self, type_annotation: intermediate_type_inference.TypeAnnotationUnion
+    ) -> Optional[Identifier]:
+        return self._type_parameter_by_items_id.get(id(type_annotation), None)
+
+    def transform_name(
+        self, node: parse_tree.Name
+    ) -> Tuple[Optional[Stripped], Optional[Error]]:
+        if node.identifier in self._variable_name_set:
+            return Stripped(cpp_naming.variable_name(node.identifier)), None
+
+        if node.identifier in self._argument_name_set:
+            return Stripped(cpp_naming.argument_name(node.identifier)), None
+
+        if node.identifier in self._symbol_table.constants_by_name:
+            constant = cpp_naming.constant_name(node.identifier)
+            return Stripped(f"{cpp_common.CONSTANTS_NAMESPACE}::{constant}"), None
+
+        if node.identifier in self._symbol_table.verification_functions_by_name:
+            return Stripped(cpp_naming.function_name(node.identifier)), None
+
+        our_type = self._symbol_table.find_our_type(name=node.identifier)
+        if isinstance(our_type, intermediate.Enumeration):
+            return (
+                Stripped(
+                    f"{cpp_common.TYPES_NAMESPACE}::{cpp_naming.enum_name(node.identifier)}"
+                ),
+                None,
+            )
+
+        return None, Error(
+            node.original_node,
+            f"We can not determine how to transpile the name {node.identifier!r} "
+            f"to C++. We could not find it neither in the constants, nor in "
+            f"verification functions, nor as an enumeration. "
+            f"If you expect this name to be transpilable, please contact "
+            f"the developers.",
+        )
+
+
+@ensure(lambda result: (result[0] is not None) ^ (result[1] is not None))
+def _generate_implementation_of_transpilable_verification(
+    verification: intermediate.TranspilableVerification,
+    symbol_table: intermediate.SymbolTable,
+    base_environment: intermediate_type_inference.Environment,
+) -> Tuple[Optional[Stripped], Optional[Error]]:
+    """Transpile the verification to a function implementation."""
+    # fmt: off
+    type_inference, inference_error = (
+        intermediate_type_inference.infer_for_verification(
+            verification=verification,
+            base_environment=base_environment
+        )
+    )
+    # fmt: on
+
+    if inference_error is not None:
+        return None, inference_error
+
+    assert type_inference is not None
+
+    aliasing, aliasing_errors = cpp_aliasing.analyze(
+        body=verification.parsed.body,
+        arguments=verification.arguments,
+        type_map=type_inference.type_map,
+        binds_self=False,
+    )
+    if aliasing_errors is not None:
+        return None, Error(
+            verification.parsed.node,
+            f"Failed to transpile the verification function {verification.name!r} "
+            f"so that its C++ variables alias the values as in Python",
+            aliasing_errors,
+        )
+
+    assert aliasing is not None
+
+    optional_inferrer = cpp_optionaling.Inferrer(
+        environment=type_inference.environment_with_args,
+        type_map=type_inference.type_map,
+        downcast_map=type_inference.downcast_map,
+    )
+    for node in verification.parsed.body:
+        _ = optional_inferrer.transform(node)
+
+    if len(optional_inferrer.errors) > 0:
+        return None, Error(
+            verification.parsed.node,
+            f"Failed to infer whether one or more nodes are ``common::optional`` "
+            f"in the verification function {verification.name!r}",
+            optional_inferrer.errors,
+        )
+
+    transpiler = _TranspilableVerificationTranspiler(
+        type_map=type_inference.type_map,
+        is_optional_map=optional_inferrer.is_optional_map,
+        downcast_map=type_inference.downcast_map,
+        is_optional_before_downcast_map=(
+            optional_inferrer.is_optional_before_downcast_map
+        ),
+        environment=type_inference.environment_with_args,
+        symbol_table=symbol_table,
+        verification=verification,
+        aliasing=aliasing,
+    )
+
+    body = []  # type: List[Stripped]
+    for node in verification.parsed.body:
+        stmt, error = transpiler.transform(node)
+        if error is not None:
+            return None, Error(
+                verification.parsed.node,
+                f"Failed to transpile the verification function {verification.name!r}",
+                [error],
+            )
+
+        assert stmt is not None
+        body.append(stmt)
+
+    # NOTE (mristin):
+    # We constrain the template parameters of the generic sequences here instead
+    # of in the signature, see :py:func:`_generate_signature`.
+    static_asserts = []  # type: List[Stripped]
+    for arg in verification.arguments:
+        item_cls = intermediate.generic_sequence_item_class(arg)
+        if item_cls is None:
+            continue
+
+        interface_name = (
+            f"{cpp_common.TYPES_NAMESPACE}::{cpp_naming.interface_name(item_cls.name)}"
+        )
+        arg_name = cpp_naming.argument_name(arg.name)
+        static_asserts.append(
+            Stripped(
+                f"""\
+static_assert(
+{I}std::is_base_of<{interface_name}, {_type_parameter_name(arg)}>::value,
+{I}"Expected the items of {arg_name} to be instances of {interface_name}"
 );"""
+            )
+        )
+
+    body_joined = "\n".join([*static_asserts, *body])
+
+    return (
+        Stripped(
+            f"""\
+{_generate_signature(verification)} {{
+{I}{indent_but_first_line(body_joined, I)}
+}}"""
+        ),
+        None,
     )
 
 
@@ -198,14 +562,55 @@ def generate_header(
 
     include_guard_var = cpp_common.include_guard_var(namespace)
 
-    unordered_set_include = (
-        "#include <unordered_set>\n"
-        if intermediate_uses.sets_in(symbol_table.verification_functions)
-        else ""
-    )
-
     include_prefix_path = cpp_common.generate_include_prefix_path(library_namespace)
 
+    # NOTE (mristin):
+    # The public generic verification functions are templates, so we define them
+    # in the header, see :py:func:`_is_generic`. Their bodies need the same
+    # includes as the definitions in the implementation file.
+    public_generic_verifications = [
+        verification
+        for verification in symbol_table.verification_functions
+        if (
+            verification.visibility is intermediate.Visibility.PUBLIC
+            and _is_generic(verification)
+        )
+    ]
+
+    our_includes = [
+        f'#include "{include_prefix_path}/common.hpp"',
+        f'#include "{include_prefix_path}/iteration.hpp"',
+        f'#include "{include_prefix_path}/pattern.hpp"',
+        f'#include "{include_prefix_path}/types.hpp"',
+    ]
+
+    std_includes = ["<set>"]
+    if intermediate_uses.sets_in(symbol_table.verification_functions):
+        std_includes.append("<unordered_set>")
+
+    if len(public_generic_verifications) > 0:
+        our_includes.extend(
+            [
+                f'#include "{include_prefix_path}/constants.hpp"',
+                f'#include "{include_prefix_path}/stringification.hpp"',
+            ]
+        )
+
+        std_includes.extend(["<memory>", "<type_traits>", "<vector>"])
+
+        # NOTE (mristin):
+        # See the includes in :py:func:`generate_implementation`.
+        if intermediate_uses.abs_call(symbol_table):
+            std_includes.extend(["<cmath>", "<cstdlib>"])
+
+        if intermediate_uses.assert_statements_in(public_generic_verifications):
+            std_includes.append("<stdexcept>")
+
+    our_includes_joined = "\n".join(sorted(our_includes))
+    std_includes_joined = "\n".join(
+        f"#include {std_include}" for std_include in sorted(std_includes)
+    )
+
     blocks = [
         Stripped(
             f"""\
@@ -215,14 +620,10 @@ def generate_header(
         cpp_common.WARNING,
         Stripped(
             f"""\
-#include "{include_prefix_path}/common.hpp"
-#include "{include_prefix_path}/iteration.hpp"
-#include "{include_prefix_path}/pattern.hpp"
-#include "{include_prefix_path}/types.hpp"
+{our_includes_joined}
 
 #pragma warning(push, 0)
-#include <set>
-{unordered_set_include}\
+{std_includes_joined}
 #pragma warning(pop)"""
         ),
         cpp_common.generate_namespace_opening(library_namespace),
@@ -466,6 +867,46 @@ class RecursiveVerification : public IVerification {{
 
         blocks.append(Stripped("// endregion Verification functions"))
 
+    # NOTE (mristin):
+    # The templates need to be defined in the header so that the users of
+    # the library can instantiate them. We define them after all the declarations of
+    # the verification functions, since the templates look up the functions which
+    # they call at their definitions.
+    if len(public_generic_verifications) > 0:
+        blocks.append(
+            Stripped("// region Definitions of generic verification functions")
+        )
+
+        base_environment = intermediate_type_inference.populate_base_environment(
+            symbol_table=symbol_table
+        )
+
+        for verification in public_generic_verifications:
+            assert isinstance(verification, intermediate.TranspilableVerification)
+
+            internal_call_errors = _check_no_calls_to_internal_verifications(
+                verification=verification, symbol_table=symbol_table
+            )
+            if len(internal_call_errors) > 0:
+                errors.extend(internal_call_errors)
+                continue
+
+            block, error = _generate_implementation_of_transpilable_verification(
+                verification=verification,
+                symbol_table=symbol_table,
+                base_environment=base_environment,
+            )
+            if error is not None:
+                errors.append(error)
+                continue
+
+            assert block is not None
+            blocks.append(block)
+
+        blocks.append(
+            Stripped("// endregion Definitions of generic verification functions")
+        )
+
     if len(symbol_table.constrained_primitives) > 0:
         blocks.append(Stripped("// region Verification of constrained primitives"))
 
@@ -667,202 +1108,6 @@ def _generate_pattern_verification_implementation(
     )
 
 
-class _TranspilableVerificationTranspiler(cpp_transpilation.Transpiler):
-    """Transpile the body of a :class:`TranspilableVerification`."""
-
-    # fmt: off
-    @require(
-        lambda environment, verification:
-        all(
-            environment.find(arg.name) is not None
-            for arg in verification.arguments
-        ),
-        "All arguments defined in the environment"
-    )
-    # fmt: on
-    def __init__(
-        self,
-        type_map: Mapping[
-            parse_tree.Node, intermediate_type_inference.TypeAnnotationUnion
-        ],
-        is_optional_map: Mapping[parse_tree.Node, bool],
-        downcast_map: Mapping[parse_tree.Node, intermediate_type_inference.Downcast],
-        is_optional_before_downcast_map: Mapping[parse_tree.Node, bool],
-        environment: intermediate_type_inference.Environment,
-        symbol_table: intermediate.SymbolTable,
-        verification: intermediate.TranspilableVerification,
-        aliasing: cpp_aliasing.Aliasing,
-    ) -> None:
-        """Initialize with the given values."""
-        cpp_transpilation.Transpiler.__init__(
-            self,
-            type_map=type_map,
-            is_optional_map=is_optional_map,
-            downcast_map=downcast_map,
-            is_optional_before_downcast_map=is_optional_before_downcast_map,
-            environment=environment,
-            types_namespace=cpp_common.TYPES_NAMESPACE,
-            aliasing=aliasing,
-        )
-
-        self._symbol_table = symbol_table
-
-        self._argument_name_set = frozenset(arg.name for arg in verification.arguments)
-
-    def transform_name(
-        self, node: parse_tree.Name
-    ) -> Tuple[Optional[Stripped], Optional[Error]]:
-        if node.identifier in self._variable_name_set:
-            return Stripped(cpp_naming.variable_name(node.identifier)), None
-
-        if node.identifier in self._argument_name_set:
-            return Stripped(cpp_naming.argument_name(node.identifier)), None
-
-        if node.identifier in self._symbol_table.constants_by_name:
-            constant = cpp_naming.constant_name(node.identifier)
-            return Stripped(f"{cpp_common.CONSTANTS_NAMESPACE}::{constant}"), None
-
-        if node.identifier in self._symbol_table.verification_functions_by_name:
-            return Stripped(cpp_naming.function_name(node.identifier)), None
-
-        our_type = self._symbol_table.find_our_type(name=node.identifier)
-        if isinstance(our_type, intermediate.Enumeration):
-            return (
-                Stripped(
-                    f"{cpp_common.TYPES_NAMESPACE}::{cpp_naming.enum_name(node.identifier)}"
-                ),
-                None,
-            )
-
-        return None, Error(
-            node.original_node,
-            f"We can not determine how to transpile the name {node.identifier!r} "
-            f"to C++. We could not find it neither in the constants, nor in "
-            f"verification functions, nor as an enumeration. "
-            f"If you expect this name to be transpilable, please contact "
-            f"the developers.",
-        )
-
-
-@ensure(lambda result: (result[0] is not None) ^ (result[1] is not None))
-def _generate_implementation_of_transpilable_verification(
-    verification: intermediate.TranspilableVerification,
-    symbol_table: intermediate.SymbolTable,
-    base_environment: intermediate_type_inference.Environment,
-) -> Tuple[Optional[Stripped], Optional[Error]]:
-    """Transpile the verification to a function implementation."""
-    # fmt: off
-    type_inference, inference_error = (
-        intermediate_type_inference.infer_for_verification(
-            verification=verification,
-            base_environment=base_environment
-        )
-    )
-    # fmt: on
-
-    if inference_error is not None:
-        return None, inference_error
-
-    assert type_inference is not None
-
-    aliasing, aliasing_errors = cpp_aliasing.analyze(
-        body=verification.parsed.body,
-        arguments=verification.arguments,
-        type_map=type_inference.type_map,
-        binds_self=False,
-    )
-    if aliasing_errors is not None:
-        return None, Error(
-            verification.parsed.node,
-            f"Failed to transpile the verification function {verification.name!r} "
-            f"so that its C++ variables alias the values as in Python",
-            aliasing_errors,
-        )
-
-    assert aliasing is not None
-
-    optional_inferrer = cpp_optionaling.Inferrer(
-        environment=type_inference.environment_with_args,
-        type_map=type_inference.type_map,
-        downcast_map=type_inference.downcast_map,
-    )
-    for node in verification.parsed.body:
-        _ = optional_inferrer.transform(node)
-
-    if len(optional_inferrer.errors) > 0:
-        return None, Error(
-            verification.parsed.node,
-            f"Failed to infer whether one or more nodes are ``common::optional`` "
-            f"in the verification function {verification.name!r}",
-            optional_inferrer.errors,
-        )
-
-    transpiler = _TranspilableVerificationTranspiler(
-        type_map=type_inference.type_map,
-        is_optional_map=optional_inferrer.is_optional_map,
-        downcast_map=type_inference.downcast_map,
-        is_optional_before_downcast_map=(
-            optional_inferrer.is_optional_before_downcast_map
-        ),
-        environment=type_inference.environment_with_args,
-        symbol_table=symbol_table,
-        verification=verification,
-        aliasing=aliasing,
-    )
-
-    body = []  # type: List[Stripped]
-    for node in verification.parsed.body:
-        stmt, error = transpiler.transform(node)
-        if error is not None:
-            return None, Error(
-                verification.parsed.node,
-                f"Failed to transpile the verification function {verification.name!r}",
-                [error],
-            )
-
-        assert stmt is not None
-        body.append(stmt)
-
-    arg_types_names = [
-        (
-            cpp_common.generate_argument_type(
-                argument=arg, types_namespace=cpp_common.TYPES_NAMESPACE
-            ),
-            cpp_naming.argument_name(arg.name),
-        )
-        for arg in verification.arguments
-    ]
-
-    function_name = cpp_naming.function_name(verification.name)
-    arg_definitions_joined = ",\n".join(
-        f"{arg_type} {arg_name}" for arg_type, arg_name in arg_types_names
-    )
-
-    body_joined = "\n".join(body)
-
-    return_type = _generate_return_type(verification)
-
-    if len(arg_types_names) == 0:
-        signature = Stripped(f"{return_type} {function_name}()")
-    else:
-        signature = Stripped(
-            f"""\
-{return_type} {function_name}(
-{I}{indent_but_first_line(arg_definitions_joined, I)}
-)"""
-        )
-
-    return (
-        Stripped(
-            f"""\
-{signature} {{
-{I}{indent_but_first_line(body_joined, I)}
-}}"""
-        ),
-        None,
-    )
-
-
 class _InvariantTranspiler(cpp_transpilation.Transpiler):
     """
     Transpile invariants of the classes and of the constrained primitives.
@@ -3439,6 +3684,15 @@ def generate_implementation(
                 )
 
             elif isinstance(verification, intermediate.TranspilableVerification):
+                # NOTE (mristin):
+                # The public generic verification functions are templates defined
+                # in the header, see :py:func:`generate_header`.
+                if (
+                    _is_generic(verification)
+                    and verification.visibility is intermediate.Visibility.PUBLIC
+                ):
+                    continue
+
                 block, error = _generate_implementation_of_transpilable_verification(
                     verification=verification,
                     symbol_table=symbol_table,
diff --git a/aas_core_codegen/cpp/transpilation.py b/aas_core_codegen/cpp/transpilation.py
index f6d12662b..47702cec7 100644
--- a/aas_core_codegen/cpp/transpilation.py
+++ b/aas_core_codegen/cpp/transpilation.py
@@ -465,6 +465,27 @@ def __init__(
         # While this class does not directly use it, the descendants of this class do!
         self._variable_name_set = set()  # type: Set[Identifier]
 
+    def _type_parameter_of(
+        self, type_annotation: intermediate_type_inference.TypeAnnotationUnion
+    ) -> Optional[Identifier]:
+        """
+        Determine the template parameter which stands for the ``type_annotation``.
+
+        Only the verification functions are templates, namely over the items of
+        the generic sequences, see :py:func:`intermediate.generic_sequence_item_class`.
+        The transpiler of the verification functions overrides this method.
+
+        We declare the loop and the generator variables over a generic sequence with
+        the template parameter so that the items are not converted to
+        temporary shared pointers of the parent class.
+
+        :param type_annotation: inferred type of a value
+        :return:
+            the template parameter, if the value is an item of a generic sequence,
+            and None otherwise
+        """
+        return None
+
     def _transform_enumeration_literal(
         self, enumeration_name: Identifier, literal_name: Identifier
     ) -> Stripped:
@@ -1207,6 +1228,52 @@ def transform_is_in(
         if isinstance(container_type, intermediate_type_inference.ListTypeAnnotation):
             member = self._as_int64_position(node.member, member)
 
+        # NOTE (mristin):
+        # The ``std::find`` compares the shared pointers by their raw pointers, so
+        # the classes of the items and of the member need to be related. This holds
+        # for the declared classes, as the type inference checks that one is
+        # a subclass of the other. However, the template parameter of a generic
+        # sequence, see :py:func:`intermediate.generic_sequence_item_class`, can be
+        # any descendant, *e.g.*, a sibling of the class of the member. Hence, we
+        # convert the member to the more general of the two declared classes.
+        member_type = self.type_map[node.member]
+        if (
+            isinstance(container_type, intermediate_type_inference.ListTypeAnnotation)
+            and isinstance(
+                container_type.items, intermediate_type_inference.OurTypeAnnotation
+            )
+            and isinstance(container_type.items.our_type, intermediate.Class)
+            and isinstance(member_type, intermediate_type_inference.OurTypeAnnotation)
+            and isinstance(member_type.our_type, intermediate.Class)
+            and (
+                self._type_parameter_of(container_type.items) is not None
+                or self._type_parameter_of(member_type) is not None
+            )
+        ):
+            general_type = (
+                container_type.items
+                if member_type.our_type.is_subclass_of(container_type.items.our_type)
+                else member_type
+            )
+
+            general_type_cpp, error_msg = generate_type(
+                type_annotation=intermediate_type_inference.OurTypeAnnotation(
+                    our_type=general_type.our_type
+                ),
+                types_namespace=self._types_namespace,
+            )
+            if error_msg is not None:
+                return None, Error(node.member.original_node, error_msg)
+
+            assert general_type_cpp is not None
+
+            member = Stripped(
+                f"""\
+{general_type_cpp}(
+{I}{indent_but_first_line(member, I)}
+)"""
+            )
+
         contains_function = cpp_naming.function_name(Identifier("contains"))
 
         return (
@@ -1694,6 +1761,49 @@ def transform_function_call(
 
             assert function_name is not None
 
+            # NOTE (mristin):
+            # A transpiled verification function is a template over the items of
+            # its generic sequences, see
+            # :py:func:`intermediate.generic_sequence_item_class`. C++ deduces
+            # the template parameters without any implicit conversions, so we pass
+            # ``None`` to an optional generic sequence as a typed empty optional,
+            # and a required vector through ``common::make_optional``.
+            if isinstance(func_type.func, intermediate.TranspilableVerification):
+                for i, (arg_node, argument) in enumerate(
+                    zip(node.args, func_type.func.arguments)
+                ):
+                    if intermediate.generic_sequence_item_class(argument) is None:
+                        continue
+
+                    if not isinstance(
+                        argument.type_annotation, intermediate.OptionalTypeAnnotation
+                    ):
+                        continue
+
+                    if (
+                        isinstance(arg_node, parse_tree.Constant)
+                        and arg_node.value is None
+                    ):
+                        optional_type = cpp_common.generate_type(
+                            type_annotation=argument.type_annotation,
+                            types_namespace=self._types_namespace,
+                        )
+                        args[i] = Stripped(f"{optional_type}()")
+
+                    elif not isinstance(
+                        self.type_map[arg_node],
+                        intermediate_type_inference.OptionalTypeAnnotation,
+                    ):
+                        args[i] = Stripped(
+                            f"""\
+common::make_optional(
+{I}{indent_but_first_line(args[i], I)}
+)"""
+                        )
+
+                    else:
+                        pass
+
             if len(args) == 0:
                 return Stripped(f"{function_name}()"), None
 
@@ -2425,8 +2535,18 @@ def _transform_any_or_all(
             cpp_aliasing.Declaration.MUT_REF
         )
 
+        type_parameter = self._type_parameter_of(variable_type_annotation)
+
         variable_type_cpp: Optional[Stripped]
-        if self._declaration(node.generator) is cpp_aliasing.Declaration.COPY:
+        error_msg: Optional[str]
+        if type_parameter is not None:
+            variable_type_cpp = Stripped(f"std::shared_ptr<{type_parameter}>")
+            error_msg = None
+
+            if self._declaration(node.generator) is not cpp_aliasing.Declaration.COPY:
+                variable_type_cpp = Stripped(f"const {variable_type_cpp}&")
+
+        elif self._declaration(node.generator) is cpp_aliasing.Declaration.COPY:
             variable_type_cpp, error_msg = generate_type(
                 type_annotation=variable_type_annotation,
                 types_namespace=self._types_namespace,
@@ -2749,6 +2869,27 @@ def transform_assignment(
 
             assert declared_type is not None
 
+            # NOTE (mristin):
+            # An immutable alias of a generic sequence shares its type annotation,
+            # see :py:meth:`intermediate_type_inference._Inferrer.transform_assignment`,
+            # so we declare the alias with the template parameter as well.
+            target_type_beneath = intermediate_type_inference.beneath_optional(
+                target_type
+            )
+            if isinstance(
+                target_type_beneath, intermediate_type_inference.ListTypeAnnotation
+            ):
+                type_parameter = self._type_parameter_of(target_type_beneath.items)
+                if type_parameter is not None:
+                    declared_type = Stripped(
+                        f"std::vector<std::shared_ptr<{type_parameter}> >"
+                    )
+
+                    if isinstance(
+                        target_type, intermediate_type_inference.OptionalTypeAnnotation
+                    ):
+                        declared_type = Stripped(f"common::optional<{declared_type} >")
+
             # NOTE (mristin):
             # A variable declared as ``Final[...]`` is neither re-assigned nor
             # mutated, so we can declare it as ``const``.
@@ -3104,10 +3245,18 @@ def transform_for(
 
         header: Optional[str] = None
         if isinstance(node.generator, parse_tree.ForEach):
-            variable_type_cpp, error_msg = generate_type(
-                type_annotation=variable_type_annotation,
-                types_namespace=self._types_namespace,
-            )
+            type_parameter = self._type_parameter_of(variable_type_annotation)
+
+            variable_type_cpp: Optional[Stripped]
+            error_msg: Optional[str]
+            if type_parameter is not None:
+                variable_type_cpp = Stripped(f"std::shared_ptr<{type_parameter}>")
+                error_msg = None
+            else:
+                variable_type_cpp, error_msg = generate_type(
+                    type_annotation=variable_type_annotation,
+                    types_namespace=self._types_namespace,
+                )
             if error_msg is not None:
                 errors.append(Error(node.generator.variable.original_node, error_msg))
 
diff --git a/aas_core_codegen/csharp/lib/_generate_verification.py b/aas_core_codegen/csharp/lib/_generate_verification.py
index 658bb0d31..514b83c21 100644
--- a/aas_core_codegen/csharp/lib/_generate_verification.py
+++ b/aas_core_codegen/csharp/lib/_generate_verification.py
@@ -472,10 +472,41 @@ def _transpile_transpilable_verification(
         assert stmt is not None
         body.append(stmt)
 
+    # NOTE (mristin):
+    # The ``List<T>`` is invariant in C#, so we declare the generic sequences,
+    # see :py:func:`intermediate.generic_sequence_item_class`, as the covariant
+    # ``IReadOnlyList<T>``. This way, the lists of the descendants can be passed
+    # without a copy, as ``List<T>`` implements ``IReadOnlyList<T>``.
+    arg_defs = []  # type: List[Stripped]
+    remarks_on_generic_sequences = []  # type: List[str]
+    for arg in verification.arguments:
+        arg_name = csharp_naming.argument_name(arg.name)
+
+        if intermediate.generic_sequence_item_class(arg) is None:
+            arg_type = csharp_common.generate_type(arg.type_annotation)
+        else:
+            list_type_anno = intermediate.beneath_optional(arg.type_annotation)
+            assert isinstance(list_type_anno, intermediate.ListTypeAnnotation)
+
+            item_type = csharp_common.generate_type(list_type_anno.items)
+
+            arg_type = Stripped(f"IReadOnlyList<{item_type}>")
+            if isinstance(arg.type_annotation, intermediate.OptionalTypeAnnotation):
+                arg_type = Stripped(f"{arg_type}?")
+
+            remarks_on_generic_sequences.append(
+                f"The argument {arg_name} is declared as the covariant "
+                f"IReadOnlyList<{item_type}> instead of the invariant "
+                f"List<{item_type}> so that the lists of the descendants of "
+                f"{item_type} can be passed without a copy."
+            )
+
+        arg_defs.append(Stripped(f"{arg_type} {arg_name}"))
+
     writer = io.StringIO()
     if verification.description is not None:
         comment, comment_errors = csharp_description.generate_comment_for_signature(
-            verification.description
+            verification.description, extra_remarks=remarks_on_generic_sequences
         )
         if comment_errors is not None:
             return None, Error(
@@ -488,6 +519,15 @@ def _transpile_transpilable_verification(
 
         writer.write(comment)
         writer.write("\n")
+    elif len(remarks_on_generic_sequences) > 0:
+        writer.write(
+            csharp_description.generate_comment_for_remarks(
+                remarks_on_generic_sequences
+            )
+        )
+        writer.write("\n")
+    else:
+        pass
 
     method_name = csharp_naming.method_name(verification.name)
 
@@ -502,12 +542,6 @@ def _transpile_transpilable_verification(
     else:
         return_type = csharp_common.generate_type(type_annotation=verification.returns)
 
-    arg_defs = []  # type: List[Stripped]
-    for arg in verification.arguments:
-        arg_type = csharp_common.generate_type(arg.type_annotation)
-        arg_name = csharp_naming.argument_name(arg.name)
-        arg_defs.append(Stripped(f"{arg_type} {arg_name}"))
-
     if len(arg_defs) == 0:
         writer.write(
             f"""\
diff --git a/aas_core_codegen/csharp/transpilation.py b/aas_core_codegen/csharp/transpilation.py
index 14ae6cca6..244792867 100644
--- a/aas_core_codegen/csharp/transpilation.py
+++ b/aas_core_codegen/csharp/transpilation.py
@@ -1860,6 +1860,19 @@ def transform_assignment(
             target, error = self.transform_name(node=node.target)
             if error is not None:
                 errors.append(error)
+            elif (
+                node.annotation is not None
+                and isinstance(node.value, parse_tree.Name)
+                and self.type_map[node.target] is self.type_map[node.value]
+            ):
+                # NOTE (mristin):
+                # An immutable alias shares the type annotation of the aliased
+                # variable, see
+                # :py:meth:`intermediate_type_inference._Inferrer.transform_assignment`,
+                # so we infer its type with ``var``. This way, the alias of a generic
+                # sequence is also declared as ``IReadOnlyList<T>``, see
+                # :py:func:`intermediate.generic_sequence_item_class`.
+                target = Stripped(f"var {target}")
             elif node.annotation is not None:
                 # NOTE (mristin):
                 # We spell out the declared type, as it might differ from the type
diff --git a/aas_core_codegen/golang/lib/_generate_common.py b/aas_core_codegen/golang/lib/_generate_common.py
index 98f7b0837..7d1e002ab 100644
--- a/aas_core_codegen/golang/lib/_generate_common.py
+++ b/aas_core_codegen/golang/lib/_generate_common.py
@@ -382,6 +382,24 @@ def generate(symbol_table: intermediate.SymbolTable) -> str:
 {II}}}
 {I}}}
 {I}return false
+}}"""
+        ),
+        Stripped(
+            f"""\
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {{
+{I}for _, item := range s {{
+{II}if any(item) == v {{
+{III}return true
+{II}}}
+{I}}}
+{I}return false
 }}"""
         ),
         Stripped(
diff --git a/aas_core_codegen/golang/lib/_generate_verification.py b/aas_core_codegen/golang/lib/_generate_verification.py
index f78d9d4d1..c5874dd95 100644
--- a/aas_core_codegen/golang/lib/_generate_verification.py
+++ b/aas_core_codegen/golang/lib/_generate_verification.py
@@ -11,6 +11,7 @@
     Mapping,
     Union,
     Set,
+    Dict,
 )
 
 from icontract import ensure, require
@@ -411,6 +412,15 @@ def _transpile_pattern_verification(
     return Stripped(writer.getvalue()), None
 
 
+def _type_parameter_name(argument: intermediate.Argument) -> Identifier:
+    """
+    Generate the name of the type parameter for the items of the ``argument``.
+
+    For example, ``items`` gives ``ItemsT``.
+    """
+    return Identifier(f"{golang_naming.function_name(argument.name)}T")
+
+
 class _TranspilableVerificationTranspiler(golang_transpilation.Transpiler):
     """Transpile the body of a :py:class:`TranspilableVerification`."""
 
@@ -449,6 +459,35 @@ def __init__(
 
         self._argument_name_set = frozenset(arg.name for arg in verification.arguments)
 
+        # NOTE (mristin):
+        # The type inference propagates the very type annotation of the items of
+        # an argument to the loop variables, the generator variables and
+        # the indexed items, so we can tell by the identity of the type annotation
+        # that a value is of the type parameter of a generic sequence.
+        type_parameter_by_items_id = dict()  # type: Dict[int, Identifier]
+        for arg in verification.arguments:
+            if intermediate.generic_sequence_item_class(arg) is None:
+                continue
+
+            arg_type_anno = environment.find(arg.name)
+            assert arg_type_anno is not None
+
+            list_type_anno = intermediate_type_inference.beneath_optional(arg_type_anno)
+            assert isinstance(
+                list_type_anno, intermediate_type_inference.ListTypeAnnotation
+            )
+
+            type_parameter_by_items_id[id(list_type_anno.items)] = _type_parameter_name(
+                arg
+            )
+
+        self._type_parameter_by_items_id = type_parameter_by_items_id
+
+    def _type_parameter_of(
+        self, type_annotation: intermediate_type_inference.TypeAnnotationUnion
+    ) -> Optional[Identifier]:
+        return self._type_parameter_by_items_id.get(id(type_annotation), None)
+
     def _transform_enumeration_literal(
         self, enumeration_name: Identifier, literal_name: Identifier
     ) -> Stripped:
@@ -548,6 +587,46 @@ def _transpile_transpilable_verification(
         assert stmt is not None
         body.append(stmt)
 
+    # NOTE (mristin):
+    # The slices are invariant in Go, so we declare a type parameter for the items
+    # of each generic sequence, see :py:func:`intermediate.generic_sequence_item_class`.
+    # This way, the slices of the descendants can be passed without a copy.
+    # The methods can not have type parameters in Go, so only the verification
+    # functions have generic sequences.
+    arg_defs = []  # type: List[Stripped]
+    type_parameter_defs = []  # type: List[Stripped]
+    remarks_on_generic_sequences = []  # type: List[str]
+    for arg in verification.arguments:
+        arg_name = golang_naming.argument_name(arg.name)
+
+        if intermediate.generic_sequence_item_class(arg) is None:
+            arg_type = golang_common.generate_type(
+                arg.type_annotation, types_package=Identifier("ourtypes")
+            )
+        else:
+            list_type_anno = intermediate.beneath_optional(arg.type_annotation)
+            assert isinstance(list_type_anno, intermediate.ListTypeAnnotation)
+
+            item_type = golang_common.generate_type(
+                list_type_anno.items, types_package=Identifier("ourtypes")
+            )
+
+            type_parameter = _type_parameter_name(arg)
+            type_parameter_defs.append(Stripped(f"{type_parameter} {item_type}"))
+
+            # NOTE (mristin):
+            # The optional slices are not pointers in Go, as the slices are nilable.
+            arg_type = Stripped(f"[]{type_parameter}")
+
+            remarks_on_generic_sequences.append(
+                f"The items of the argument {arg_name} are of the type parameter "
+                f"{type_parameter} instead of {item_type} so that the slices of "
+                f"the descendants of {item_type} can be passed without a copy, as "
+                f"the slices are invariant in Go."
+            )
+
+        arg_defs.append(Stripped(f"{arg_name} {arg_type}"))
+
     writer = io.StringIO()
 
     if verification.description is not None:
@@ -557,6 +636,7 @@ def _transpile_transpilable_verification(
                 package=golang_common.VERIFICATION_PACKAGE,
                 cls_or_enum=None,
             ),
+            extra_remarks=remarks_on_generic_sequences,
         )
         if comment_errors is not None:
             return None, Error(
@@ -570,9 +650,22 @@ def _transpile_transpilable_verification(
 
         writer.write(comment)
         writer.write("\n")
+    elif len(remarks_on_generic_sequences) > 0:
+        writer.write(
+            golang_description.documentation_comment(
+                Stripped("\n\n".join(remarks_on_generic_sequences))
+            )
+        )
+        writer.write("\n")
+    else:
+        pass
 
     function_name = golang_naming.function_name(verification.name)
 
+    type_parameters = (
+        f"[{', '.join(type_parameter_defs)}]" if len(type_parameter_defs) > 0 else ""
+    )
+
     if verification.returns is None:
         return_type_suffix = ""
     else:
@@ -581,24 +674,16 @@ def _transpile_transpilable_verification(
         )
         return_type_suffix = f" {return_type}"
 
-    arg_defs = []  # type: List[Stripped]
-    for arg in verification.arguments:
-        arg_type = golang_common.generate_type(
-            arg.type_annotation, types_package=Identifier("ourtypes")
-        )
-        arg_name = golang_naming.argument_name(arg.name)
-        arg_defs.append(Stripped(f"{arg_name} {arg_type}"))
-
     if len(arg_defs) == 0:
         writer.write(
             f"""\
-func {function_name}(){return_type_suffix} {{"""
+func {function_name}{type_parameters}(){return_type_suffix} {{"""
         )
     else:
         arg_defs_joined = "\n".join(f"{arg_def}," for arg_def in arg_defs)
         writer.write(
             f"""\
-func {function_name}(
+func {function_name}{type_parameters}(
 {I}{indent_but_first_line(arg_defs_joined, I)}
 ){return_type_suffix} {{"""
         )
diff --git a/aas_core_codegen/golang/transpilation.py b/aas_core_codegen/golang/transpilation.py
index de362bd3f..42f9e6de2 100644
--- a/aas_core_codegen/golang/transpilation.py
+++ b/aas_core_codegen/golang/transpilation.py
@@ -256,6 +256,24 @@ def __init__(
         # generate the reference in the Go code.
         self._variable_name_set = set()  # type: Set[Identifier]
 
+    def _type_parameter_of(
+        self, type_annotation: intermediate_type_inference.TypeAnnotationUnion
+    ) -> Optional[Identifier]:
+        """
+        Determine the type parameter which stands for the ``type_annotation``.
+
+        Only the verification functions have type parameters, namely for the items
+        of the generic sequences, see
+        :py:func:`intermediate.generic_sequence_item_class`. The transpiler of
+        the verification functions overrides this method.
+
+        :param type_annotation: inferred type of a value
+        :return:
+            the type parameter, if the value is an item of a generic sequence,
+            and None otherwise
+        """
+        return None
+
     def _our_type_name(self, name: Identifier) -> Stripped:
         """Prepend the types package, if specified, to the ``name`` of our type."""
         if self._types_package is None:
@@ -309,6 +327,12 @@ def transform(
 
         source_type = downcast.source.our_type
         if isinstance(source_type, intermediate.Class):
+            # NOTE (mristin):
+            # Go forbids type assertions on the values of a type parameter, so we
+            # convert the item of a generic sequence to an interface first.
+            if self._type_parameter_of(downcast.source) is not None:
+                return Stripped(f"any({code}).({interface_name})"), None
+
             return Stripped(f"{code}.({interface_name})"), None
 
         elif isinstance(source_type, intermediate.NamedUnion):
@@ -808,10 +832,24 @@ def transform_is_in(
             )
 
         elif isinstance(container_type, intermediate_type_inference.ListTypeAnnotation):
+            # NOTE (mristin):
+            # The ``ourcommon.SliceContains`` infers its type parameter from both
+            # the slice and the member, so that the untyped constants take the type of
+            # the items. The instances of the classes are never constants, but they
+            # can be of a different type than the items, *e.g.*, if the items are of
+            # the type parameter of a generic sequence, see
+            # :py:func:`intermediate.generic_sequence_item_class`, or if the member
+            # is an instance of a descendant. Hence, we look them up as ``any``'s.
+            function_name = "SliceContains"
+            if isinstance(
+                container_type.items, intermediate_type_inference.OurTypeAnnotation
+            ) and isinstance(container_type.items.our_type, intermediate.Class):
+                function_name = "SliceContainsInstance"
+
             return (
                 Stripped(
                     f"""\
-ourcommon.SliceContains(
+ourcommon.{function_name}(
 {I}{indent_but_first_line(container, I)},
 {I}{indent_but_first_line(member, I)},
 )"""
@@ -1146,6 +1184,32 @@ def transform_function_call(
 
         args = []  # type: List[Stripped]
         for i, arg_node in enumerate(node.args):
+            # NOTE (mristin):
+            # The type parameter of a generic sequence can not be inferred from
+            # an untyped ``nil``, so we pass on a typed ``nil`` instead, see
+            # :py:func:`intermediate.generic_sequence_item_class`.
+            if (
+                isinstance(
+                    func_type, intermediate_type_inference.VerificationTypeAnnotation
+                )
+                and isinstance(arg_node, parse_tree.Constant)
+                and arg_node.value is None
+                and intermediate.generic_sequence_item_class(
+                    func_type.func.arguments[i]
+                )
+                is not None
+            ):
+                list_type_anno = intermediate.beneath_optional(
+                    func_type.func.arguments[i].type_annotation
+                )
+                assert isinstance(list_type_anno, intermediate.ListTypeAnnotation)
+
+                list_type = golang_common.generate_type(
+                    type_annotation=list_type_anno, types_package=self._types_package
+                )
+                args.append(Stripped(f"{list_type}(nil)"))
+                continue
+
             # NOTE (mristin):
             # We pass on a pointer to an optional argument of a verification
             # function, and de-reference the values otherwise.
@@ -2066,11 +2130,22 @@ def _transform_any_or_all(
         variable_type_annotation = self.type_map[node.generator.variable]
 
         variable_name_go = golang_naming.variable_name(variable_name)
-        variable_type_go, error_msg = generate_type(
-            type_annotation=variable_type_annotation, types_package=self._types_package
-        )
-        if error_msg is not None:
-            errors.append(Error(node.generator.variable.original_node, error_msg))
+
+        # NOTE (mristin):
+        # The items of a generic sequence are of the type parameter, and
+        # the ``ourcommon.All`` and ``ourcommon.Some`` infer their type from both
+        # the condition and the slice, so the condition needs to expect the type
+        # parameter as well.
+        type_parameter = self._type_parameter_of(variable_type_annotation)
+        if type_parameter is not None:
+            variable_type_go = Stripped(type_parameter)  # type: Optional[Stripped]
+        else:
+            variable_type_go, error_msg = generate_type(
+                type_annotation=variable_type_annotation,
+                types_package=self._types_package,
+            )
+            if error_msg is not None:
+                errors.append(Error(node.generator.variable.original_node, error_msg))
 
         try:
             self._environment.set(
@@ -2410,6 +2485,21 @@ def transform_assignment(
             if error_msg is not None:
                 return None, Error(node.annotation.original_node, error_msg)
 
+            # NOTE (mristin):
+            # An immutable alias of a generic sequence shares its type annotation,
+            # see :py:meth:`intermediate_type_inference._Inferrer.transform_assignment`,
+            # so we declare the alias with the type parameter as well. The optional
+            # slices are not pointers, as the slices are nilable.
+            target_type_beneath = intermediate_type_inference.beneath_optional(
+                self.type_map[node.target]
+            )
+            if isinstance(
+                target_type_beneath, intermediate_type_inference.ListTypeAnnotation
+            ):
+                type_parameter = self._type_parameter_of(target_type_beneath.items)
+                if type_parameter is not None:
+                    declared_type = Stripped(f"[]{type_parameter}")
+
             target = Stripped(f"var {target} {declared_type}")
             assignment = "="
 
diff --git a/aas_core_codegen/intermediate/__init__.py b/aas_core_codegen/intermediate/__init__.py
index 3304b2561..ae47e1e8e 100644
--- a/aas_core_codegen/intermediate/__init__.py
+++ b/aas_core_codegen/intermediate/__init__.py
@@ -77,6 +77,7 @@
 try_primitive_type = _types.try_primitive_type
 try_constrained_primitive = _types.try_constrained_primitive
 map_descendability = _types.map_descendability
+generic_sequence_item_class = _types.generic_sequence_item_class
 collect_ids_of_our_types_in_properties = _types.collect_ids_of_our_types_in_properties
 over_type_annotation_and_nested_type_annotations = (
     _types.over_type_annotation_and_nested_type_annotations
diff --git a/aas_core_codegen/intermediate/_types.py b/aas_core_codegen/intermediate/_types.py
index 82df4ac91..8a167e510 100644
--- a/aas_core_codegen/intermediate/_types.py
+++ b/aas_core_codegen/intermediate/_types.py
@@ -3855,6 +3855,51 @@ def try_constrained_primitive(
     return None
 
 
+def generic_sequence_item_class(argument: Argument) -> Optional["ClassUnion"]:
+    """
+    Determine the class of the items if the ``argument`` is a generic sequence.
+
+    A generic sequence is a read-only ``Sequence[...]`` of instances of a class
+    with descendants, possibly beneath ``Optional[...]``. The verification functions
+    accept the sequences of the descendants for such an argument, as the type
+    inference allows it in :py:mod:`aas_core_codegen.intermediate.type_inference`.
+
+    Python and TypeScript accept the sequences of the descendants for free, as their
+    read-only sequences are covariant. The lists of the other targets are invariant,
+    so they declare the argument generic: Go with a type parameter, C++ with
+    a template defined in the header, C# with the covariant ``IReadOnlyList<T>``, and
+    Java with the wildcard ``List<? extends T>``. None of them copies the sequence.
+
+    The methods can not have generic arguments, since Go methods can not have type
+    parameters, and C++ virtual methods can not be templates. Hence, the generators
+    should check this only for the verification functions.
+
+    A mutable ``List[...]`` is never generic, since the callee could insert into it
+    an instance which is not of the caller's subclass.
+
+    :param argument: of a verification function
+    :return: the class of the items, if the argument is a generic sequence
+    """
+    if argument.mutable:
+        return None
+
+    type_anno = beneath_optional(argument.type_annotation)
+    if not isinstance(type_anno, ListTypeAnnotation):
+        return None
+
+    if not isinstance(type_anno.items, OurTypeAnnotation):
+        return None
+
+    our_type = type_anno.items.our_type
+    if not isinstance(our_type, (AbstractClass, ConcreteClass)):
+        return None
+
+    if len(our_type.descendant_id_set) == 0:
+        return None
+
+    return our_type
+
+
 def map_descendability(
     type_annotation: TypeAnnotationUnion,
 ) -> MutableMapping[TypeAnnotationUnion, bool]:
diff --git a/aas_core_codegen/intermediate/type_inference.py b/aas_core_codegen/intermediate/type_inference.py
index 47b161096..2950b9119 100644
--- a/aas_core_codegen/intermediate/type_inference.py
+++ b/aas_core_codegen/intermediate/type_inference.py
@@ -976,6 +976,46 @@ def _assignable(
     return False
 
 
+def _is_list_of_descendants(
+    target_type: "TypeAnnotationUnion", value_type: "TypeAnnotationUnion"
+) -> bool:
+    """
+    Check that the ``value_type`` is a list of the descendants of the items of
+    the ``target_type``.
+
+    An optional value can be passed only to an optional target.
+    """
+    if isinstance(value_type, OptionalTypeAnnotation) and not isinstance(
+        target_type, OptionalTypeAnnotation
+    ):
+        return False
+
+    target_type_beneath = beneath_optional(target_type)
+    value_type_beneath = beneath_optional(value_type)
+
+    if not (
+        isinstance(target_type_beneath, ListTypeAnnotation)
+        and isinstance(value_type_beneath, ListTypeAnnotation)
+    ):
+        return False
+
+    target_items = target_type_beneath.items
+    value_items = value_type_beneath.items
+
+    if not (
+        isinstance(target_items, OurTypeAnnotation)
+        and isinstance(target_items.our_type, _types.Class)
+        and isinstance(value_items, OurTypeAnnotation)
+        and isinstance(value_items.our_type, _types.Class)
+    ):
+        return False
+
+    return (
+        _types.runtime_id(value_items.our_type)
+        in target_items.our_type.descendant_id_set
+    )
+
+
 def needs_wrapping_into_named_union(
     target_type: "TypeAnnotationUnion", value_type: "TypeAnnotationUnion"
 ) -> bool:
@@ -2289,22 +2329,6 @@ def _can_be_mutated(type_annotation: "TypeAnnotationUnion") -> bool:
 )  # type: Final
 
 
-def _holds_set(type_annotation: "TypeAnnotationUnion") -> bool:
-    """Check whether a value of ``type_annotation`` is or contains a set at any depth."""
-    type_anno = beneath_optional(type_annotation)
-
-    if isinstance(type_anno, SetTypeAnnotation):
-        return True
-
-    if isinstance(type_anno, ListTypeAnnotation):
-        return _holds_set(type_anno.items)
-
-    if isinstance(type_anno, TupleTypeAnnotation):
-        return any(_holds_set(item) for item in type_anno.items)
-
-    return False
-
-
 def _holds_list_or_set(type_annotation: "TypeAnnotationUnion") -> bool:
     """Check whether a value of ``type_annotation`` is or contains a list or a set."""
     type_anno = beneath_optional(type_annotation)
@@ -4334,41 +4358,78 @@ def _transform_builtin_method_call(
         self.type_map[node] = result
         return result
 
-    def _check_arguments(
+    def _check_call_arguments(
         self,
         args: Sequence[parse_tree.Expression],
-        arguments: Sequence[_types.Argument],
-        what: str,
+        callee: Union[_types.Verification, _types.Method],
     ) -> bool:
         """
-        Check that the ``args`` fit the ``arguments`` beyond their types.
+        Check that the ``args`` fit the arguments of the ``callee``.
 
-        We check that the ``args`` passed to the mutable ``arguments`` are mutable,
-        and that ``None`` is passed only to the optional ``arguments``.
+        The lists and the sets are invariant in their items, see
+        :py:func:`_assignable`, as the targets represent them with invariant types.
+        The only exception is a read-only ``Sequence[...]`` argument of
+        a verification function, which also accepts a list of the descendants of
+        its items, as the targets declare it generic, see
+        :py:func:`aas_core_codegen.intermediate.generic_sequence_item_class`.
+        The methods can not have generic arguments, since Go methods can not have
+        type parameters, and C++ virtual methods can not be templates.
 
-        The ``what`` describes the called function or method in the error messages,
-        *e.g.*, ``the verification function 'foo'``.
+        We further check that ``None`` is passed only to the optional arguments, and
+        that the ``args`` passed to the mutable arguments are mutable.
 
         :return: True if the check passed
         """
+        what = (
+            f"the verification function {callee.name!r}"
+            if isinstance(callee, _types.Verification)
+            else f"the method {callee.name!r}"
+        )
+
         ok = True
-        for arg_node, argument in zip(args, arguments):
+        for arg_node, argument in zip(args, callee.arguments):
             # NOTE (mristin):
             # We do not check the types of the arguments in general. However, we
-            # have to check the sets, since the targets represent them with
-            # different types which only the checks here make compatible.
+            # have to check the lists and the sets, see the docstring.
             arg_type = self.type_map.get(arg_node, None)
             argument_type = convert_type_annotation(argument.type_annotation)
+
+            accepts_descendants = (
+                isinstance(callee, _types.Verification)
+                and not argument.mutable
+                and arg_type is not None
+                and _is_list_of_descendants(
+                    target_type=argument_type, value_type=arg_type
+                )
+            )
+
             if (
                 arg_type is not None
-                and (_holds_set(arg_type) or _holds_set(argument_type))
+                and (_holds_list_or_set(arg_type) or _holds_list_or_set(argument_type))
                 and not _assignable(target_type=argument_type, value_type=arg_type)
+                and not accepts_descendants
             ):
                 self.errors.append(
                     Error(
                         arg_node.original_node,
                         f"The argument {argument.name!r} of {what} is "
-                        f"of type {argument_type}, but got: {arg_type}",
+                        f"of type {argument_type}, but got: {arg_type}. "
+                        f"The lists and the sets are invariant, so their items "
+                        f"need to be of exactly the same type. A mutable "
+                        f"List[...] can not hold the instances of a subclass, "
+                        f"since the callee could insert an instance of another "
+                        f"subclass into it. Only a read-only Sequence[...] "
+                        f"argument of a verification function accepts "
+                        f"the instances of a subclass, since the targets with "
+                        f"invariant lists declare it generic: Go with a type "
+                        f"parameter, C++ with a template, C# with IReadOnlyList<T> "
+                        f"and Java with List<? extends T>. The methods can not "
+                        f"accept them, since Go methods can not have type "
+                        f"parameters, and C++ virtual methods can not be "
+                        f"templates. We do not copy the list implicitly either, as "
+                        f"that would cost linear time and memory on each call. "
+                        f"Please declare the argument with the exact type of "
+                        f"the items.",
                     )
                 )
                 ok = False
@@ -4471,11 +4532,7 @@ def transform_method_call(
             )
             return None
 
-        if not self._check_arguments(
-            args=node.args,
-            arguments=member_type.method.arguments,
-            what=f"the method {node.member.name!r}",
-        ):
+        if not self._check_call_arguments(args=node.args, callee=member_type.method):
             return None
 
         if not member_type.method.non_mutating:
@@ -4634,11 +4691,7 @@ def transform_function_call(
 
         if isinstance(
             func_type, VerificationTypeAnnotation
-        ) and not self._check_arguments(
-            args=node.args,
-            arguments=func_type.func.arguments,
-            what=f"the verification function {func_type.func.name!r}",
-        ):
+        ) and not self._check_call_arguments(args=node.args, callee=func_type.func):
             return None
 
         # NOTE (mristin):
@@ -6052,6 +6105,20 @@ def transform_assignment(
         # and the type of the assigned value otherwise.
         variable_type = target_type if target_type is not None else value_type
 
+        # NOTE (mristin):
+        # An immutable alias of a variable of the very same type shares the type
+        # annotation of the variable. This way, the transpilers can tell by
+        # the identity of the type annotation that the alias holds a generic
+        # sequence, see :py:func:`_types.generic_sequence_item_class`.
+        if (
+            is_new_variable
+            and is_final
+            and isinstance(node.value, parse_tree.Name)
+            and target_type is not None
+            and _type_annotations_equal(target_type, value_type)
+        ):
+            variable_type = value_type
+
         if is_new_variable:
             assert isinstance(node.target, parse_tree.Name)
             if node.target.identifier in self._types_of_variables_in_closed_scopes[-1]:
@@ -7629,6 +7696,117 @@ def is_appended_list(node: parse_tree.Node) -> bool:
     return errors
 
 
+def _check_usages_of_generic_sequences(
+    body: Sequence[parse_tree.Node],
+    arguments: Sequence[_types.Argument],
+    type_map: Mapping[parse_tree.Node, "TypeAnnotationUnion"],
+) -> List[Error]:
+    """
+    Check that the generic sequences in the ``body`` are used only where we can
+    transpile them.
+
+    The ``arguments`` belong to a verification function. A generic sequence,
+    see :py:func:`aas_core_codegen.intermediate.generic_sequence_item_class`,
+    accepts the sequences of the descendants. The targets with invariant lists
+    declare it generic: Go with a type parameter, C++ with a template, C# with
+    ``IReadOnlyList<T>``, and Java with ``List<? extends T>``. Such an argument
+    can be only the collection of a for-loop or of ``all``/``any``, the collection
+    of an index, the container of ``in``, the argument of ``len``, the value of
+    a nullness check, an argument of a verification function, which is generic
+    as well, and the value of an immutable alias, *e.g.*,
+    ``alias: Final[Sequence[Item]] = items``, which is generic as well. Elsewhere,
+    *e.g.*, passed to a method or assigned to a variable, the targets would expect
+    the non-generic list, and we would have to copy it.
+    """
+    generic_name_set = {
+        argument.name
+        for argument in arguments
+        if _types.generic_sequence_item_class(argument) is not None
+    }
+
+    if len(generic_name_set) == 0:
+        return []
+
+    allowed_set = set()  # type: Set[parse_tree.Node]
+    generic_names = []  # type: List[parse_tree.Name]
+
+    for node_in_body in body:
+        for node in parse_tree.over_nodes(node_in_body):
+            if (
+                isinstance(node, parse_tree.Name)
+                and node.identifier in generic_name_set
+            ):
+                generic_names.append(node)
+
+            # NOTE (mristin):
+            # An immutable alias of a generic sequence is a generic sequence itself,
+            # since it shares the type annotation of the aliased variable, see
+            # :py:meth:`_Inferrer.transform_assignment`. The targets declare
+            # the alias with the type parameter.
+            if (
+                isinstance(node, parse_tree.Assignment)
+                and node.annotation is not None
+                and is_final_annotation(node.annotation)
+                and isinstance(node.target, parse_tree.Name)
+                and isinstance(node.value, parse_tree.Name)
+                and node.value.identifier in generic_name_set
+                and type_map.get(node.target, None) is type_map.get(node.value, None)
+            ):
+                allowed_set.add(node.target)
+                allowed_set.add(node.value)
+                generic_name_set.add(node.target.identifier)
+
+            if isinstance(node, parse_tree.ForEach):
+                allowed_set.add(node.iteration)
+
+            elif isinstance(node, parse_tree.Index):
+                allowed_set.add(node.collection)
+
+            elif isinstance(node, parse_tree.IsIn):
+                allowed_set.add(node.container)
+
+            elif isinstance(node, (parse_tree.IsNone, parse_tree.IsNotNone)):
+                allowed_set.add(node.value)
+
+            elif isinstance(node, parse_tree.FunctionCall):
+                func_type = type_map.get(node.name, None)
+
+                if isinstance(func_type, VerificationTypeAnnotation):
+                    allowed_set.update(node.args)
+
+                elif (
+                    isinstance(func_type, BuiltinFunctionTypeAnnotation)
+                    and func_type.func.kind is BuiltinFunctionKind.LEN
+                ):
+                    allowed_set.update(node.args)
+
+                else:
+                    pass
+
+            else:
+                pass
+
+    return [
+        Error(
+            name.original_node,
+            f"The argument {name.identifier!r} is a read-only Sequence[...] of "
+            f"a class with descendants, so the targets declare it generic to "
+            f"accept the sequences of the descendants without a copy: Go with "
+            f"a type parameter, C++ with a template, C# with IReadOnlyList<T>, "
+            f"and Java with List<? extends T>. Hence, we support it only as "
+            f"the collection of a for-loop or of all/any, the collection of "
+            f"an index, the container of in, the argument of len, the value of "
+            f"a nullness check, an argument of a verification function, and "
+            f"the value of an immutable alias of the very same type, *e.g.*, "
+            f"``alias: Final[Sequence[...]] = {name.identifier}``. Elsewhere, "
+            f"*e.g.*, passed to a method, assigned to a mutable variable or copied "
+            f"with list, the targets would expect the non-generic list.",
+        )
+        for name in generic_names
+        if name not in allowed_set
+    ]
+
+
 @ensure(lambda result: (result[0] is not None) ^ (result[1] is not None))
 def _infer_for_function(
     body: Sequence[parse_tree.Node],
@@ -7678,6 +7856,16 @@ def _infer_for_function(
         )
     )
 
+    # NOTE (mristin):
+    # Only the verification functions have generic arguments, as the methods can
+    # not be generic, see :py:func:`_types.generic_sequence_item_class`.
+    if enclosing_method is None:
+        type_inferrer.errors.extend(
+            _check_usages_of_generic_sequences(
+                body=body, arguments=arguments, type_map=type_inferrer.type_map
+            )
+        )
+
     # NOTE (mristin):
     # Some targets, such as Go or Java, refuse to compile a function which misses
     # a return statement at the end, so we refuse it here already.
diff --git a/aas_core_codegen/java/lib/_generate_verification.py b/aas_core_codegen/java/lib/_generate_verification.py
index 713d3a058..bd6a540cc 100644
--- a/aas_core_codegen/java/lib/_generate_verification.py
+++ b/aas_core_codegen/java/lib/_generate_verification.py
@@ -516,11 +516,45 @@ def _transpile_transpilable_verification(
         assert stmt is not None
         body.append(stmt)
 
+    # NOTE (mristin):
+    # The ``List<T>`` is invariant in Java, so we declare the generic sequences,
+    # see :py:func:`intermediate.generic_sequence_item_class`, with the wildcard
+    # ``List<? extends T>``. This way, the lists of the descendants can be passed
+    # without a copy. The ``Optional<T>`` is invariant as well, so we declare
+    # the optional generic sequences as ``Optional<? extends List<? extends T>>``.
+    arg_defs = []  # type: List[Stripped]
+    remarks_on_generic_sequences = []  # type: List[str]
+    for arg in verification.arguments:
+        arg_name = java_naming.argument_name(arg.name)
+
+        if intermediate.generic_sequence_item_class(arg) is None:
+            arg_type = java_common.generate_type(arg.type_annotation)
+        else:
+            list_type_anno = intermediate.beneath_optional(arg.type_annotation)
+            assert isinstance(list_type_anno, intermediate.ListTypeAnnotation)
+
+            item_type = java_common.generate_type(list_type_anno.items)
+
+            arg_type = Stripped(f"List<? extends {item_type}>")
+            if isinstance(arg.type_annotation, intermediate.OptionalTypeAnnotation):
+                arg_type = Stripped(f"Optional<? extends {arg_type}>")
+
+            remarks_on_generic_sequences.append(
+                f"The argument {{@code {arg_name}}} is declared with the wildcard "
+                f"{{@code List<? extends {item_type}>}} instead of the invariant "
+                f"{{@code List<{item_type}>}} so that the lists of "
+                f"the descendants of {{@link {item_type}}} can be passed without "
+                f"a copy."
+            )
+
+        arg_defs.append(Stripped(f"{arg_type} {arg_name}"))
+
     writer = io.StringIO()
     if verification.description is not None:
         comment, comment_errors = java_description.generate_comment_for_signature(
             description=verification.description,
             context=java_description.Context(package=package, cls_or_enum=None),
+            extra_remarks=remarks_on_generic_sequences,
         )
         if comment_errors is not None:
             return None, Error(
@@ -533,6 +567,15 @@ def _transpile_transpilable_verification(
 
         writer.write(comment)
         writer.write("\n")
+    elif len(remarks_on_generic_sequences) > 0:
+        writer.write(
+            java_description.documentation_comment(
+                Stripped("\n\n".join(remarks_on_generic_sequences))
+            )
+        )
+        writer.write("\n")
+    else:
+        pass
 
     method_name = java_naming.method_name(verification.name)
 
@@ -550,12 +593,6 @@ def _transpile_transpilable_verification(
     else:
         return_type = java_common.generate_type(type_annotation=verification.returns)
 
-    arg_defs = []  # type: List[Stripped]
-    for arg in verification.arguments:
-        arg_type = java_common.generate_type(arg.type_annotation)
-        arg_name = java_naming.argument_name(arg.name)
-        arg_defs.append(Stripped(f"{arg_type} {arg_name}"))
-
     if len(arg_defs) == 0:
         writer.write(
             f"""\
diff --git a/aas_core_codegen/java/transpilation.py b/aas_core_codegen/java/transpilation.py
index bb284ac6c..d99639196 100644
--- a/aas_core_codegen/java/transpilation.py
+++ b/aas_core_codegen/java/transpilation.py
@@ -2096,6 +2096,20 @@ def transform_assignment(
                 target, error = self.transform_name(node=node.target)
                 if error is not None:
                     errors.append(error)
+                elif (
+                    node.annotation is not None
+                    and isinstance(node.value, parse_tree.Name)
+                    and self.type_map[node.target] is self.type_map[node.value]
+                ):
+                    # NOTE (mristin):
+                    # An immutable alias shares the type annotation of the aliased
+                    # variable, see
+                    # :py:meth:`intermediate_type_inference._Inferrer.transform_assignment`,
+                    # so we infer its type with ``var``. This way, the alias of
+                    # a generic sequence is also declared with the wildcard
+                    # ``List<? extends T>``, see
+                    # :py:func:`intermediate.generic_sequence_item_class`.
+                    target = Stripped(f"var {target}")
                 elif node.annotation is not None and (
                     intermediate_type_inference.try_primitive_type(type_anno)
                     is not intermediate_type_inference.PrimitiveType.INT
diff --git a/dev/test_data/common_meta_models/variance_of_containers.py b/dev/test_data/common_meta_models/variance_of_containers.py
new file mode 100644
index 000000000..99274c58c
--- /dev/null
+++ b/dev/test_data/common_meta_models/variance_of_containers.py
@@ -0,0 +1,407 @@
+"""
+Test the variance of the containers passed as arguments.
+
+A read-only ``Sequence[...]`` argument of a verification function is generic if its
+items are instances of a class with descendants, so that the sequences of
+the descendants can be passed to it without a copy. The arguments of the methods
+and the mutable ``List[...]`` arguments remain invariant.
+"""
+
+from typing import Final, List, Optional, Sequence, Set
+
+from icontract import DBC, invariant
+
+
+@abstract
+@serialization(with_model_type=True)
+class Item(DBC):
+    name: str
+
+    # NOTE (mristin):
+    # The optional property mirrors ``Referable.ID_short`` in aas-core-meta V3.2,
+    # see :func:`nicknames_are_unique`.
+    nickname: Optional[str]
+
+    def __init__(self, name: str, nickname: Optional[str] = None) -> None:
+        self.name = name
+        self.nickname = nickname
+
+
+class Some_item(Item, DBC):
+    def __init__(self, name: str, nickname: Optional[str] = None) -> None:
+        Item.__init__(self, name, nickname)
+
+
+class Special_item(Some_item, DBC):
+    level: int
+
+    def __init__(self, name: str, level: int, nickname: Optional[str] = None) -> None:
+        Some_item.__init__(self, name, nickname)
+        self.level = level
+
+
+@verification
+def names_are_unique(items: Sequence[Item]) -> bool:
+    """
+    Check that the names of the :paramref:`items` are unique.
+
+    The :paramref:`items` are a generic sequence, so the sequences of
+    the descendants of :class:`Item` can be passed without a copy.
+    """
+    name_set: Set[str] = set()
+    for item in items:
+        if item.name in name_set:
+            return False
+
+        name_set.add(item.name)
+
+    return True
+
+
+@verification
+def names_are_non_empty(items: Sequence[Item]) -> bool:
+    """Iterate over a generic sequence in a generator."""
+    return all(len(item.name) > 0 for item in items)
+
+
+@verification
+def some_special_item_has_level(items: Sequence[Item]) -> bool:
+    """Narrow the items of a generic sequence in a generator."""
+    return any(isinstance(item, Special_item) and item.level > 0 for item in items)
+
+
+@verification
+def first_is_special(items: Sequence[Item]) -> bool:
+    """Index a generic sequence, and narrow the item."""
+    if len(items) == 0:
+        return False
+
+    first = items[0]
+    if isinstance(first, Special_item):
+        return first.level > 0
+
+    return False
+
+
+@verification
+def nicknames_are_unique(items: Sequence[Item]) -> bool:
+    """
+    Check that the nicknames of the :paramref:`items` are unique, if specified.
+
+    This mirrors the body of ``ID_shorts_are_unique`` in aas-core-meta V3.2:
+    a local variable takes an optional property of an item of a generic sequence,
+    and the loop continues if it is None.
+    """
+    nickname_set: Set[str] = set()
+    for item in items:
+        nickname = item.nickname
+        if nickname is None:
+            continue
+
+        if nickname in nickname_set:
+            return False
+
+        nickname_set.add(nickname)
+
+    return True
+
+
+@verification
+def levels_of_special_items_are_positive(items: Sequence[Item]) -> bool:
+    """
+    Narrow the loop variable over a generic sequence in a for-loop.
+
+    The loop variable is of the type parameter in Go, so the down-cast needs to
+    go through ``any(...)``, and of the template parameter in C++.
+    """
+    for item in items:
+        if isinstance(item, Special_item):
+            if item.level <= 0:
+                return False
+
+    return True
+
+
+@verification
+def last_is_special(items: Sequence[Item]) -> bool:
+    """
+    Narrow an immutable local variable which holds an item of a generic sequence.
+
+    In contrast to :func:`first_is_special`, the local variable is annotated, so
+    it is of the parent class instead of the type parameter. Hence, Go down-casts
+    it without ``any(...)``, and C++ binds the item to a constant reference to
+    the shared pointer of the parent class.
+    """
+    if len(items) == 0:
+        return False
+
+    last: Final[Item] = items[len(items) - 1]
+    if isinstance(last, Special_item):
+        return last.level > 0
+
+    return False
+
+
+@verification
+def names_are_disjoint(
+    items: Sequence[Item], other_items: Sequence[Some_item], shared_name: str
+) -> bool:
+    """
+    Mix two generic sequences with an argument which is not generic.
+
+    The names must differ, except for the :paramref:`shared_name`, which may repeat.
+
+    Go declares two type parameters, and C++ two template parameters. The nested
+    generators iterate over two different generic sequences, so their variables
+    are of two different type parameters.
+    """
+    return all(
+        all(
+            item.name != other_item.name or item.name == shared_name
+            for other_item in other_items
+        )
+        for item in items
+    )
+
+
+@verification
+def aliased_names_are_unique(
+    items: Sequence[Item], optional_items: Optional[Sequence[Item]]
+) -> bool:
+    """
+    Use the immutable aliases of the generic sequences.
+
+    An immutable alias of the very same type shares the type annotation of
+    the aliased generic sequence, so it is a generic sequence itself. Go declares
+    the alias with the type parameter, C++ with the template parameter, while C#
+    and Java infer its type with ``var``. The ``alias_of_alias`` aliases an alias,
+    and the ``optional_alias`` aliases an optional generic sequence.
+    """
+    alias: Final[Sequence[Item]] = items
+    alias_of_alias: Final[Sequence[Item]] = alias
+    optional_alias: Final[Optional[Sequence[Item]]] = optional_items
+
+    for item in alias:
+        if isinstance(item, Special_item):
+            if item.level <= 0:
+                return False
+
+    return (
+        all(len(item.name) > 0 for item in alias_of_alias)
+        and names_are_unique(alias_of_alias)
+        and optional_names_are_unique(optional_alias)
+        and (optional_alias is None or names_are_unique(optional_alias))
+    )
+
+
+@verification
+def contains_some_item(some_item: Some_item, items: Sequence[Item]) -> bool:
+    """
+    Look up an instance of a descendant in a generic sequence.
+
+    Go compares the instances as ``any``'s, as the items are of the type parameter,
+    and C++ converts the member to the shared pointer of :class:`Item` so that
+    the raw pointers are comparable for any template parameter.
+    """
+    return some_item in items
+
+
+@verification
+def items_overlap(items: Sequence[Item], other_items: Sequence[Some_item]) -> bool:
+    """
+    Look up the items of a generic sequence in another generic sequence.
+
+    The member and the items are of two different type parameters.
+    """
+    return any(other_item in items for other_item in other_items)
+
+
+@verification
+def contains_special_item(
+    special_item: Special_item, items: Sequence[Special_item]
+) -> bool:
+    """
+    Look up an instance in a sequence which is not generic.
+
+    The :class:`Special_item` has no descendants, so the :paramref:`items` are not
+    a generic sequence, but Go still compares the instances as ``any``'s.
+    """
+    return special_item in items
+
+
+@verification
+def container_names_are_unique(container: "Container") -> bool:
+    """
+    Pass the local variables on to generic sequences.
+
+    The ``some_items`` is a read-only alias without an annotation, while
+    the ``all_some_items`` is an immutable local variable declared with
+    ``Final[...]``. Both hold the sequences of :class:`Some_item`, and are passed
+    on to the generic sequences of :class:`Item`, required as well as optional.
+    """
+    some_items = container.some_items
+    all_some_items: Final[Sequence[Some_item]] = container.some_items
+    return (
+        names_are_unique(some_items)
+        and names_are_unique(all_some_items)
+        and optional_names_are_unique(all_some_items)
+    )
+
+
+@verification
+def optional_names_are_unique(items: Optional[Sequence[Item]]) -> bool:
+    """Pass an optional generic sequence on to a generic sequence."""
+    return items is None or names_are_unique(items)
+
+
+@verification
+def some_names_are_unique(
+    some_items: Sequence[Some_item], special_items: Optional[Sequence[Special_item]]
+) -> bool:
+    """
+    Pass the generic sequences of the descendants on.
+
+    The :paramref:`some_items` are passed on as a required and as an optional
+    sequence of the parent class, while the :paramref:`special_items` are passed on
+    as an optional sequence and, once narrowed, as a required sequence of the parent
+    class of the parent class.
+    """
+    return (
+        names_are_unique(some_items)
+        and optional_names_are_unique(some_items)
+        and optional_names_are_unique(special_items)
+        and optional_names_are_unique(None)
+        and (special_items is None or names_are_unique(special_items))
+    )
+
+
+@verification
+def levels_are_positive(items: Sequence[Special_item]) -> bool:
+    """
+    Check that the levels are positive.
+
+    The :class:`Special_item` has no descendants, so the :paramref:`items` are not
+    a generic sequence.
+    """
+    return all(item.level > 0 for item in items)
+
+
+@invariant(
+    lambda self: names_are_unique(self.items),
+    "Names of the items must be unique.",
+)
+@invariant(
+    lambda self: some_names_are_unique(self.some_items, self.special_items),
+    "Names of some items and of special items must be unique.",
+)
+@invariant(
+    lambda self: names_are_non_empty(self.some_items),
+    "Names of some items must be non-empty.",
+)
+@invariant(
+    lambda self: not some_special_item_has_level(self.items)
+    or first_is_special(self.items),
+    "If there is a special item with level, the first item must be special.",
+)
+@invariant(
+    lambda self: not (self.special_items is not None)
+    or levels_are_positive(self.special_items),
+    "Levels of the special items must be positive.",
+)
+@invariant(
+    lambda self: not (self.special_items is not None)
+    or first_is_special(self.special_items),
+    "The first special item must be special.",
+)
+@invariant(
+    lambda self: optional_names_are_unique(self.special_items),
+    "Names of the special items must be unique.",
+)
+@invariant(
+    lambda self: self.count_items(self.items) == len(self.items),
+    "Count of the items must match the number of the items.",
+)
+@invariant(
+    lambda self: nicknames_are_unique(self.some_items),
+    "Nicknames of some items must be unique.",
+)
+@invariant(
+    lambda self: levels_of_special_items_are_positive(self.items),
+    "Levels of the special items among the items must be positive.",
+)
+@invariant(
+    lambda self: not some_special_item_has_level(self.items)
+    or last_is_special(self.items),
+    "If there is a special item with level, the last item must be special.",
+)
+@invariant(
+    lambda self: names_are_disjoint(self.items, self.some_items, "x"),
+    "Names of the items and of some items must be disjoint.",
+)
+@invariant(
+    lambda self: aliased_names_are_unique(self.some_items, self.special_items),
+    "Names of some items and of special items must be unique through aliases.",
+)
+@invariant(
+    lambda self: all(
+        contains_some_item(some_item, self.items) for some_item in self.some_items
+    ),
+    "Some items must be among the items.",
+)
+@invariant(
+    lambda self: len(self.some_items) == 0
+    or items_overlap(self.items, self.some_items),
+    "If there are some items, they must overlap with the items.",
+)
+@invariant(
+    lambda self: not (self.special_items is not None)
+    or all(
+        contains_special_item(special_item, self.special_items)
+        for special_item in self.special_items
+    ),
+    "Each special item must be among the special items.",
+)
+class Container(DBC):
+    items: List[Item]
+    some_items: List[Some_item]
+    special_items: Optional[List[Special_item]]
+
+    @non_mutating
+    def count_items(self, items: Sequence[Item]) -> int:
+        """
+        Count the :paramref:`items`.
+
+        The arguments of the methods are never generic, so only the sequences of
+        :class:`Item` can be passed to it, but not the sequences of
+        the descendants.
+        """
+        return len(items)
+
+    def __init__(
+        self,
+        items: List[Item],
+        some_items: List[Some_item],
+        special_items: Optional[List[Special_item]] = None,
+    ) -> None:
+        self.items = items
+        self.some_items = some_items
+        self.special_items = special_items
+
+
+# NOTE (mristin):
+# We pass the container as a property, since the C++ invariants hold ``self`` as
+# a raw pointer, which can not be passed on to a verification function expecting
+# a shared pointer.
+@invariant(
+    lambda self: container_names_are_unique(self.container),
+    "Names of some items of the container must be unique.",
+)
+class Wrapper(DBC):
+    container: Container
+
+    def __init__(self, container: Container) -> None:
+        self.container = container
+
+
+__version__ = "dummy"
+__xml_namespace__ = "https://dummy.com"
diff --git a/dev/test_data/intermediate/common_meta_models/variance_of_containers/expected_symbol_table.txt b/dev/test_data/intermediate/common_meta_models/variance_of_containers/expected_symbol_table.txt
new file mode 100644
index 000000000..577aed1c6
--- /dev/null
+++ b/dev/test_data/intermediate/common_meta_models/variance_of_containers/expected_symbol_table.txt
@@ -0,0 +1,1637 @@
+SymbolTable(
+  our_types=[
+    AbstractClass(
+      name='Item',
+      inheritances=[],
+      inheritance_id_set=...,
+      ancestors=[],
+      ancestor_id_set=...,
+      interface=Interface(
+        base='Reference to AbstractClass Item',
+        name='Item',
+        inheritances=[],
+        implementers=[
+          'Reference to ConcreteClass Some_item',
+          'Reference to ConcreteClass Special_item'],
+        properties=[
+          Property(
+            name='name',
+            type_annotation=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            description=None,
+            specified_for='Reference to AbstractClass Item',
+            json_name='name',
+            xml_name='name',
+            parsed=...),
+          Property(
+            name='nickname',
+            type_annotation=OptionalTypeAnnotation(
+              value=PrimitiveTypeAnnotation(
+                a_type='STR',
+                parsed=...),
+              parsed=...),
+            description=None,
+            specified_for='Reference to AbstractClass Item',
+            json_name='nickname',
+            xml_name='nickname',
+            parsed=...)],
+        signatures=[],
+        description=None,
+        parsed=...,
+        properties_by_name=...,
+        property_id_set=...),
+      descendant_id_set=...,
+      descendants=[
+        'Reference to ConcreteClass Some_item',
+        'Reference to ConcreteClass Special_item'],
+      concrete_descendant_id_set=...,
+      concrete_descendants=[
+        'Reference to ConcreteClass Some_item',
+        'Reference to ConcreteClass Special_item'],
+      properties=[
+        Property(
+          name='name',
+          type_annotation=PrimitiveTypeAnnotation(
+            a_type='STR',
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='name',
+          xml_name='name',
+          parsed=...),
+        Property(
+          name='nickname',
+          type_annotation=OptionalTypeAnnotation(
+            value=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='nickname',
+          xml_name='nickname',
+          parsed=...)],
+      methods=[],
+      constructor=Constructor(
+        name='__init__',
+        arguments=[
+          Argument(
+            name='name',
+            type_annotation=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            default=None,
+            mutable=False,
+            parsed=...),
+          Argument(
+            name='nickname',
+            type_annotation=OptionalTypeAnnotation(
+              value=PrimitiveTypeAnnotation(
+                a_type='STR',
+                parsed=...),
+              parsed=...),
+            default=DefaultPrimitive(
+              value=None,
+              parsed=...),
+            mutable=False,
+            parsed=...)],
+        returns=None,
+        description=None,
+        contracts=Contracts(
+          preconditions=[],
+          snapshots=[],
+          postconditions=[]),
+        parsed=...,
+        arguments_by_name=...,
+        statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='name',
+              argument='name',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='nickname',
+              argument='nickname',
+              default=None)""")],
+        inlined_statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='name',
+              argument='name',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='nickname',
+              argument='nickname',
+              default=None)""")]),
+      invariants=[],
+      serialization=Serialization(
+        with_model_type=True),
+      description=None,
+      parsed=...,
+      properties_by_name=...,
+      property_id_set=...,
+      methods_by_name=...,
+      method_id_set=...,
+      invariant_id_set=...),
+    ConcreteClass(
+      name='Some_item',
+      inheritances=[
+        'Reference to AbstractClass Item'],
+      inheritance_id_set=...,
+      ancestors=[
+        'Reference to AbstractClass Item'],
+      ancestor_id_set=...,
+      interface=Interface(
+        base='Reference to ConcreteClass Some_item',
+        name='Some_item',
+        inheritances=[
+          'Reference to Interface Item'],
+        implementers=[
+          'Reference to ConcreteClass Special_item',
+          'Reference to ConcreteClass Some_item'],
+        properties=[],
+        signatures=[],
+        description=None,
+        parsed=...,
+        properties_by_name=...,
+        property_id_set=...),
+      descendant_id_set=...,
+      descendants=[
+        'Reference to ConcreteClass Special_item'],
+      concrete_descendant_id_set=...,
+      concrete_descendants=[
+        'Reference to ConcreteClass Special_item'],
+      properties=[
+        Property(
+          name='name',
+          type_annotation=PrimitiveTypeAnnotation(
+            a_type='STR',
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='name',
+          xml_name='name',
+          parsed=...),
+        Property(
+          name='nickname',
+          type_annotation=OptionalTypeAnnotation(
+            value=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='nickname',
+          xml_name='nickname',
+          parsed=...)],
+      methods=[],
+      constructor=Constructor(
+        name='__init__',
+        arguments=[
+          Argument(
+            name='name',
+            type_annotation=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            default=None,
+            mutable=False,
+            parsed=...),
+          Argument(
+            name='nickname',
+            type_annotation=OptionalTypeAnnotation(
+              value=PrimitiveTypeAnnotation(
+                a_type='STR',
+                parsed=...),
+              parsed=...),
+            default=DefaultPrimitive(
+              value=None,
+              parsed=...),
+            mutable=False,
+            parsed=...)],
+        returns=None,
+        description=None,
+        contracts=Contracts(
+          preconditions=[],
+          snapshots=[],
+          postconditions=[]),
+        parsed=...,
+        arguments_by_name=...,
+        statements=[
+          textwrap.dedent("""\
+            CallSuperConstructor(
+              super_name='Item')""")],
+        inlined_statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='name',
+              argument='name',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='nickname',
+              argument='nickname',
+              default=None)""")]),
+      invariants=[],
+      serialization=Serialization(
+        with_model_type=True),
+      description=None,
+      parsed=...,
+      properties_by_name=...,
+      property_id_set=...,
+      methods_by_name=...,
+      method_id_set=...,
+      invariant_id_set=...),
+    ConcreteClass(
+      name='Special_item',
+      inheritances=[
+        'Reference to ConcreteClass Some_item'],
+      inheritance_id_set=...,
+      ancestors=[
+        'Reference to AbstractClass Item',
+        'Reference to ConcreteClass Some_item'],
+      ancestor_id_set=...,
+      interface=None,
+      descendant_id_set=...,
+      descendants=[],
+      concrete_descendant_id_set=...,
+      concrete_descendants=[],
+      properties=[
+        Property(
+          name='name',
+          type_annotation=PrimitiveTypeAnnotation(
+            a_type='STR',
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='name',
+          xml_name='name',
+          parsed=...),
+        Property(
+          name='nickname',
+          type_annotation=OptionalTypeAnnotation(
+            value=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to AbstractClass Item',
+          json_name='nickname',
+          xml_name='nickname',
+          parsed=...),
+        Property(
+          name='level',
+          type_annotation=PrimitiveTypeAnnotation(
+            a_type='INT',
+            parsed=...),
+          description=None,
+          specified_for='Reference to ConcreteClass Special_item',
+          json_name='level',
+          xml_name='level',
+          parsed=...)],
+      methods=[],
+      constructor=Constructor(
+        name='__init__',
+        arguments=[
+          Argument(
+            name='name',
+            type_annotation=PrimitiveTypeAnnotation(
+              a_type='STR',
+              parsed=...),
+            default=None,
+            mutable=False,
+            parsed=...),
+          Argument(
+            name='level',
+            type_annotation=PrimitiveTypeAnnotation(
+              a_type='INT',
+              parsed=...),
+            default=None,
+            mutable=False,
+            parsed=...),
+          Argument(
+            name='nickname',
+            type_annotation=OptionalTypeAnnotation(
+              value=PrimitiveTypeAnnotation(
+                a_type='STR',
+                parsed=...),
+              parsed=...),
+            default=DefaultPrimitive(
+              value=None,
+              parsed=...),
+            mutable=False,
+            parsed=...)],
+        returns=None,
+        description=None,
+        contracts=Contracts(
+          preconditions=[],
+          snapshots=[],
+          postconditions=[]),
+        parsed=...,
+        arguments_by_name=...,
+        statements=[
+          textwrap.dedent("""\
+            CallSuperConstructor(
+              super_name='Some_item')"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='level',
+              argument='level',
+              default=None)""")],
+        inlined_statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='name',
+              argument='name',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='nickname',
+              argument='nickname',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='level',
+              argument='level',
+              default=None)""")]),
+      invariants=[],
+      serialization=Serialization(
+        with_model_type=True),
+      description=None,
+      parsed=...,
+      properties_by_name=...,
+      property_id_set=...,
+      methods_by_name=...,
+      method_id_set=...,
+      invariant_id_set=...),
+    ConcreteClass(
+      name='Container',
+      inheritances=[],
+      inheritance_id_set=...,
+      ancestors=[],
+      ancestor_id_set=...,
+      interface=None,
+      descendant_id_set=...,
+      descendants=[],
+      concrete_descendant_id_set=...,
+      concrete_descendants=[],
+      properties=[
+        Property(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to ConcreteClass Container',
+          json_name='items',
+          xml_name='items',
+          parsed=...),
+        Property(
+          name='some_items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Some_item',
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to ConcreteClass Container',
+          json_name='someItems',
+          xml_name='someItems',
+          parsed=...),
+        Property(
+          name='special_items',
+          type_annotation=OptionalTypeAnnotation(
+            value=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Special_item',
+                parsed=...),
+              parsed=...),
+            parsed=...),
+          description=None,
+          specified_for='Reference to ConcreteClass Container',
+          json_name='specialItems',
+          xml_name='specialItems',
+          parsed=...)],
+      methods=[
+        UnderstoodMethod(
+          name='count_items',
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='items',
+              type_annotation=ListTypeAnnotation(
+                items=OurTypeAnnotation(
+                  our_type='Reference to our type Item',
+                  parsed=...),
+                parsed=...),
+              default=None,
+              mutable=False,
+              parsed=...)],
+          returns=PrimitiveTypeAnnotation(
+            a_type='INT',
+            parsed=...),
+          description=DescriptionOfSignature(
+            summary='<paragraph>Count the <ReferenceToArgument refuri="items">items</ReferenceToArgument>.</paragraph>',
+            remarks=[
+              textwrap.dedent("""\
+                <paragraph>The arguments of the methods are never generic, so only the sequences of
+                <ReferenceToOurType refuri="Item">Item</ReferenceToOurType> can be passed to it, but not the sequences of
+                the descendants.</paragraph>""")],
+            arguments_by_name=[],
+            returns=None,
+            parsed=...),
+          specified_for='Reference to ConcreteClass Container',
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=True,
+          parsed=...,
+          body=[
+            textwrap.dedent("""\
+              Return(
+                value=FunctionCall(
+                  name='len',
+                  args=[
+                    Name(
+                      identifier='items',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...)""")],
+          arguments_by_name=...)],
+      constructor=Constructor(
+        name='__init__',
+        arguments=[
+          Argument(
+            name='items',
+            type_annotation=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Item',
+                parsed=...),
+              parsed=...),
+            default=None,
+            mutable=True,
+            parsed=...),
+          Argument(
+            name='some_items',
+            type_annotation=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Some_item',
+                parsed=...),
+              parsed=...),
+            default=None,
+            mutable=True,
+            parsed=...),
+          Argument(
+            name='special_items',
+            type_annotation=OptionalTypeAnnotation(
+              value=ListTypeAnnotation(
+                items=OurTypeAnnotation(
+                  our_type='Reference to our type Special_item',
+                  parsed=...),
+                parsed=...),
+              parsed=...),
+            default=DefaultPrimitive(
+              value=None,
+              parsed=...),
+            mutable=True,
+            parsed=...)],
+        returns=None,
+        description=None,
+        contracts=Contracts(
+          preconditions=[],
+          snapshots=[],
+          postconditions=[]),
+        parsed=...,
+        arguments_by_name=...,
+        statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='items',
+              argument='items',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='some_items',
+              argument='some_items',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='special_items',
+              argument='special_items',
+              default=None)""")],
+        inlined_statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='items',
+              argument='items',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='some_items',
+              argument='some_items',
+              default=None)"""),
+          textwrap.dedent("""\
+            AssignArgument(
+              name='special_items',
+              argument='special_items',
+              default=None)""")]),
+      invariants=[
+        Invariant(
+          description='Each special item must be among the special items.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=All(
+                generator=ForEach(
+                  variable=Name(
+                    identifier='special_item',
+                    original_node=...),
+                  iteration=Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...),
+                  original_node=...),
+                condition=FunctionCall(
+                  name='contains_special_item',
+                  args=[
+                    Name(
+                      identifier='special_item',
+                      original_node=...),
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='special_items',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='If there are some items, they must overlap with the items.',
+          body=textwrap.dedent("""\
+            Or(
+              values=[
+                Comparison(
+                  left=FunctionCall(
+                    name='len',
+                    args=[
+                      Member(
+                        instance=Name(
+                          identifier='self',
+                          original_node=...),
+                        name='some_items',
+                        original_node=...)],
+                    original_node=...),
+                  op='EQ',
+                  right=Constant(
+                    value=0,
+                    original_node=...),
+                  original_node=...),
+                FunctionCall(
+                  name='items_overlap',
+                  args=[
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='items',
+                      original_node=...),
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='some_items',
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Some items must be among the items.',
+          body=textwrap.dedent("""\
+            All(
+              generator=ForEach(
+                variable=Name(
+                  identifier='some_item',
+                  original_node=...),
+                iteration=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                original_node=...),
+              condition=FunctionCall(
+                name='contains_some_item',
+                args=[
+                  Name(
+                    identifier='some_item',
+                    original_node=...),
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of some items and of special items must be unique through aliases.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='aliased_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of the items and of some items must be disjoint.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_disjoint',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Constant(
+                  value='x',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='If there is a special item with level, the last item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=FunctionCall(
+                name='some_special_item_has_level',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              consequent=FunctionCall(
+                name='last_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Levels of the special items among the items must be positive.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='levels_of_special_items_are_positive',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Nicknames of some items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='nicknames_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Count of the items must match the number of the items.',
+          body=textwrap.dedent("""\
+            Comparison(
+              left=MethodCall(
+                member=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='count_items',
+                  original_node=...),
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              op='EQ',
+              right=FunctionCall(
+                name='len',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of the special items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='optional_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='The first special item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=FunctionCall(
+                name='first_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Levels of the special items must be positive.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=FunctionCall(
+                name='levels_are_positive',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='If there is a special item with level, the first item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=FunctionCall(
+                name='some_special_item_has_level',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              consequent=FunctionCall(
+                name='first_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of some items must be non-empty.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_non_empty',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of some items and of special items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='some_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...),
+        Invariant(
+          description='Names of the items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Container',
+          parsed=...)],
+      serialization=Serialization(
+        with_model_type=False),
+      description=None,
+      parsed=...,
+      properties_by_name=...,
+      property_id_set=...,
+      methods_by_name=...,
+      method_id_set=...,
+      invariant_id_set=...),
+    ConcreteClass(
+      name='Wrapper',
+      inheritances=[],
+      inheritance_id_set=...,
+      ancestors=[],
+      ancestor_id_set=...,
+      interface=None,
+      descendant_id_set=...,
+      descendants=[],
+      concrete_descendant_id_set=...,
+      concrete_descendants=[],
+      properties=[
+        Property(
+          name='container',
+          type_annotation=OurTypeAnnotation(
+            our_type='Reference to our type Container',
+            parsed=...),
+          description=None,
+          specified_for='Reference to ConcreteClass Wrapper',
+          json_name='container',
+          xml_name='container',
+          parsed=...)],
+      methods=[],
+      constructor=Constructor(
+        name='__init__',
+        arguments=[
+          Argument(
+            name='container',
+            type_annotation=OurTypeAnnotation(
+              our_type='Reference to our type Container',
+              parsed=...),
+            default=None,
+            mutable=False,
+            parsed=...)],
+        returns=None,
+        description=None,
+        contracts=Contracts(
+          preconditions=[],
+          snapshots=[],
+          postconditions=[]),
+        parsed=...,
+        arguments_by_name=...,
+        statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='container',
+              argument='container',
+              default=None)""")],
+        inlined_statements=[
+          textwrap.dedent("""\
+            AssignArgument(
+              name='container',
+              argument='container',
+              default=None)""")]),
+      invariants=[
+        Invariant(
+          description='Names of some items of the container must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='container_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='container',
+                  original_node=...)],
+              original_node=...)"""),
+          specified_for='Reference to ConcreteClass Wrapper',
+          parsed=...)],
+      serialization=Serialization(
+        with_model_type=False),
+      description=None,
+      parsed=...,
+      properties_by_name=...,
+      property_id_set=...,
+      methods_by_name=...,
+      method_id_set=...,
+      invariant_id_set=...)],
+  our_types_topologically_sorted=[
+    'Reference to our type Container',
+    'Reference to our type Item',
+    'Reference to our type Some_item',
+    'Reference to our type Special_item',
+    'Reference to our type Wrapper'],
+  enumerations=[],
+  constrained_primitives=[],
+  classes=[
+    'Reference to our type Item',
+    'Reference to our type Some_item',
+    'Reference to our type Special_item',
+    'Reference to our type Container',
+    'Reference to our type Wrapper'],
+  concrete_classes=[
+    'Reference to our type Some_item',
+    'Reference to our type Special_item',
+    'Reference to our type Container',
+    'Reference to our type Wrapper'],
+  named_unions=[],
+  constants=[],
+  constants_by_name=...,
+  verification_functions=[
+    TranspilableVerification(
+      name='names_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Check that the names of the <ReferenceToArgument refuri="items">items</ReferenceToArgument> are unique.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The <ReferenceToArgument refuri="items">items</ReferenceToArgument> are a generic sequence, so the sequences of
+            the descendants of <ReferenceToOurType refuri="Item">Item</ReferenceToOurType> can be passed without a copy.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='names_are_non_empty',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Iterate over a generic sequence in a generator.</paragraph>',
+        remarks=[],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='some_special_item_has_level',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Narrow the items of a generic sequence in a generator.</paragraph>',
+        remarks=[],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='first_is_special',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Index a generic sequence, and narrow the item.</paragraph>',
+        remarks=[],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='nicknames_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Check that the nicknames of the <ReferenceToArgument refuri="items">items</ReferenceToArgument> are unique, if specified.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>This mirrors the body of <literal>ID_shorts_are_unique</literal> in aas-core-meta V3.2:
+            a local variable takes an optional property of an item of a generic sequence,
+            and the loop continues if it is None.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='levels_of_special_items_are_positive',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Narrow the loop variable over a generic sequence in a for-loop.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The loop variable is of the type parameter in Go, so the down-cast needs to
+            go through <literal>any(...)</literal>, and of the template parameter in C++.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='last_is_special',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Narrow an immutable local variable which holds an item of a generic sequence.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>In contrast to <ReferenceToVerificationFunction refuri="first_is_special">first_is_special</ReferenceToVerificationFunction>, the local variable is annotated, so
+            it is of the parent class instead of the type parameter. Hence, Go down-casts
+            it without <literal>any(...)</literal>, and C++ binds the item to a constant reference to
+            the shared pointer of the parent class.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='names_are_disjoint',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='other_items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Some_item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='shared_name',
+          type_annotation=PrimitiveTypeAnnotation(
+            a_type='STR',
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Mix two generic sequences with an argument which is not generic.</paragraph>',
+        remarks=[
+          '<paragraph>The names must differ, except for the <ReferenceToArgument refuri="shared_name">shared_name</ReferenceToArgument>, which may repeat.</paragraph>',
+          textwrap.dedent("""\
+            <paragraph>Go declares two type parameters, and C++ two template parameters. The nested
+            generators iterate over two different generic sequences, so their variables
+            are of two different type parameters.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='aliased_names_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='optional_items',
+          type_annotation=OptionalTypeAnnotation(
+            value=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Item',
+                parsed=...),
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Use the immutable aliases of the generic sequences.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>An immutable alias of the very same type shares the type annotation of
+            the aliased generic sequence, so it is a generic sequence itself. Go declares
+            the alias with the type parameter, C++ with the template parameter, while C#
+            and Java infer its type with <literal>var</literal>. The <literal>alias_of_alias</literal> aliases an alias,
+            and the <literal>optional_alias</literal> aliases an optional generic sequence.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='contains_some_item',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='some_item',
+          type_annotation=OurTypeAnnotation(
+            our_type='Reference to our type Some_item',
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Look up an instance of a descendant in a generic sequence.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>Go compares the instances as <literal>any</literal>'s, as the items are of the type parameter,
+            and C++ converts the member to the shared pointer of <ReferenceToOurType refuri="Item">Item</ReferenceToOurType> so that
+            the raw pointers are comparable for any template parameter.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='items_overlap',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='other_items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Some_item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Look up the items of a generic sequence in another generic sequence.</paragraph>',
+        remarks=[
+          '<paragraph>The member and the items are of two different type parameters.</paragraph>'],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='contains_special_item',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='special_item',
+          type_annotation=OurTypeAnnotation(
+            our_type='Reference to our type Special_item',
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Special_item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Look up an instance in a sequence which is not generic.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The <ReferenceToOurType refuri="Special_item">Special_item</ReferenceToOurType> has no descendants, so the <ReferenceToArgument refuri="items">items</ReferenceToArgument> are not
+            a generic sequence, but Go still compares the instances as <literal>any</literal>'s.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='container_names_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='container',
+          type_annotation=OurTypeAnnotation(
+            our_type='Reference to our type Container',
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Pass the local variables on to generic sequences.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The <literal>some_items</literal> is a read-only alias without an annotation, while
+            the <literal>all_some_items</literal> is an immutable local variable declared with
+            <literal>Final[...]</literal>. Both hold the sequences of <ReferenceToOurType refuri="Some_item">Some_item</ReferenceToOurType>, and are passed
+            on to the generic sequences of <ReferenceToOurType refuri="Item">Item</ReferenceToOurType>, required as well as optional.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='optional_names_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=OptionalTypeAnnotation(
+            value=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Item',
+                parsed=...),
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Pass an optional generic sequence on to a generic sequence.</paragraph>',
+        remarks=[],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='some_names_are_unique',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='some_items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Some_item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...),
+        Argument(
+          name='special_items',
+          type_annotation=OptionalTypeAnnotation(
+            value=ListTypeAnnotation(
+              items=OurTypeAnnotation(
+                our_type='Reference to our type Special_item',
+                parsed=...),
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Pass the generic sequences of the descendants on.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The <ReferenceToArgument refuri="some_items">some_items</ReferenceToArgument> are passed on as a required and as an optional
+            sequence of the parent class, while the <ReferenceToArgument refuri="special_items">special_items</ReferenceToArgument> are passed on
+            as an optional sequence and, once narrowed, as a required sequence of the parent
+            class of the parent class.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...),
+    TranspilableVerification(
+      name='levels_are_positive',
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=ListTypeAnnotation(
+            items=OurTypeAnnotation(
+              our_type='Reference to our type Special_item',
+              parsed=...),
+            parsed=...),
+          default=None,
+          mutable=False,
+          parsed=...)],
+      returns=PrimitiveTypeAnnotation(
+        a_type='BOOL',
+        parsed=...),
+      description=DescriptionOfSignature(
+        summary='<paragraph>Check that the levels are positive.</paragraph>',
+        remarks=[
+          textwrap.dedent("""\
+            <paragraph>The <ReferenceToOurType refuri="Special_item">Special_item</ReferenceToOurType> has no descendants, so the <ReferenceToArgument refuri="items">items</ReferenceToArgument> are not
+            a generic sequence.</paragraph>""")],
+        arguments_by_name=[],
+        returns=None,
+        parsed=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      parsed=...,
+      arguments_by_name=...)],
+  verification_functions_by_name=...,
+  meta_model=MetaModel(
+    description=DescriptionOfMetaModel(
+      summary='<paragraph>Test the variance of the containers passed as arguments.</paragraph>',
+      remarks=[
+        textwrap.dedent("""\
+          <paragraph>A read-only <literal>Sequence[...]</literal> argument of a verification function is generic if its
+          items are instances of a class with descendants, so that the sequences of
+          the descendants can be passed to it without a copy. The arguments of the methods
+          and the mutable <literal>List[...]</literal> arguments remain invariant.</paragraph>""")],
+      constraints_by_identifier=[],
+      parsed=...),
+    version='dummy',
+    xml_namespace='https://dummy.com'))
\ No newline at end of file
diff --git a/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/include/dummy/verification.hpp b/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/include/dummy/verification.hpp
index d46b61dbb..57bd5c1ee 100644
--- a/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/include/dummy/verification.hpp
+++ b/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/include/dummy/verification.hpp
@@ -5,13 +5,18 @@
 // Do NOT edit or append.
 
 #include "dummy/common.hpp"
+#include "dummy/constants.hpp"
 #include "dummy/iteration.hpp"
 #include "dummy/pattern.hpp"
+#include "dummy/stringification.hpp"
 #include "dummy/types.hpp"
 
 #pragma warning(push, 0)
+#include <memory>
 #include <set>
+#include <type_traits>
 #include <unordered_set>
+#include <vector>
 #pragma warning(pop)
 
 namespace dummy {
@@ -216,9 +221,14 @@ class RecursiveVerification : public IVerification {
 // region Verification functions
 
 /// \brief Check an optional class declared with `None` and assigned in a loop.
+///
+/// \tparam ParentsT type of the items of \p parents, types::IParent or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ParentsT
+>
 bool FirstChildAIsSmall(
   const std::vector<
-    std::shared_ptr<types::IParent>
+    std::shared_ptr<ParentsT>
   >& parents
 );
 
@@ -228,10 +238,15 @@ bool TextIsAllowedUnlessLong(
 );
 
 /// \brief Check a non-optional variable declared wider than its value.
+///
+/// \tparam ParentsT type of the items of \p parents, types::IParent or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ParentsT
+>
 bool LastChildBIsNotZero(
   const std::shared_ptr<types::IParent>& parent,
   const std::vector<
-    std::shared_ptr<types::IParent>
+    std::shared_ptr<ParentsT>
   >& parents
 );
 
@@ -326,6 +341,60 @@ bool NoneIsShortAndTextIsShort(
 
 // endregion Verification functions
 
+// region Definitions of generic verification functions
+
+template<
+  typename ParentsT
+>
+bool FirstChildAIsSmall(
+  const std::vector<
+    std::shared_ptr<ParentsT>
+  >& parents
+) {
+  static_assert(
+    std::is_base_of<types::IParent, ParentsT>::value,
+    "Expected the items of parents to be instances of types::IParent"
+  );
+  common::optional<std::shared_ptr<types::IChildA> > found = common::nullopt;
+  for (const std::shared_ptr<ParentsT>& parent : parents) {
+    if (types::IsChildA(*parent)) {
+      found = std::dynamic_pointer_cast<types::IChildA>(parent);
+      break;
+    }
+  }
+  if (!(found.has_value())) {
+    return true;
+  }
+  return (*found)->a_only() < 100;
+}
+
+template<
+  typename ParentsT
+>
+bool LastChildBIsNotZero(
+  const std::shared_ptr<types::IParent>& parent,
+  const std::vector<
+    std::shared_ptr<ParentsT>
+  >& parents
+) {
+  static_assert(
+    std::is_base_of<types::IParent, ParentsT>::value,
+    "Expected the items of parents to be instances of types::IParent"
+  );
+  std::shared_ptr<types::IParent> last = parent;
+  for (const std::shared_ptr<ParentsT>& other : parents) {
+    last = other;
+  }
+  if (types::IsChildB(*last)) {
+    return (
+      std::dynamic_pointer_cast<types::IChildB>(last)->b_only() != 0
+    );
+  }
+  return true;
+}
+
+// endregion Definitions of generic verification functions
+
 // region Verification of constrained primitives
 
 /**
diff --git a/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/src/verification.cpp b/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/src/verification.cpp
index 2eb24080f..067a15066 100644
--- a/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/src/verification.cpp
+++ b/dev/test_data/main/cpp/expected/annotated_assignments/expected_output/src/verification.cpp
@@ -39,24 +39,6 @@ Error::Error(
 
 // region Verification functions
 
-bool FirstChildAIsSmall(
-  const std::vector<
-    std::shared_ptr<types::IParent>
-  >& parents
-) {
-  common::optional<std::shared_ptr<types::IChildA> > found = common::nullopt;
-  for (const std::shared_ptr<types::IParent>& parent : parents) {
-    if (types::IsChildA(*parent)) {
-      found = std::dynamic_pointer_cast<types::IChildA>(parent);
-      break;
-    }
-  }
-  if (!(found.has_value())) {
-    return true;
-  }
-  return (*found)->a_only() < 100;
-}
-
 bool TextIsAllowedUnlessLong(
   const common::optional<std::wstring>& text
 ) {
@@ -94,24 +76,6 @@ bool TextIsAllowedUnlessLong(
   );
 }
 
-bool LastChildBIsNotZero(
-  const std::shared_ptr<types::IParent>& parent,
-  const std::vector<
-    std::shared_ptr<types::IParent>
-  >& parents
-) {
-  std::shared_ptr<types::IParent> last = parent;
-  for (const std::shared_ptr<types::IParent>& other : parents) {
-    last = other;
-  }
-  if (types::IsChildB(*last)) {
-    return (
-      std::dynamic_pointer_cast<types::IChildB>(last)->b_only() != 0
-    );
-  }
-  return true;
-}
-
 bool ChildADeclarationsAgree(
   const std::shared_ptr<types::IParent>& parent
 ) {
diff --git a/dev/test_data/main/cpp/expected/if_statements/expected_output/include/dummy/verification.hpp b/dev/test_data/main/cpp/expected/if_statements/expected_output/include/dummy/verification.hpp
index 5c1a8dd3f..bedfafb04 100644
--- a/dev/test_data/main/cpp/expected/if_statements/expected_output/include/dummy/verification.hpp
+++ b/dev/test_data/main/cpp/expected/if_statements/expected_output/include/dummy/verification.hpp
@@ -5,12 +5,17 @@
 // Do NOT edit or append.
 
 #include "dummy/common.hpp"
+#include "dummy/constants.hpp"
 #include "dummy/iteration.hpp"
 #include "dummy/pattern.hpp"
+#include "dummy/stringification.hpp"
 #include "dummy/types.hpp"
 
 #pragma warning(push, 0)
+#include <memory>
 #include <set>
+#include <type_traits>
+#include <vector>
 #pragma warning(pop)
 
 namespace dummy {
@@ -297,16 +302,26 @@ bool NarrowingAfterTheOnlyCompletingBranch(
 );
 
 /// \brief Check the narrowing after the `continue` and the early return in a loop.
+///
+/// \tparam ParentsT type of the items of \p parents, types::IParent or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ParentsT
+>
 bool ChildAsHaveTexts(
   const std::vector<
-    std::shared_ptr<types::IParent>
+    std::shared_ptr<ParentsT>
   >& parents
 );
 
 /// \brief Check the narrowing after the `continue` in a loop with a `break`.
+///
+/// \tparam ParentsT type of the items of \p parents, types::IParent or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ParentsT
+>
 bool TextsBeforeContainerAreShort(
   const std::vector<
-    std::shared_ptr<types::IParent>
+    std::shared_ptr<ParentsT>
   >& parents
 );
 
@@ -316,10 +331,15 @@ bool TextOrDefaultIsShort(
 );
 
 /// \brief Check the narrowing of a variable to a class by the assigned value.
+///
+/// \tparam ParentsT type of the items of \p parents, types::IParent or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ParentsT
+>
 bool LastChildAIsSmall(
   const std::shared_ptr<types::IParent>& parent,
   const std::vector<
-    std::shared_ptr<types::IParent>
+    std::shared_ptr<ParentsT>
   >& parents
 );
 
@@ -330,6 +350,88 @@ bool HasMarkerInTree(
 
 // endregion Verification functions
 
+// region Definitions of generic verification functions
+
+template<
+  typename ParentsT
+>
+bool ChildAsHaveTexts(
+  const std::vector<
+    std::shared_ptr<ParentsT>
+  >& parents
+) {
+  static_assert(
+    std::is_base_of<types::IParent, ParentsT>::value,
+    "Expected the items of parents to be instances of types::IParent"
+  );
+  for (const std::shared_ptr<ParentsT>& parent : parents) {
+    if (!types::IsChildA(*parent)) {
+      continue;
+    }
+    if (!(std::dynamic_pointer_cast<types::IChildA>(parent)->optional_text().has_value())) {
+      return false;
+    }
+    if (common::LenStr((*(std::dynamic_pointer_cast<types::IChildA>(parent)->optional_text()))) < 1) {
+      return false;
+    }
+  }
+  return true;
+}
+
+template<
+  typename ParentsT
+>
+bool TextsBeforeContainerAreShort(
+  const std::vector<
+    std::shared_ptr<ParentsT>
+  >& parents
+) {
+  static_assert(
+    std::is_base_of<types::IParent, ParentsT>::value,
+    "Expected the items of parents to be instances of types::IParent"
+  );
+  int64_t total = 0;
+  for (const std::shared_ptr<ParentsT>& parent : parents) {
+    if (types::IsContainer(*parent)) {
+      break;
+    }
+    if (!(parent->optional_text().has_value())) {
+      continue;
+    }
+    total = (
+      total + static_cast<int64_t>(common::LenStr((*(parent->optional_text()))))
+    );
+  }
+  return total < 20;
+}
+
+template<
+  typename ParentsT
+>
+bool LastChildAIsSmall(
+  const std::shared_ptr<types::IParent>& parent,
+  const std::vector<
+    std::shared_ptr<ParentsT>
+  >& parents
+) {
+  static_assert(
+    std::is_base_of<types::IParent, ParentsT>::value,
+    "Expected the items of parents to be instances of types::IParent"
+  );
+  auto last = parent;
+  for (const std::shared_ptr<ParentsT>& other : parents) {
+    if (types::IsChildA(*other)) {
+      last = std::dynamic_pointer_cast<types::IChildA>(other);
+      if (std::dynamic_pointer_cast<types::IChildA>(last)->a_only() >= 1000) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+// endregion Definitions of generic verification functions
+
 }  // namespace verification
 /**@}*/
 
diff --git a/dev/test_data/main/cpp/expected/if_statements/expected_output/src/verification.cpp b/dev/test_data/main/cpp/expected/if_statements/expected_output/src/verification.cpp
index 2a73dca0c..38f3271d1 100644
--- a/dev/test_data/main/cpp/expected/if_statements/expected_output/src/verification.cpp
+++ b/dev/test_data/main/cpp/expected/if_statements/expected_output/src/verification.cpp
@@ -251,45 +251,6 @@ bool NarrowingAfterTheOnlyCompletingBranch(
   );
 }
 
-bool ChildAsHaveTexts(
-  const std::vector<
-    std::shared_ptr<types::IParent>
-  >& parents
-) {
-  for (const std::shared_ptr<types::IParent>& parent : parents) {
-    if (!types::IsChildA(*parent)) {
-      continue;
-    }
-    if (!(std::dynamic_pointer_cast<types::IChildA>(parent)->optional_text().has_value())) {
-      return false;
-    }
-    if (common::LenStr((*(std::dynamic_pointer_cast<types::IChildA>(parent)->optional_text()))) < 1) {
-      return false;
-    }
-  }
-  return true;
-}
-
-bool TextsBeforeContainerAreShort(
-  const std::vector<
-    std::shared_ptr<types::IParent>
-  >& parents
-) {
-  int64_t total = 0;
-  for (const std::shared_ptr<types::IParent>& parent : parents) {
-    if (types::IsContainer(*parent)) {
-      break;
-    }
-    if (!(parent->optional_text().has_value())) {
-      continue;
-    }
-    total = (
-      total + static_cast<int64_t>(common::LenStr((*(parent->optional_text()))))
-    );
-  }
-  return total < 20;
-}
-
 bool TextOrDefaultIsShort(
   const std::shared_ptr<types::IParent>& parent
 ) {
@@ -300,24 +261,6 @@ bool TextOrDefaultIsShort(
   return common::LenStr((*text)) < 10;
 }
 
-bool LastChildAIsSmall(
-  const std::shared_ptr<types::IParent>& parent,
-  const std::vector<
-    std::shared_ptr<types::IParent>
-  >& parents
-) {
-  auto last = parent;
-  for (const std::shared_ptr<types::IParent>& other : parents) {
-    if (types::IsChildA(*other)) {
-      last = std::dynamic_pointer_cast<types::IChildA>(other);
-      if (std::dynamic_pointer_cast<types::IChildA>(last)->a_only() >= 1000) {
-        return false;
-      }
-    }
-  }
-  return true;
-}
-
 bool HasMarkerInTree(
   const std::shared_ptr<types::IParent>& parent
 ) {
diff --git a/dev/test_data/main/cpp/expected/list_of_classes/expected_output/include/dummy/verification.hpp b/dev/test_data/main/cpp/expected/list_of_classes/expected_output/include/dummy/verification.hpp
index 4b436c3b7..3152a059b 100644
--- a/dev/test_data/main/cpp/expected/list_of_classes/expected_output/include/dummy/verification.hpp
+++ b/dev/test_data/main/cpp/expected/list_of_classes/expected_output/include/dummy/verification.hpp
@@ -5,12 +5,17 @@
 // Do NOT edit or append.
 
 #include "dummy/common.hpp"
+#include "dummy/constants.hpp"
 #include "dummy/iteration.hpp"
 #include "dummy/pattern.hpp"
+#include "dummy/stringification.hpp"
 #include "dummy/types.hpp"
 
 #pragma warning(push, 0)
+#include <memory>
 #include <set>
+#include <type_traits>
+#include <vector>
 #pragma warning(pop)
 
 namespace dummy {
@@ -235,11 +240,16 @@ std::vector<
 ///
 /// The appended items are narrowed down to types::ISomeItem, while the list
 /// holds types::IAbstractItem's.
+///
+/// \tparam ItemsT type of the items of \p items, types::IAbstractItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
 std::vector<
   std::shared_ptr<types::IAbstractItem>
 > SomeItemsOf(
   const std::vector<
-    std::shared_ptr<types::IAbstractItem>
+    std::shared_ptr<ItemsT>
   >& items
 );
 
@@ -266,6 +276,35 @@ bool IsInLocalCopyOfSimples(
 
 // endregion Verification functions
 
+// region Definitions of generic verification functions
+
+template<
+  typename ItemsT
+>
+std::vector<
+  std::shared_ptr<types::IAbstractItem>
+> SomeItemsOf(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IAbstractItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IAbstractItem"
+  );
+  std::vector<std::shared_ptr<types::IAbstractItem> > result = (
+    std::vector<std::shared_ptr<types::IAbstractItem> >()
+  );
+  for (const std::shared_ptr<ItemsT>& item : items) {
+    if (types::IsSomeItem(*item)) {
+      result.push_back(std::dynamic_pointer_cast<types::ISomeItem>(item));
+    }
+  }
+  return result;
+}
+
+// endregion Definitions of generic verification functions
+
 }  // namespace verification
 /**@}*/
 
diff --git a/dev/test_data/main/cpp/expected/list_of_classes/expected_output/src/verification.cpp b/dev/test_data/main/cpp/expected/list_of_classes/expected_output/src/verification.cpp
index 226711371..ac426bb53 100644
--- a/dev/test_data/main/cpp/expected/list_of_classes/expected_output/src/verification.cpp
+++ b/dev/test_data/main/cpp/expected/list_of_classes/expected_output/src/verification.cpp
@@ -68,24 +68,6 @@ std::vector<
   return result;
 }
 
-std::vector<
-  std::shared_ptr<types::IAbstractItem>
-> SomeItemsOf(
-  const std::vector<
-    std::shared_ptr<types::IAbstractItem>
-  >& items
-) {
-  std::vector<std::shared_ptr<types::IAbstractItem> > result = (
-    std::vector<std::shared_ptr<types::IAbstractItem> >()
-  );
-  for (const std::shared_ptr<types::IAbstractItem>& item : items) {
-    if (types::IsSomeItem(*item)) {
-      result.push_back(std::dynamic_pointer_cast<types::ISomeItem>(item));
-    }
-  }
-  return result;
-}
-
 bool IsInSimples(
   const std::shared_ptr<types::ISimple>& simple,
   const std::vector<
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/common.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/common.hpp
new file mode 100644
index 000000000..867ddb01b
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/common.hpp
@@ -0,0 +1,10196 @@
+#ifndef DUMMY_GUARD_
+#define DUMMY_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#pragma warning(push, 0)
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <utility>
+#pragma warning(pop)
+
+// NOTE (mristin):
+// See: https://stackoverflow.com/questions/2324658/how-to-determine-the-version-of-the-c-standard-used-by-the-compiler
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
+// NOTE (mristin):
+// Standard library provides std::optional in C++17 and above.
+#pragma warning(push, 0)
+#include <optional>
+#pragma warning(pop)
+#else
+// NOTE (mristin):
+// We rely on https://github.com/TartanLlama/optional for optional structure.
+#pragma warning(push, 0)
+#include <tl/optional.hpp>
+#pragma warning(pop)
+#endif
+
+// NOTE (mristin):
+// We check for the version above C++20 as there is no C++23 literal yet, and
+// std::expected is available only in C++23.
+// See: https://stackoverflow.com/questions/2324658/how-to-determine-the-version-of-the-c-standard-used-by-the-compiler
+// and: http://eel.is/c++draft/cpp.predefined#1.1
+#if ((defined(_MSVC_LANG) && _MSVC_LANG > 202002L) || __cplusplus > 202002L)
+// Standard library provides std::expected in C++23 and above.
+#pragma warning(push, 0)
+#include <expected>
+#pragma warning(pop)
+#else
+// NOTE (mristin):
+// We rely on https://github.com/TartanLlama/expected for expected structure.
+#pragma warning(push, 0)
+#include <tl/expected.hpp>
+#pragma warning(pop)
+#endif
+
+#pragma warning(push, 0)
+#include <cstdint>
+#include <cwchar>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup common Common functionality used throughout the library
+ * @{
+ */
+namespace common {
+
+// Please keep in sync with the preprocessing directives above in the include block.
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
+// Standard library provides std::optional in C++17 and above.
+using std::optional;
+using std::nullopt;
+using std::make_optional;
+#else
+using tl::optional;
+using tl::nullopt;
+using tl::make_optional;
+#endif
+
+// Please keep in sync with the preprocessing directives above in the include block.
+#if ((defined(_MSVC_LANG) && _MSVC_LANG > 202002L) || __cplusplus > 202002L)
+using std::expected;
+using std::unexpected;
+using std::make_unexpected;
+#else
+using tl::expected;
+using tl::unexpected;
+using tl::make_unexpected;
+#endif
+
+// Please keep in sync with the preprocessing directives above in the include block.
+// Standard library provides std::make_unique in C++14 and above.
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201402L) || __cplusplus >= 201402L)
+using std::make_unique;
+#else
+// Inspired by:
+// https://stackoverflow.com/questions/12547983/is-there-a-way-to-write-make-unique-in-vs2012
+template<typename T>
+std::unique_ptr<T> make_unique() {
+  return std::unique_ptr<T>(
+    new T()
+  );
+}
+
+template<
+  typename T,
+  typename A1
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10,
+  typename A11
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10,
+  A11&& a11
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10),
+      std::forward<A11>(a11)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10,
+  typename A11,
+  typename A12
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10,
+  A11&& a11,
+  A12&& a12
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10),
+      std::forward<A11>(a11),
+      std::forward<A12>(a12)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10,
+  typename A11,
+  typename A12,
+  typename A13
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10,
+  A11&& a11,
+  A12&& a12,
+  A13&& a13
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10),
+      std::forward<A11>(a11),
+      std::forward<A12>(a12),
+      std::forward<A13>(a13)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10,
+  typename A11,
+  typename A12,
+  typename A13,
+  typename A14
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10,
+  A11&& a11,
+  A12&& a12,
+  A13&& a13,
+  A14&& a14
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10),
+      std::forward<A11>(a11),
+      std::forward<A12>(a12),
+      std::forward<A13>(a13),
+      std::forward<A14>(a14)
+    )
+  );
+}
+
+template<
+  typename T,
+  typename A1,
+  typename A2,
+  typename A3,
+  typename A4,
+  typename A5,
+  typename A6,
+  typename A7,
+  typename A8,
+  typename A9,
+  typename A10,
+  typename A11,
+  typename A12,
+  typename A13,
+  typename A14,
+  typename A15
+>
+std::unique_ptr<T> make_unique(
+  A1&& a1,
+  A2&& a2,
+  A3&& a3,
+  A4&& a4,
+  A5&& a5,
+  A6&& a6,
+  A7&& a7,
+  A8&& a8,
+  A9&& a9,
+  A10&& a10,
+  A11&& a11,
+  A12&& a12,
+  A13&& a13,
+  A14&& a14,
+  A15&& a15
+) {
+  return std::unique_ptr<T>(
+    new T(
+      std::forward<A1>(a1),
+      std::forward<A2>(a2),
+      std::forward<A3>(a3),
+      std::forward<A4>(a4),
+      std::forward<A5>(a5),
+      std::forward<A6>(a6),
+      std::forward<A7>(a7),
+      std::forward<A8>(a8),
+      std::forward<A9>(a9),
+      std::forward<A10>(a10),
+      std::forward<A11>(a11),
+      std::forward<A12>(a12),
+      std::forward<A13>(a13),
+      std::forward<A14>(a14),
+      std::forward<A15>(a15)
+    )
+  );
+}
+#endif
+
+/**
+ * Concatenate 2 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \return a concatenation of the 2 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1
+);
+
+/**
+ * Concatenate 3 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \return a concatenation of the 3 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2
+);
+
+/**
+ * Concatenate 4 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \return a concatenation of the 4 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3
+);
+
+/**
+ * Concatenate 5 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \return a concatenation of the 5 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4
+);
+
+/**
+ * Concatenate 6 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \return a concatenation of the 6 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5
+);
+
+/**
+ * Concatenate 7 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \return a concatenation of the 7 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6
+);
+
+/**
+ * Concatenate 8 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \return a concatenation of the 8 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7
+);
+
+/**
+ * Concatenate 9 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \return a concatenation of the 9 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8
+);
+
+/**
+ * Concatenate 10 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \return a concatenation of the 10 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9
+);
+
+/**
+ * Concatenate 11 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \return a concatenation of the 11 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10
+);
+
+/**
+ * Concatenate 12 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \return a concatenation of the 12 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11
+);
+
+/**
+ * Concatenate 13 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \return a concatenation of the 13 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12
+);
+
+/**
+ * Concatenate 14 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \return a concatenation of the 14 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13
+);
+
+/**
+ * Concatenate 15 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \return a concatenation of the 15 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14
+);
+
+/**
+ * Concatenate 16 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \return a concatenation of the 16 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15
+);
+
+/**
+ * Concatenate 17 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \return a concatenation of the 17 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16
+);
+
+/**
+ * Concatenate 18 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \return a concatenation of the 18 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17
+);
+
+/**
+ * Concatenate 19 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \return a concatenation of the 19 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18
+);
+
+/**
+ * Concatenate 20 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \return a concatenation of the 20 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19
+);
+
+/**
+ * Concatenate 21 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \return a concatenation of the 21 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20
+);
+
+/**
+ * Concatenate 22 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \return a concatenation of the 22 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21
+);
+
+/**
+ * Concatenate 23 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \return a concatenation of the 23 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22
+);
+
+/**
+ * Concatenate 24 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \return a concatenation of the 24 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23
+);
+
+/**
+ * Concatenate 25 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \return a concatenation of the 25 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24
+);
+
+/**
+ * Concatenate 26 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \return a concatenation of the 26 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25
+);
+
+/**
+ * Concatenate 27 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \return a concatenation of the 27 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26
+);
+
+/**
+ * Concatenate 28 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \return a concatenation of the 28 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27
+);
+
+/**
+ * Concatenate 29 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \return a concatenation of the 29 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28
+);
+
+/**
+ * Concatenate 30 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \return a concatenation of the 30 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29
+);
+
+/**
+ * Concatenate 31 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \return a concatenation of the 31 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30
+);
+
+/**
+ * Concatenate 32 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \return a concatenation of the 32 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31
+);
+
+/**
+ * Concatenate 33 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \return a concatenation of the 33 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32
+);
+
+/**
+ * Concatenate 34 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \return a concatenation of the 34 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33
+);
+
+/**
+ * Concatenate 35 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \return a concatenation of the 35 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34
+);
+
+/**
+ * Concatenate 36 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \return a concatenation of the 36 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35
+);
+
+/**
+ * Concatenate 37 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \return a concatenation of the 37 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36
+);
+
+/**
+ * Concatenate 38 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \return a concatenation of the 38 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37
+);
+
+/**
+ * Concatenate 39 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \return a concatenation of the 39 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38
+);
+
+/**
+ * Concatenate 40 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \return a concatenation of the 40 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39
+);
+
+/**
+ * Concatenate 41 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \return a concatenation of the 41 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40
+);
+
+/**
+ * Concatenate 42 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \return a concatenation of the 42 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41
+);
+
+/**
+ * Concatenate 43 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \return a concatenation of the 43 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42
+);
+
+/**
+ * Concatenate 44 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \return a concatenation of the 44 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43
+);
+
+/**
+ * Concatenate 45 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \return a concatenation of the 45 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44
+);
+
+/**
+ * Concatenate 46 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \return a concatenation of the 46 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45
+);
+
+/**
+ * Concatenate 47 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \return a concatenation of the 47 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46
+);
+
+/**
+ * Concatenate 48 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \return a concatenation of the 48 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47
+);
+
+/**
+ * Concatenate 49 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \return a concatenation of the 49 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48
+);
+
+/**
+ * Concatenate 50 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \return a concatenation of the 50 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49
+);
+
+/**
+ * Concatenate 51 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \return a concatenation of the 51 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50
+);
+
+/**
+ * Concatenate 52 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \return a concatenation of the 52 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51
+);
+
+/**
+ * Concatenate 53 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \return a concatenation of the 53 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52
+);
+
+/**
+ * Concatenate 54 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \return a concatenation of the 54 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53
+);
+
+/**
+ * Concatenate 55 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \return a concatenation of the 55 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54
+);
+
+/**
+ * Concatenate 56 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \return a concatenation of the 56 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55
+);
+
+/**
+ * Concatenate 57 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \return a concatenation of the 57 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56
+);
+
+/**
+ * Concatenate 58 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \return a concatenation of the 58 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57
+);
+
+/**
+ * Concatenate 59 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \return a concatenation of the 59 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58
+);
+
+/**
+ * Concatenate 60 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \return a concatenation of the 60 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59
+);
+
+/**
+ * Concatenate 61 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \return a concatenation of the 61 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60
+);
+
+/**
+ * Concatenate 62 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \return a concatenation of the 62 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61
+);
+
+/**
+ * Concatenate 63 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \param part62 63rd part of the concatenation
+ * \return a concatenation of the 63 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61,
+  const std::string& part62
+);
+
+/**
+ * Concatenate 64 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \param part62 63rd part of the concatenation
+ * \param part63 64th part of the concatenation
+ * \return a concatenation of the 64 parts
+ */
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61,
+  const std::string& part62,
+  const std::string& part63
+);
+
+/**
+ * Concatenate 2 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \return a concatenation of the 2 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1
+);
+
+/**
+ * Concatenate 3 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \return a concatenation of the 3 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2
+);
+
+/**
+ * Concatenate 4 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \return a concatenation of the 4 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3
+);
+
+/**
+ * Concatenate 5 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \return a concatenation of the 5 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4
+);
+
+/**
+ * Concatenate 6 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \return a concatenation of the 6 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5
+);
+
+/**
+ * Concatenate 7 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \return a concatenation of the 7 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6
+);
+
+/**
+ * Concatenate 8 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \return a concatenation of the 8 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7
+);
+
+/**
+ * Concatenate 9 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \return a concatenation of the 9 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8
+);
+
+/**
+ * Concatenate 10 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \return a concatenation of the 10 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9
+);
+
+/**
+ * Concatenate 11 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \return a concatenation of the 11 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10
+);
+
+/**
+ * Concatenate 12 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \return a concatenation of the 12 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11
+);
+
+/**
+ * Concatenate 13 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \return a concatenation of the 13 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12
+);
+
+/**
+ * Concatenate 14 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \return a concatenation of the 14 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13
+);
+
+/**
+ * Concatenate 15 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \return a concatenation of the 15 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14
+);
+
+/**
+ * Concatenate 16 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \return a concatenation of the 16 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15
+);
+
+/**
+ * Concatenate 17 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \return a concatenation of the 17 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16
+);
+
+/**
+ * Concatenate 18 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \return a concatenation of the 18 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17
+);
+
+/**
+ * Concatenate 19 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \return a concatenation of the 19 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18
+);
+
+/**
+ * Concatenate 20 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \return a concatenation of the 20 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19
+);
+
+/**
+ * Concatenate 21 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \return a concatenation of the 21 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20
+);
+
+/**
+ * Concatenate 22 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \return a concatenation of the 22 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21
+);
+
+/**
+ * Concatenate 23 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \return a concatenation of the 23 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22
+);
+
+/**
+ * Concatenate 24 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \return a concatenation of the 24 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23
+);
+
+/**
+ * Concatenate 25 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \return a concatenation of the 25 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24
+);
+
+/**
+ * Concatenate 26 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \return a concatenation of the 26 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25
+);
+
+/**
+ * Concatenate 27 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \return a concatenation of the 27 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26
+);
+
+/**
+ * Concatenate 28 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \return a concatenation of the 28 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27
+);
+
+/**
+ * Concatenate 29 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \return a concatenation of the 29 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28
+);
+
+/**
+ * Concatenate 30 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \return a concatenation of the 30 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29
+);
+
+/**
+ * Concatenate 31 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \return a concatenation of the 31 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30
+);
+
+/**
+ * Concatenate 32 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \return a concatenation of the 32 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31
+);
+
+/**
+ * Concatenate 33 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \return a concatenation of the 33 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32
+);
+
+/**
+ * Concatenate 34 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \return a concatenation of the 34 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33
+);
+
+/**
+ * Concatenate 35 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \return a concatenation of the 35 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34
+);
+
+/**
+ * Concatenate 36 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \return a concatenation of the 36 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35
+);
+
+/**
+ * Concatenate 37 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \return a concatenation of the 37 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36
+);
+
+/**
+ * Concatenate 38 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \return a concatenation of the 38 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37
+);
+
+/**
+ * Concatenate 39 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \return a concatenation of the 39 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38
+);
+
+/**
+ * Concatenate 40 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \return a concatenation of the 40 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39
+);
+
+/**
+ * Concatenate 41 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \return a concatenation of the 41 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40
+);
+
+/**
+ * Concatenate 42 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \return a concatenation of the 42 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41
+);
+
+/**
+ * Concatenate 43 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \return a concatenation of the 43 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42
+);
+
+/**
+ * Concatenate 44 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \return a concatenation of the 44 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43
+);
+
+/**
+ * Concatenate 45 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \return a concatenation of the 45 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44
+);
+
+/**
+ * Concatenate 46 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \return a concatenation of the 46 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45
+);
+
+/**
+ * Concatenate 47 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \return a concatenation of the 47 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46
+);
+
+/**
+ * Concatenate 48 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \return a concatenation of the 48 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47
+);
+
+/**
+ * Concatenate 49 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \return a concatenation of the 49 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48
+);
+
+/**
+ * Concatenate 50 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \return a concatenation of the 50 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49
+);
+
+/**
+ * Concatenate 51 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \return a concatenation of the 51 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50
+);
+
+/**
+ * Concatenate 52 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \return a concatenation of the 52 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51
+);
+
+/**
+ * Concatenate 53 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \return a concatenation of the 53 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52
+);
+
+/**
+ * Concatenate 54 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \return a concatenation of the 54 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53
+);
+
+/**
+ * Concatenate 55 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \return a concatenation of the 55 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54
+);
+
+/**
+ * Concatenate 56 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \return a concatenation of the 56 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55
+);
+
+/**
+ * Concatenate 57 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \return a concatenation of the 57 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56
+);
+
+/**
+ * Concatenate 58 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \return a concatenation of the 58 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57
+);
+
+/**
+ * Concatenate 59 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \return a concatenation of the 59 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58
+);
+
+/**
+ * Concatenate 60 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \return a concatenation of the 60 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59
+);
+
+/**
+ * Concatenate 61 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \return a concatenation of the 61 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60
+);
+
+/**
+ * Concatenate 62 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \return a concatenation of the 62 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61
+);
+
+/**
+ * Concatenate 63 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \param part62 63rd part of the concatenation
+ * \return a concatenation of the 63 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61,
+  const std::wstring& part62
+);
+
+/**
+ * Concatenate 64 strings.
+ *
+ * \param part0 1st part of the concatenation
+ * \param part1 2nd part of the concatenation
+ * \param part2 3rd part of the concatenation
+ * \param part3 4th part of the concatenation
+ * \param part4 5th part of the concatenation
+ * \param part5 6th part of the concatenation
+ * \param part6 7th part of the concatenation
+ * \param part7 8th part of the concatenation
+ * \param part8 9th part of the concatenation
+ * \param part9 10th part of the concatenation
+ * \param part10 11st part of the concatenation
+ * \param part11 12nd part of the concatenation
+ * \param part12 13rd part of the concatenation
+ * \param part13 14th part of the concatenation
+ * \param part14 15th part of the concatenation
+ * \param part15 16th part of the concatenation
+ * \param part16 17th part of the concatenation
+ * \param part17 18th part of the concatenation
+ * \param part18 19th part of the concatenation
+ * \param part19 20th part of the concatenation
+ * \param part20 21st part of the concatenation
+ * \param part21 22nd part of the concatenation
+ * \param part22 23rd part of the concatenation
+ * \param part23 24th part of the concatenation
+ * \param part24 25th part of the concatenation
+ * \param part25 26th part of the concatenation
+ * \param part26 27th part of the concatenation
+ * \param part27 28th part of the concatenation
+ * \param part28 29th part of the concatenation
+ * \param part29 30th part of the concatenation
+ * \param part30 31st part of the concatenation
+ * \param part31 32nd part of the concatenation
+ * \param part32 33rd part of the concatenation
+ * \param part33 34th part of the concatenation
+ * \param part34 35th part of the concatenation
+ * \param part35 36th part of the concatenation
+ * \param part36 37th part of the concatenation
+ * \param part37 38th part of the concatenation
+ * \param part38 39th part of the concatenation
+ * \param part39 40th part of the concatenation
+ * \param part40 41st part of the concatenation
+ * \param part41 42nd part of the concatenation
+ * \param part42 43rd part of the concatenation
+ * \param part43 44th part of the concatenation
+ * \param part44 45th part of the concatenation
+ * \param part45 46th part of the concatenation
+ * \param part46 47th part of the concatenation
+ * \param part47 48th part of the concatenation
+ * \param part48 49th part of the concatenation
+ * \param part49 50th part of the concatenation
+ * \param part50 51st part of the concatenation
+ * \param part51 52nd part of the concatenation
+ * \param part52 53rd part of the concatenation
+ * \param part53 54th part of the concatenation
+ * \param part54 55th part of the concatenation
+ * \param part55 56th part of the concatenation
+ * \param part56 57th part of the concatenation
+ * \param part57 58th part of the concatenation
+ * \param part58 59th part of the concatenation
+ * \param part59 60th part of the concatenation
+ * \param part60 61st part of the concatenation
+ * \param part61 62nd part of the concatenation
+ * \param part62 63rd part of the concatenation
+ * \param part63 64th part of the concatenation
+ * \return a concatenation of the 64 parts
+ */
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61,
+  const std::wstring& part62,
+  const std::wstring& part63
+);
+
+/**
+ * Check if all the elements satisfy the \p condition.
+ *
+ * \param condition returning a boolean to be checked for each element
+ * \param container to be iterated through
+ * \return `true` if all the elements of \p container satisfy the \p condition
+ */
+template<typename ContainerT, typename FunctorT>
+bool All(
+  FunctorT condition,
+  const ContainerT& container
+) {
+  for (const auto& item : container ) {
+    if (!condition(item)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+/**
+ * Check if any of the elements satisfy the \p condition.
+ *
+ * \param condition returning a boolean to be checked for each element
+ * \param container to be iterated through
+ * \return `true` if any of the elements of \p container satisfy the \p condition
+ */
+template<typename ContainerT, typename FunctorT>
+bool Some(
+  FunctorT condition,
+  const ContainerT& container
+) {
+  for (const auto& item : container ) {
+    if (condition(item)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/**
+ * Check if all the numbers in the range `[start, end)` satisfy the \p condition.
+ *
+ * The `IntegerT` is either `size_t` for the lengths, or `int64_t` for
+ * the integers, and needs to be given explicitly.
+ *
+ * \param condition returning a boolean to be checked for each number
+ * \param start of the range
+ * \param end of the range
+ * \return \parblock
+ * `true` if all the numbers between \p start and \p end (excluded)
+ * satisfy the \p condition
+ * \endparblock
+ */
+template<typename IntegerT, typename FunctorT>
+bool AllRange(
+  FunctorT condition,
+  IntegerT start,
+  IntegerT end
+) {
+  for (IntegerT i = start; i < end; ++i) {
+    if (!condition(i)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+/**
+ * Check if any number in the range `[start, end)` satisfy the \p condition.
+ *
+ * The `IntegerT` is either `size_t` for the lengths, or `int64_t` for
+ * the integers, and needs to be given explicitly.
+ *
+ * \param condition returning a boolean to be checked for each number
+ * \param start of the range
+ * \param end of the range
+ * \return \parblock
+ * `true` if any number between \p start and
+ * \p end (excluded) satisfy the \p condition
+ * \endparblock
+ */
+template<typename IntegerT, typename FunctorT>
+bool SomeRange(
+  FunctorT condition,
+  IntegerT start,
+  IntegerT end
+) {
+  for (IntegerT i = start; i < end; ++i) {
+    if (condition(i)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/**
+ * Check if the \p container contains the \p value.
+ *
+ * \param container to be searched through
+ * \param value to be search for
+ * \return `true` if \p value is in the \p container
+ */
+template<typename ContainerT, typename ValueT>
+bool Contains(
+  const ContainerT& container,
+  const ValueT& value
+) {
+  const auto container_begin = std::begin(container);
+  const auto container_end = std::end(container);
+  return std::find(
+    container_begin,
+    container_end,
+    value
+  ) != container_end;
+}
+
+/**
+ * Convert platform-independent the wide string to a UTF-8 string.
+ *
+ * \param text to be converted
+ * \return UTF-8 encoded \p text
+ */
+std::string WstringToUtf8(const std::wstring& text);
+
+/**
+ * Convert platform-independent the UTF-8 encoded string to a wide string.
+ *
+ * \param utf8_text UTF-8 encoded text to be converted
+ * \param utf8_text_size size of the text to be converted. If std::string::npos,
+ * the \p utf8_text is assumed to be null-terminated and the size is determined
+ * using `strlen`.
+ * \return the wide-string representation
+ */
+std::wstring Utf8ToWstring(
+  const char* utf8_text,
+  size_t utf8_text_size = std::string::npos
+);
+
+/**
+ * Convert platform-independent the UTF-8 encoded string to a wide string.
+ *
+ * \param utf8_text UTF-8 encoded text to be converted
+ * \return wide string
+ */
+std::wstring Utf8ToWstring(const std::string& utf8_text);
+
+/**
+ * Count the items of a tuple.
+ *
+ * \return the number of items
+ */
+template<typename... T>
+size_t LenTuple(const std::tuple<T...>&) {
+  return sizeof...(T);
+}
+
+/**
+ * Count the characters (code points) of \p text.
+ *
+ * We follow the Python implementation of `len`, since Python is the language of
+ * the meta-model specifications. Hence, a character beyond the Basic
+ * Multilingual Plane counts as one, unlike in `text.size()` on the platforms
+ * where `wchar_t` is a UTF-16 code unit, such as Windows.
+ *
+ * \param text to be measured
+ * \return the number of characters
+ */
+size_t LenStr(const std::wstring& text);
+
+/**
+ * Slice \p text from \p start up to \p end, exclusive.
+ *
+ * We follow the Python implementation of slicing, since Python is the language
+ * of the meta-model specifications. Hence, the positions count the characters
+ * (code points), a negative position counts from the end, the positions out of
+ * range are clamped to the string, and the slice is empty if \p start is not
+ * before \p end.
+ *
+ * \param text to be sliced
+ * \param start of the slice, inclusive
+ * \param end of the slice, exclusive
+ * \return the slice
+ */
+std::wstring SliceStr(
+  const std::wstring& text,
+  int64_t start,
+  int64_t end
+);
+
+/**
+ * Slice \p text from \p start up to its end.
+ *
+ * See the other overload for the semantics.
+ *
+ * \param text to be sliced
+ * \param start of the slice, inclusive
+ * \return the slice
+ */
+std::wstring SliceStr(
+  const std::wstring& text,
+  int64_t start
+);
+
+/**
+ * Find the first \p sub in \p text.
+ *
+ * See the other overload for the semantics.
+ *
+ * \param text to be searched in
+ * \param sub to be searched for
+ * \return the position of \p sub in \p text, or -1 if not found
+ */
+int64_t FindStr(
+  const std::wstring& text,
+  const std::wstring& sub
+);
+
+/**
+ * Find the first \p sub in \p text from \p start on.
+ *
+ * We follow the Python implementation of `str.find`, since Python is
+ * the language of the meta-model specifications. Hence, the positions count
+ * the characters (code points), a negative \p start counts from the end, and
+ * a \p start beyond the end of \p text gives -1.
+ *
+ * \param text to be searched in
+ * \param sub to be searched for
+ * \param start of the search
+ * \return the position of \p sub in \p text, or -1 if not found
+ */
+int64_t FindStr(
+  const std::wstring& text,
+  const std::wstring& sub,
+  int64_t start
+);
+
+}  // namespace common
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/constants.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/constants.hpp
new file mode 100644
index 000000000..bce8482fe
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/constants.hpp
@@ -0,0 +1,38 @@
+#ifndef DUMMY_CONSTANTS_GUARD_
+#define DUMMY_CONSTANTS_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <cstdint>
+#include <unordered_set>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup constants Pre-defined constants of the meta-model
+ * @{
+ */
+namespace constants {
+
+/**
+ * Hash a blob of bytes based on the Java's String hash.
+ */
+struct HashBytes {
+  std::size_t operator()(const std::vector<std::uint8_t>& bytes) const;
+};
+
+}  // namespace common
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_CONSTANTS_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/enhancing.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/enhancing.hpp
new file mode 100644
index 000000000..26a3a44ff
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/enhancing.hpp
@@ -0,0 +1,1104 @@
+#ifndef DUMMY_ENHANCING_GUARD_
+#define DUMMY_ENHANCING_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/stringification.hpp"
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <sstream>
+#include <stdexcept>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup enhancing Enhance instances of the model with your custom enhancements.
+ * @{
+ */
+namespace enhancing {
+
+// region Forward declarations
+
+template <typename E>
+std::shared_ptr<
+  types::IItem
+> Wrap(
+  const std::shared_ptr<
+    types::IItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+);
+
+template <typename E>
+std::shared_ptr<
+  types::ISomeItem
+> Wrap(
+  const std::shared_ptr<
+    types::ISomeItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+);
+
+template <typename E>
+std::shared_ptr<
+  types::ISpecialItem
+> Wrap(
+  const std::shared_ptr<
+    types::ISpecialItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+);
+
+template <typename E>
+std::shared_ptr<
+  types::IContainer
+> Wrap(
+  const std::shared_ptr<
+    types::IContainer
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+);
+
+template <typename E>
+std::shared_ptr<
+  types::IWrapper
+> Wrap(
+  const std::shared_ptr<
+    types::IWrapper
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+);
+
+// endregion Forward declarations
+
+/// \cond HIDDEN
+namespace impl {
+
+template<typename E>
+class IEnhanced {
+ public:
+  virtual const std::shared_ptr<E>& enhancement() const = 0;
+
+  virtual std::shared_ptr<E>& mutable_enhancement() = 0;
+
+  virtual void set_enhancement(
+    std::shared_ptr<E> value
+  ) = 0;
+
+  virtual ~IEnhanced() = default;
+};
+
+template<class E>
+class EnhancedSomeItem
+    : virtual public types::ISomeItem,
+    virtual public IEnhanced<E> {
+ public:
+  types::ModelType model_type() const override {
+    return types::ModelType::kSomeItem;
+  }
+
+  const std::wstring& name() const override {
+    return instance_->name();
+  }
+
+  std::wstring& mutable_name() override {
+    return instance_->mutable_name();
+  }
+
+  void set_name(
+    std::wstring value
+  ) override {
+    instance_->set_name(value);
+  }
+
+  const common::optional<std::wstring>& nickname() const override {
+    return instance_->nickname();
+  }
+
+  common::optional<std::wstring>& mutable_nickname() override {
+    return instance_->mutable_nickname();
+  }
+
+  void set_nickname(
+    common::optional<std::wstring> value
+  ) override {
+    instance_->set_nickname(value);
+  }
+
+  const std::shared_ptr<E>& enhancement() const {
+    return enhancement_;
+  }
+
+  std::shared_ptr<E>& mutable_enhancement() {
+    return enhancement_;
+  }
+
+  void set_enhancement(
+    std::shared_ptr<E> value
+  ) {
+    enhancement_ = std::move(value);
+  }
+
+  EnhancedSomeItem(
+    std::shared_ptr<types::ISomeItem> instance,
+    std::shared_ptr<E> enhancement
+  ) :
+    instance_(instance),
+    enhancement_(enhancement) {
+    // Intentionally empty.
+  }
+
+  virtual ~EnhancedSomeItem() = default;
+
+ private:
+  std::shared_ptr<types::ISomeItem> instance_;
+  std::shared_ptr<E> enhancement_;
+};
+
+template<class E>
+class EnhancedSpecialItem
+    : virtual public types::ISpecialItem,
+    virtual public IEnhanced<E> {
+ public:
+  types::ModelType model_type() const override {
+    return types::ModelType::kSpecialItem;
+  }
+
+  const std::wstring& name() const override {
+    return instance_->name();
+  }
+
+  std::wstring& mutable_name() override {
+    return instance_->mutable_name();
+  }
+
+  void set_name(
+    std::wstring value
+  ) override {
+    instance_->set_name(value);
+  }
+
+  const common::optional<std::wstring>& nickname() const override {
+    return instance_->nickname();
+  }
+
+  common::optional<std::wstring>& mutable_nickname() override {
+    return instance_->mutable_nickname();
+  }
+
+  void set_nickname(
+    common::optional<std::wstring> value
+  ) override {
+    instance_->set_nickname(value);
+  }
+
+  int64_t level() const override {
+    return instance_->level();
+  }
+
+  int64_t& mutable_level() override {
+    return instance_->mutable_level();
+  }
+
+  void set_level(
+    int64_t value
+  ) override {
+    instance_->set_level(value);
+  }
+
+  const std::shared_ptr<E>& enhancement() const {
+    return enhancement_;
+  }
+
+  std::shared_ptr<E>& mutable_enhancement() {
+    return enhancement_;
+  }
+
+  void set_enhancement(
+    std::shared_ptr<E> value
+  ) {
+    enhancement_ = std::move(value);
+  }
+
+  EnhancedSpecialItem(
+    std::shared_ptr<types::ISpecialItem> instance,
+    std::shared_ptr<E> enhancement
+  ) :
+    instance_(instance),
+    enhancement_(enhancement) {
+    // Intentionally empty.
+  }
+
+  virtual ~EnhancedSpecialItem() = default;
+
+ private:
+  std::shared_ptr<types::ISpecialItem> instance_;
+  std::shared_ptr<E> enhancement_;
+};
+
+template<class E>
+class EnhancedContainer
+    : virtual public types::IContainer,
+    virtual public IEnhanced<E> {
+ public:
+  types::ModelType model_type() const override {
+    return types::ModelType::kContainer;
+  }
+
+  const std::vector<
+    std::shared_ptr<types::IItem>
+  >& items() const override {
+    return instance_->items();
+  }
+
+  std::vector<
+    std::shared_ptr<types::IItem>
+  >& mutable_items() override {
+    return instance_->mutable_items();
+  }
+
+  void set_items(
+    std::vector<
+      std::shared_ptr<types::IItem>
+    > value
+  ) override {
+    instance_->set_items(value);
+  }
+
+  const std::vector<
+    std::shared_ptr<types::ISomeItem>
+  >& some_items() const override {
+    return instance_->some_items();
+  }
+
+  std::vector<
+    std::shared_ptr<types::ISomeItem>
+  >& mutable_some_items() override {
+    return instance_->mutable_some_items();
+  }
+
+  void set_some_items(
+    std::vector<
+      std::shared_ptr<types::ISomeItem>
+    > value
+  ) override {
+    instance_->set_some_items(value);
+  }
+
+  const common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& special_items() const override {
+    return instance_->special_items();
+  }
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& mutable_special_items() override {
+    return instance_->mutable_special_items();
+  }
+
+  void set_special_items(
+    common::optional<
+      std::vector<
+        std::shared_ptr<types::ISpecialItem>
+      >
+    > value
+  ) override {
+    instance_->set_special_items(value);
+  }
+
+  int64_t CountItems(
+    const std::vector<
+      std::shared_ptr<types::IItem>
+    >& items
+  ) const override {
+    return instance_->CountItems(
+      items
+    );
+  }
+
+  const std::shared_ptr<E>& enhancement() const {
+    return enhancement_;
+  }
+
+  std::shared_ptr<E>& mutable_enhancement() {
+    return enhancement_;
+  }
+
+  void set_enhancement(
+    std::shared_ptr<E> value
+  ) {
+    enhancement_ = std::move(value);
+  }
+
+  EnhancedContainer(
+    std::shared_ptr<types::IContainer> instance,
+    std::shared_ptr<E> enhancement
+  ) :
+    instance_(instance),
+    enhancement_(enhancement) {
+    // Intentionally empty.
+  }
+
+  virtual ~EnhancedContainer() = default;
+
+ private:
+  std::shared_ptr<types::IContainer> instance_;
+  std::shared_ptr<E> enhancement_;
+};
+
+template<class E>
+class EnhancedWrapper
+    : virtual public types::IWrapper,
+    virtual public IEnhanced<E> {
+ public:
+  types::ModelType model_type() const override {
+    return types::ModelType::kWrapper;
+  }
+
+  const std::shared_ptr<types::IContainer>& container() const override {
+    return instance_->container();
+  }
+
+  std::shared_ptr<types::IContainer>& mutable_container() override {
+    return instance_->mutable_container();
+  }
+
+  void set_container(
+    std::shared_ptr<types::IContainer> value
+  ) override {
+    instance_->set_container(value);
+  }
+
+  const std::shared_ptr<E>& enhancement() const {
+    return enhancement_;
+  }
+
+  std::shared_ptr<E>& mutable_enhancement() {
+    return enhancement_;
+  }
+
+  void set_enhancement(
+    std::shared_ptr<E> value
+  ) {
+    enhancement_ = std::move(value);
+  }
+
+  EnhancedWrapper(
+    std::shared_ptr<types::IWrapper> instance,
+    std::shared_ptr<E> enhancement
+  ) :
+    instance_(instance),
+    enhancement_(enhancement) {
+    // Intentionally empty.
+  }
+
+  virtual ~EnhancedWrapper() = default;
+
+ private:
+  std::shared_ptr<types::IWrapper> instance_;
+  std::shared_ptr<E> enhancement_;
+};
+
+/**
+ * Wrap recursively the instances held by \p that.
+ *
+ * \param that container of the instances to be wrapped
+ * \param factory to produce an enhancement based on an instance
+ * \return a copy of \p that with the wrapped instances
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::vector<
+  std::shared_ptr<types::IItem>
+> Wrap_listOf_Item(
+  const std::vector<
+    std::shared_ptr<types::IItem>
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  std::vector<
+    std::shared_ptr<types::IItem>
+  > result;
+  result.reserve(that.size());
+
+  for (
+    const std::shared_ptr<types::IItem>& item :
+    that
+  ) {
+    result.emplace_back(Wrap<E>(item, factory));
+  }
+
+  return result;
+}
+
+/**
+ * Wrap recursively the instances held by \p that.
+ *
+ * \param that container of the instances to be wrapped
+ * \param factory to produce an enhancement based on an instance
+ * \return a copy of \p that with the wrapped instances
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::vector<
+  std::shared_ptr<types::ISomeItem>
+> Wrap_listOf_SomeItem(
+  const std::vector<
+    std::shared_ptr<types::ISomeItem>
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  std::vector<
+    std::shared_ptr<types::ISomeItem>
+  > result;
+  result.reserve(that.size());
+
+  for (
+    const std::shared_ptr<types::ISomeItem>& item :
+    that
+  ) {
+    result.emplace_back(Wrap<E>(item, factory));
+  }
+
+  return result;
+}
+
+/**
+ * Wrap recursively the instances held by \p that.
+ *
+ * \param that container of the instances to be wrapped
+ * \param factory to produce an enhancement based on an instance
+ * \return a copy of \p that with the wrapped instances
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::vector<
+  std::shared_ptr<types::ISpecialItem>
+> Wrap_listOf_SpecialItem(
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  > result;
+  result.reserve(that.size());
+
+  for (
+    const std::shared_ptr<types::ISpecialItem>& item :
+    that
+  ) {
+    result.emplace_back(Wrap<E>(item, factory));
+  }
+
+  return result;
+}
+
+/**
+ * Wrap \p that with an enhanced instance.
+ *
+ * \param that instance to be wrapped and enhanced
+ * \param factory to produce an enhancement based on an instance
+ * \return Enhanced instance, or `that` if no enhancement produced
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::shared_ptr<types::ISomeItem> WrapSomeItem(
+  const std::shared_ptr<types::ISomeItem>& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  // We assume that we already checked whether `that` has been enhanced
+  // in the caller.
+
+  // No properties to be recursively enhanced.
+
+  std::shared_ptr<E> enh(
+    factory(that)
+  );
+  return (enh == nullptr)
+    ? that
+    : std::shared_ptr<types::ISomeItem>(
+      new EnhancedSomeItem<E>(
+        that,
+        enh
+      )
+    );
+}
+
+/**
+ * Wrap \p that with an enhanced instance.
+ *
+ * \param that instance to be wrapped and enhanced
+ * \param factory to produce an enhancement based on an instance
+ * \return Enhanced instance, or `that` if no enhancement produced
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::shared_ptr<types::ISpecialItem> WrapSpecialItem(
+  const std::shared_ptr<types::ISpecialItem>& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  // We assume that we already checked whether `that` has been enhanced
+  // in the caller.
+
+  // No properties to be recursively enhanced.
+
+  std::shared_ptr<E> enh(
+    factory(that)
+  );
+  return (enh == nullptr)
+    ? that
+    : std::shared_ptr<types::ISpecialItem>(
+      new EnhancedSpecialItem<E>(
+        that,
+        enh
+      )
+    );
+}
+
+/**
+ * Wrap \p that with an enhanced instance.
+ *
+ * \param that instance to be wrapped and enhanced
+ * \param factory to produce an enhancement based on an instance
+ * \return Enhanced instance, or `that` if no enhancement produced
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::shared_ptr<types::IContainer> WrapContainer(
+  const std::shared_ptr<types::IContainer>& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  // We assume that we already checked whether `that` has been enhanced
+  // in the caller.
+
+  that->set_items(
+    Wrap_listOf_Item<E>(that->items(), factory)
+  );
+
+  that->set_some_items(
+    Wrap_listOf_SomeItem<E>(that->some_items(), factory)
+  );
+
+  if (that->special_items().has_value()) {
+    that->set_special_items(
+      common::make_optional(
+        Wrap_listOf_SpecialItem<E>(
+          that->special_items().value(),
+          factory
+        )
+      )
+    );
+  }
+
+  std::shared_ptr<E> enh(
+    factory(that)
+  );
+  return (enh == nullptr)
+    ? that
+    : std::shared_ptr<types::IContainer>(
+      new EnhancedContainer<E>(
+        that,
+        enh
+      )
+    );
+}
+
+/**
+ * Wrap \p that with an enhanced instance.
+ *
+ * \param that instance to be wrapped and enhanced
+ * \param factory to produce an enhancement based on an instance
+ * \return Enhanced instance, or `that` if no enhancement produced
+ *
+ * \tparam E type of the enhancement
+ */
+template<typename E>
+std::shared_ptr<types::IWrapper> WrapWrapper(
+  const std::shared_ptr<types::IWrapper>& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  // We assume that we already checked whether `that` has been enhanced
+  // in the caller.
+
+  that->set_container(
+    Wrap<E>(that->container(), factory)
+  );
+
+  std::shared_ptr<E> enh(
+    factory(that)
+  );
+  return (enh == nullptr)
+    ? that
+    : std::shared_ptr<types::IWrapper>(
+      new EnhancedWrapper<E>(
+        that,
+        enh
+      )
+    );
+}
+
+/**
+ * Assert that the \p that instance has not been already enhanced.
+ *
+ * \param that instance to be checked
+ * \tparam E type of the enhancement
+ * \tparam T interface type of \p that instance
+ * \throw std::logic_error if \p that already enhanced
+ */
+template<
+  typename E,
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<types::IClass, T>::value
+  >::type* = nullptr
+>
+void AssertNotEnhanced(
+  const std::shared_ptr<T>& that
+) {
+  std::shared_ptr<impl::IEnhanced<E> > enhanced(
+    std::dynamic_pointer_cast<
+      impl::IEnhanced<E>
+    >(that)
+  );
+  if (enhanced != nullptr) {
+    throw std::logic_error(
+      common::Concat(
+        "An instance of ",
+        stringification::to_string(that->model_type()),
+        " has been already wrapped."
+      )
+    );
+  }
+}
+
+}  // namespace impl
+/// \endcond
+
+/**
+ * Wrap \p that instance recursively with the enhancement produced by the \p factory.
+ *
+ * The factory decides itself whether it will produce an enhancement for
+ * \p that instance, or not. Even if no enhancement has been produced for \p that
+ * instance, we will still continue to enhance the instances referenced
+ * by \p that instance recursively.
+ *
+ * \param that instance to wrap
+ * \param factory to selectively produce an enhancement
+ * \return enhanced \p that instance
+ * \throw std::logic_error if \p that instance has been already wrapped.
+ * \tparam E type of the enhancement
+ */
+///@{
+
+template <typename E>
+std::shared_ptr<
+  types::IClass
+> Wrap(
+  const std::shared_ptr<
+    types::IClass
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::IClass
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kSomeItem:
+      return impl::WrapSomeItem<E>(
+        std::dynamic_pointer_cast<
+          types::ISomeItem
+        >(that),
+        factory
+      );
+      break;
+    case types::ModelType::kSpecialItem:
+      return impl::WrapSpecialItem<E>(
+        std::dynamic_pointer_cast<
+          types::ISpecialItem
+        >(that),
+        factory
+      );
+      break;
+    case types::ModelType::kContainer:
+      return impl::WrapContainer<E>(
+        std::dynamic_pointer_cast<
+          types::IContainer
+        >(that),
+        factory
+      );
+      break;
+    case types::ModelType::kWrapper:
+      return impl::WrapWrapper<E>(
+        std::dynamic_pointer_cast<
+          types::IWrapper
+        >(that),
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+template <typename E>
+std::shared_ptr<
+  types::IItem
+> Wrap(
+  const std::shared_ptr<
+    types::IItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::IItem
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kSomeItem:
+      return impl::WrapSomeItem<E>(
+        std::dynamic_pointer_cast<
+          types::ISomeItem
+        >(that),
+        factory
+      );
+      break;
+    case types::ModelType::kSpecialItem:
+      return impl::WrapSpecialItem<E>(
+        std::dynamic_pointer_cast<
+          types::ISpecialItem
+        >(that),
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+template <typename E>
+std::shared_ptr<
+  types::ISomeItem
+> Wrap(
+  const std::shared_ptr<
+    types::ISomeItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::ISomeItem
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kSomeItem:
+      return impl::WrapSomeItem<E>(
+        that,
+        factory
+      );
+      break;
+    case types::ModelType::kSpecialItem:
+      return impl::WrapSpecialItem<E>(
+        std::dynamic_pointer_cast<
+          types::ISpecialItem
+        >(that),
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+template <typename E>
+std::shared_ptr<
+  types::ISpecialItem
+> Wrap(
+  const std::shared_ptr<
+    types::ISpecialItem
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::ISpecialItem
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kSpecialItem:
+      return impl::WrapSpecialItem<E>(
+        that,
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+template <typename E>
+std::shared_ptr<
+  types::IContainer
+> Wrap(
+  const std::shared_ptr<
+    types::IContainer
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::IContainer
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kContainer:
+      return impl::WrapContainer<E>(
+        that,
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+template <typename E>
+std::shared_ptr<
+  types::IWrapper
+> Wrap(
+  const std::shared_ptr<
+    types::IWrapper
+  >& that,
+  const std::function<
+    std::shared_ptr<E>(
+      const std::shared_ptr<types::IClass>&
+    )
+  >& factory
+) {
+  impl::AssertNotEnhanced<
+    E,
+    types::IWrapper
+  >(that);
+
+  switch (that->model_type()) {
+    case types::ModelType::kWrapper:
+      return impl::WrapWrapper<E>(
+        that,
+        factory
+      );
+      break;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              that->model_type()
+            )
+          )
+        )
+      );
+      break;
+  }
+}
+
+///@}}
+
+/**
+ * Try to unwrap the enhancement from \p that instance.
+ *
+ * \param that instance possibly wrapped with an enhancement
+ * \return the enhancement, or `nullptr` if \p that instance has not been wrapped
+ * \tparam E type of the enhancement
+ */
+template <typename E>
+std::shared_ptr<E> Unwrap(
+  const std::shared_ptr<types::IClass>& that
+) {
+  const std::shared_ptr<impl::IEnhanced<E> >& maybe_enhanced(
+    std::dynamic_pointer_cast<impl::IEnhanced<E> >(that)
+  );
+
+  if (!maybe_enhanced) {
+    return nullptr;
+  }
+
+  return maybe_enhanced->enhancement();
+}
+
+/**
+ * Unwrap the enhancement from \p that instance.
+ *
+ * \remark \p that instance must have been wrapped before.
+ *
+ * \param that instance expected to be wrapped with an enhancement
+ * \return the enhancement
+ * \throw std::invalid_argument if \p that instance has not been wrapped
+ * \tparam E type of the enhancement
+ */
+template <typename E>
+std::shared_ptr<E> MustUnwrap(
+  const std::shared_ptr<types::IClass>& that
+) {
+  std::shared_ptr<E> enhancement(
+    Unwrap<E>(that)
+  );
+  if (!enhancement) {
+    throw std::invalid_argument(
+      common::Concat(
+        "Expected an instance of ",
+        stringification::to_string(that->model_type()),
+        " to have been already wrapped with an enhancement, "
+        "but it has been not."
+      )
+    );
+  }
+  return enhancement;
+}
+
+}  // namespace enhancing
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_ENHANCING_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/iteration.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/iteration.hpp
new file mode 100644
index 000000000..181d9c1c1
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/iteration.hpp
@@ -0,0 +1,372 @@
+#ifndef DUMMY_ITERATION_GUARD_
+#define DUMMY_ITERATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <deque>
+#include <iterator>
+#include <memory>
+#include <string>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup iteration Define functions and structures to iterate over instances.
+ * @{
+*/
+namespace iteration {
+
+// region Pathing
+
+/**
+ * Define the properties over all the classes to compactly represent the paths.
+ */
+enum class Property : std::uint32_t {
+  kContainer = 0,
+  kItems = 1,
+  kLevel = 2,
+  kName = 3,
+  kNickname = 4,
+  kSomeItems = 5,
+  kSpecialItems = 6
+};
+
+std::wstring PropertyToWstring(
+  Property property
+);
+
+/**
+ * Represent a segment of a path to some value.
+ */
+class ISegment {
+ public:
+  virtual std::wstring ToWstring() const = 0;
+  virtual std::unique_ptr<ISegment> Clone() const = 0;
+  virtual ~ISegment() = default;
+};  // class ISegment
+
+/**
+ * Represent a property access on a path.
+ */
+struct PropertySegment : public ISegment {
+  /**
+   * Enumeration of the property
+   */
+  Property property;
+
+  PropertySegment(
+    Property a_property
+  );
+
+  std::wstring ToWstring() const override;
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~PropertySegment() override = default;
+};  // struct PropertySegment
+
+/**
+ * Represent an index access on a path.
+ */
+struct IndexSegment : public ISegment {
+  /**
+   * Index of the item
+   */
+  size_t index;
+
+  explicit IndexSegment(
+    size_t an_index
+  );
+
+  std::wstring ToWstring() const override;
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~IndexSegment() override = default;
+};  // struct IndexSegment
+
+/**
+ * \brief Represent an access to a key of a JSON-able object on a path.
+ *
+ * Unlike \ref PropertySegment, which points to one of the properties of
+ * the meta-model, this segment points to a key of a JSON-able object, which
+ * can be an arbitrary string known only at runtime.
+ */
+struct KeySegment : public ISegment {
+  /**
+   * Key of the JSON-able object
+   */
+  std::wstring key;
+
+  explicit KeySegment(
+    std::wstring a_key
+  );
+
+  std::wstring ToWstring() const override;
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~KeySegment() override = default;
+};  // struct KeySegment
+
+/**
+ * \brief Represent a path to some value.
+ *
+ * This is a path akin to C++ expressions. It is not to be confused with different
+ * paths used in the specification. This path class is meant to help with reporting.
+ * For example, we can use this path to let the user know when there is
+ * a verification error in a model which can concern instances, but also properties
+ * and items in the lists.
+ */
+struct Path {
+  // NOTE (mristin):
+  // We did not implement the reflection at the moment since we did not have a use
+  // case for it. If you need reflection, please contact the developers. It should
+  // be a small step going from paths to dereferencing to getters and setters.
+
+  std::deque<std::unique_ptr<ISegment> > segments;
+
+  Path();
+  Path(const Path& other);
+  Path(Path&& other);
+  Path& operator=(const Path& other);
+  Path& operator=(Path&& other);
+
+  std::wstring ToWstring() const;
+};  // struct Path
+
+// endregion Pathing
+
+// region Iterators and descent
+
+/// \cond HIDDEN
+namespace impl {
+class IIterator {
+ public:
+  virtual void Start() = 0;
+  virtual void Next() = 0;
+  virtual bool Done() const = 0;
+  virtual const std::shared_ptr<types::IClass>& Get() const = 0;
+
+  /**
+   * \brief Append the segments leading to the current instance to the \p path.
+   *
+   * Only called on request, so the iteration itself builds no paths.
+   */
+  virtual void AppendToPath(Path& path) const = 0;
+
+  virtual std::unique_ptr<IIterator> Clone() const = 0;
+
+  virtual ~IIterator() = default;
+};  // class IIterator
+}  // namespace impl
+/// \endcond
+
+/**
+ * \brief Iterate over a model instance.
+ *
+ * Unlike STL, this is <em>not</em> a light-weight iterator. We implement
+ * a "yielding" iterator by composing iterators over the properties so that we
+ * always keep the model stack as well as the properties iterated thus far.
+ *
+ * This means that copy-construction and equality comparisons are much more heavy-weight
+ * than you'd usually expect from an STL iterator. For example, if you want to sort
+ * model instances, you are most probably faster if you populate a vector, and then
+ * sort the vector.
+ *
+ * Also, given that this iterator is not light-weight, you should in almost all cases
+ * avoid the postfix increment (it++) and prefer the prefix one (++it) as the postfix
+ * increment would create an iterator copy every time.
+ *
+ * The value of the iterator is intentionally constant reference to a shared pointer.
+ * This merely means that you can not change the <em>pointer</em> while you are
+ * iterating. The pointed instances, however, is freely mutable. This way you can make
+ * further shared pointers, or include the pointed instances in other collections
+ * different from the original container. On the other hand, the normal case, where
+ * the pointer is only de-referenced, remains efficient as no copy of
+ * the shared pointer is created.
+ *
+ * We follow the C++ standard, and assume that comparison between the two iterators
+ * over two different instances results in undefined behavior. See
+ * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2948.html and
+ * https://stackoverflow.com/questions/4657513/comparing-iterators-from-different-containers.
+ *
+ * Since we use const references to shared pointers here you can also share ownership
+ * over instances in your own external containers. Making a copy of a shared pointer
+ * will automatically increase reference count, even though there is a constant
+ * reference. Since we do not make copies of the shared pointers, it is very important
+ * that the given shared pointers outlive the iteration, lest cause undefined behavior.
+ *
+ * Changing the references <em>during</em> the iteration invalidates the iterators and
+ * results in undefined behavior. This is similar to many of the containers in the STL,
+ * see: https://stackoverflow.com/questions/6438086/iterator-invalidation-rules-for-c-containers
+ *
+ * See these StackOverflow questions for performance related to shared pointers and
+ * constant references to shared pointers (copying <em>versus</em> referencing):
+ * * https://stackoverflow.com/questions/12002480/passing-stdshared-ptr-to-constructors/12002668#12002668
+ * * https://stackoverflow.com/questions/3310737/should-we-pass-a-shared-ptr-by-reference-or-by-value
+ * * https://stackoverflow.com/questions/37610494/passing-const-shared-ptrt-versus-just-shared-ptrt-as-parameter
+ *
+ * The following StackOverflow question and answers go into more detail how const-ness
+ * and shared pointers fit together:
+ * https://stackoverflow.com/questions/36271663/why-does-copying-a-const-shared-ptr-not-violate-const-ness
+ */
+class Iterator {
+  using iterator_category = std::forward_iterator_tag;
+  /// The difference is meaningless, but has to be defined.
+  using difference_type = std::ptrdiff_t;
+  using value_type = std::shared_ptr<types::IClass>;
+  using pointer = const std::shared_ptr<types::IClass>*;
+  using reference = const std::shared_ptr<types::IClass>&;
+
+ public:
+  Iterator(const Iterator& other);
+  Iterator(Iterator&& other);
+
+  Iterator& operator=(const Iterator& other);
+  Iterator& operator=(Iterator&& other);
+
+  reference operator*() const;
+  pointer operator->();
+
+  // Prefix increment
+  Iterator& operator++();
+
+  // Postfix increment
+  Iterator operator++(int);
+
+  friend bool operator==(const Iterator& a, const Iterator& b);
+  friend bool operator!=(const Iterator& a, const Iterator& b);
+
+  friend class Descent;
+  friend class DescentOnce;
+  friend Path MaterializePath(const Iterator& iterator);
+  friend void PrependToPath(const Iterator& iterator, Path* path);
+
+ private:
+  explicit Iterator(
+    std::unique_ptr<impl::IIterator> implementation
+  ) :
+    implementation_(std::move(implementation)),
+    index_(implementation_->Done() ? -1 : 0) {
+    // Intentionally empty.
+  }
+
+  std::unique_ptr<impl::IIterator> implementation_;
+
+  /**
+   * Count the instances iterated thus far so that we can compare the iterators,
+   * or -1 if the iteration is done.
+   */
+  long index_;
+};
+
+bool operator==(const Iterator& a, const Iterator& b);
+
+bool operator!=(const Iterator& a, const Iterator& b);
+
+/**
+ * \brief Materialize the path that the \p iterator points to.
+ *
+ * We assume that you always want a copy of the path, rather than inspect
+ * the path during the iteration.
+ *
+ * \param iterator for which we want to materialize the path
+ * \return Path referring to the pointed instance
+ */
+Path MaterializePath(const Iterator& iterator);
+
+/**
+ * Build a facade over an instance to iterate over instances referenced from it.
+ */
+class IDescent {
+ public:
+  virtual Iterator begin() const = 0;
+  virtual const Iterator& end() const = 0;
+  virtual ~IDescent() = default;
+};  // class IDescent
+
+/**
+ * \brief Provide a recursive iterable over all the instances referenced from
+ * an instance.
+ *
+ * Please see the notes in the class Iterator regarding the constant reference to
+ * a shared pointer. In short, the instance should outlive the descent, so make
+ * sure you do not destroy it during the descent.
+ *
+ * Range-based loops should fit the vast majority of the use cases:
+ * \code
+ * std::shared_ptr<types::Environment> env = ...;
+ * for (
+ *   const std::shared_ptr<types::IClass>& instance
+ *   : Descent(env)
+ * ) {
+ *   do_something(instance);
+ * }
+ * \endcode
+ *
+ * \param that instance to be iterated over recursively
+ * \return Iterable over referenced instances
+ */
+class Descent : public IDescent {
+ public:
+  Descent(
+    std::shared_ptr<types::IClass> instance
+  );
+
+  Iterator begin() const override;
+  const Iterator& end() const override;
+
+  ~Descent() override = default;
+
+ private:
+  std::shared_ptr<types::IClass> instance_;
+};  // class Descent
+
+/**
+ * \brief Provide a non-recursive iterable over the instances referenced from
+ * an instance.
+ *
+ * Please see the notes in the class Iterator regarding the constant reference to
+ * a shared pointer. In short, the instance should outlive the descent, so make
+ * sure you do not destroy it during the descent.
+ *
+ * Range-based loops should fit the vast majority of the use cases:
+ * \code
+ * std::shared_ptr<types::Environment> env = ...;
+ * for (
+ *   const std::shared_ptr<types::IClass>& instance
+ *   : DescentOnce(env)
+ * ) {
+ *   do_something(instance);
+ * }
+ * \endcode
+ */
+class DescentOnce : public IDescent {
+ public:
+  DescentOnce(
+    std::shared_ptr<types::IClass> instance
+  );
+
+  Iterator begin() const override;
+  const Iterator& end() const override;
+
+  ~DescentOnce() override = default;
+
+ private:
+  std::shared_ptr<types::IClass> instance_;
+};  // class DescentOnce
+
+// endregion Iterators and descent
+
+}  // namespace iteration
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_ITERATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/jsonization.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/jsonization.hpp
new file mode 100644
index 000000000..92d14a07c
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/jsonization.hpp
@@ -0,0 +1,272 @@
+#ifndef DUMMY_JSONIZATION_GUARD_
+#define DUMMY_JSONIZATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/iteration.hpp"
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <nlohmann/json.hpp>
+
+#include <memory>
+#include <string>
+#include <utility>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup jsonization De/serialize instances from and to JSON.
+ * @{
+ */
+namespace jsonization {
+
+/**
+ * Represent a segment of a JSON path to some value.
+ */
+class ISegment {
+ public:
+  /**
+   * \brief Convert the segment to a string in a JSON path.
+   */
+  virtual std::wstring ToWstring() const = 0;
+
+  virtual std::unique_ptr<ISegment> Clone() const = 0;
+
+  virtual ~ISegment() = default;
+};  // class ISegment
+
+/**
+ * Represent a property access on a JSON path.
+ */
+struct PropertySegment : public ISegment {
+  /**
+   * Name of the property in a JSON object
+   */
+  std::wstring name;
+
+  PropertySegment(
+    std::wstring a_name
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~PropertySegment() override = default;
+};  // struct PropertySegment
+
+/**
+ * Represent an index access on a JSON path.
+ */
+struct IndexSegment : public ISegment {
+  /**
+   * Index of the value in an array.
+   */
+  size_t index;
+
+  explicit IndexSegment(
+    size_t an_index
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~IndexSegment() override = default;
+};  // struct IndexSegment
+
+/**
+ * Represent an access to a member of a JSON object whose key is known only at
+ * run time, such as a member of a JSON-able object, on a JSON path.
+ */
+struct KeySegment : public ISegment {
+  /**
+   * Key of the member in a JSON object
+   */
+  std::wstring key;
+
+  explicit KeySegment(
+    std::wstring a_key
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~KeySegment() override = default;
+};  // struct KeySegment
+
+/**
+ * Represent a JSON path to some value.
+ */
+struct Path {
+  std::deque<std::unique_ptr<ISegment> > segments;
+
+  Path();
+  Path(const Path& other);
+  Path(Path&& other);
+  Path& operator=(const Path& other);
+  Path& operator=(Path&& other);
+
+  std::wstring ToWstring() const;
+};  // struct Path
+
+// region De-serialization
+
+/**
+ * Represent a de-serialization error.
+ */
+struct DeserializationError {
+  /**
+   * Human-readable description of the error
+   */
+  std::wstring cause;
+
+  /**
+   * Path to the erroneous value
+   */
+  Path path;
+
+  explicit DeserializationError(std::wstring a_cause);
+  DeserializationError(std::wstring a_cause, Path a_path);
+};  // struct DeserializationError
+
+/**
+ * \brief Deserialize \p json value to an instance
+ * of types::IItem.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return The deserialized instance, or a de-serialization error, if any.
+ */
+common::expected<
+  std::shared_ptr<types::IItem>,
+  DeserializationError
+> ItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties = false
+);
+
+/**
+ * \brief Deserialize \p json value to an instance
+ * of types::ISomeItem.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return The deserialized instance, or a de-serialization error, if any.
+ */
+common::expected<
+  std::shared_ptr<types::ISomeItem>,
+  DeserializationError
+> SomeItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties = false
+);
+
+/**
+ * \brief Deserialize \p json value to an instance
+ * of types::ISpecialItem.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return The deserialized instance, or a de-serialization error, if any.
+ */
+common::expected<
+  std::shared_ptr<types::ISpecialItem>,
+  DeserializationError
+> SpecialItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties = false
+);
+
+/**
+ * \brief Deserialize \p json value to an instance
+ * of types::IContainer.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return The deserialized instance, or a de-serialization error, if any.
+ */
+common::expected<
+  std::shared_ptr<types::IContainer>,
+  DeserializationError
+> ContainerFrom(
+  const nlohmann::json& json,
+  bool additional_properties = false
+);
+
+/**
+ * \brief Deserialize \p json value to an instance
+ * of types::IWrapper.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return The deserialized instance, or a de-serialization error, if any.
+ */
+common::expected<
+  std::shared_ptr<types::IWrapper>,
+  DeserializationError
+> WrapperFrom(
+  const nlohmann::json& json,
+  bool additional_properties = false
+);
+
+// endregion Deserialization
+
+// region Serialization
+
+/**
+ * Represent an error in the serialization of an instance to JSON.
+ */
+class SerializationException : public std::exception {
+ public:
+  SerializationException(
+    std::wstring cause,
+    iteration::Path path
+  );
+
+  const char* what() const noexcept override;
+
+  const std::wstring& cause() const noexcept;
+  const iteration::Path& path() const noexcept;
+
+  ~SerializationException() noexcept override = default;
+
+ private:
+  const std::wstring cause_;
+  const iteration::Path path_;
+  const std::string msg_;
+};  // class SerializationException
+
+/**
+ * \brief Serialize \p that instance to a JSON value.
+ *
+ * \param that instance to be serialized
+ * \return The corresponding JSON value
+ * \throw \ref SerializationException if a value within \p that instance
+ * could not be serialized
+ */
+nlohmann::json Serialize(
+  const types::IClass& that
+);
+
+// endregion Serialization
+
+}  // namespace jsonization
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_JSONIZATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/pattern.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/pattern.hpp
new file mode 100644
index 000000000..5dc94a051
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/pattern.hpp
@@ -0,0 +1,34 @@
+#ifndef DUMMY_PATTERN_GUARD_
+#define DUMMY_PATTERN_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/revm.hpp"
+
+#pragma warning(push, 0)
+#include <memory>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup pattern Provide patterns to be matched using a multi-threaded virtual machine.
+ *
+ * The instructions should be supplied to dummy::revm::Match. While
+ * we could have theoretically included this code in verification, we decided to keep
+ * it separate for readability. You are not expected to use this module directly.
+ * @{
+ */
+namespace pattern {
+
+}  // namespace pattern
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_PATTERN_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/revm.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/revm.hpp
new file mode 100644
index 000000000..2d7dec68f
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/revm.hpp
@@ -0,0 +1,213 @@
+#ifndef DUMMY_REVM_GUARD_
+#define DUMMY_REVM_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#pragma warning(push, 0)
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup revm Match regular expressions using a multi-threaded virtual machine.
+ *
+ * The implementation in the standard library has exponential time complexity, so it was
+ * a major blocker for most of the practical inputs. For example, see this bug report:
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93502
+ *
+ * This implementation is based on Ken Thompson's approach which uses a virtual
+ * machine to match regular expressions. The original technique has been
+ * published in:
+ * Thompson, K., "Regular expression search algorithm", ACM 11(6) (June 1968)
+ *
+ * We followed a very clear and concise blog post which described in detail:
+ * https://swtch.com/~rsc/regexp/regexp2.html
+ *
+ * The ideas for additional instructions were taken from:
+ * https://www.codeproject.com/Articles/5256833/Regex-as-a-Tiny-Threaded-Virtual-Machine
+ * @{
+ */
+namespace revm {
+
+enum class InstructionKind : std::uint8_t {
+  Char,
+  Set,
+  NotSet,
+  Any,
+  Match,
+  Jump,
+  Split,
+  End
+};
+
+/**
+ * Represent an instruction of the virtual machine.
+ */
+struct Instruction {
+  // NOTE (mristin):
+  // We avoid RTTI for performance reasons, and use our own enumerator instead.
+  virtual InstructionKind kind() const = 0;
+
+  virtual ~Instruction() = default;
+};
+
+/**
+ * Match a single character.
+ *
+ * If the character on the String Pointer does not match the `character`, stop this
+ * thread as it failed. Otherwise, move the String Pointer to the next character,
+ * and the Program Counter to the next instruction.
+ */
+struct InstructionChar : Instruction {
+  wchar_t character;
+
+  explicit InstructionChar(wchar_t a_character);
+  InstructionKind kind() const override;
+  ~InstructionChar() override = default;
+};
+
+std::string to_string(const InstructionChar& instruction);
+
+/**
+ * Define a character range.
+ */
+struct Range {
+  wchar_t first;
+  wchar_t last;
+
+  Range(wchar_t a_first, wchar_t a_last);
+};
+
+std::string to_string(const Range& range);
+
+/**
+ * Check whether the character is in any of the given character ranges.
+ *
+ * @return true if the character is in any of the ranges
+ */
+bool CharacterInRanges(
+  const std::vector<Range>& ranges,
+  wchar_t character
+);
+
+/**
+ * Match a set of characters.
+ *
+ * If the character on the String Pointer *is not* in the given set, stop this
+ * thread as it failed. Otherwise, move the String Pointer to the next character,
+ * and the Program Counter to the next instruction.
+ */
+struct InstructionSet : Instruction {
+  std::vector<Range> ranges;
+
+  explicit InstructionSet(std::vector<Range> a_ranges);
+  InstructionKind kind() const override;
+  ~InstructionSet() override = default;
+};
+
+std::string to_string(const InstructionSet& instruction);
+
+/**
+ * Match an out-of-set character.
+ *
+ * If the character on the String Pointer *is* in the given set, stop this
+ * thread as it failed. Otherwise, move the String Pointer to the next character,
+ * and the Program Counter to the next instruction.
+ */
+struct InstructionNotSet : Instruction {
+  std::vector<Range> ranges;
+
+  explicit InstructionNotSet(std::vector<Range> a_ranges);
+  InstructionKind kind() const override;
+  ~InstructionNotSet() override = default;
+};
+
+std::string to_string(const InstructionNotSet& instruction);
+
+/**
+ * Match any character.
+ */
+struct InstructionAny : Instruction {
+  InstructionKind kind() const override;
+  ~InstructionAny() override = default;
+};
+
+std::string to_string(const InstructionAny&);
+
+/**
+ * Stop this thread and signal that we found a match.
+ */
+struct InstructionMatch : Instruction {
+  InstructionKind kind() const override;
+  ~InstructionMatch() override = default;
+};
+
+std::string to_string(const InstructionMatch&);
+
+/**
+ * Jump to the indicated position in the program.
+ */
+struct InstructionJump : Instruction {
+  size_t target;
+
+  explicit InstructionJump(size_t a_target);
+  InstructionKind kind() const override;
+  ~InstructionJump() override = default;
+};
+
+std::string to_string(const InstructionJump& instruction);
+
+/**
+ * Split the program in two threads, both jumping to different locations. The string
+ * pointer is kept as-is.
+ */
+struct InstructionSplit : Instruction {
+  size_t first_target;
+  size_t second_target;
+
+  explicit InstructionSplit(size_t a_first_target, size_t a_second_target);
+  InstructionKind kind() const override;
+  ~InstructionSplit() override = default;
+};
+
+std::string to_string(const InstructionSplit& instruction);
+
+/**
+ * Match the end-of-input.
+ */
+struct InstructionEnd : Instruction {
+  InstructionKind kind() const override;
+  ~InstructionEnd() override = default;
+};
+
+std::string to_string(const InstructionEnd&);
+
+std::string to_string(const Instruction& instruction);
+
+std::string to_string(
+  const std::vector<std::unique_ptr<Instruction> >& instructions
+);
+
+/**
+ * Try to match the program against the text.
+ * @return true if the text matches
+ */
+bool Match(
+  const std::vector<std::unique_ptr<Instruction> >& program,
+  const std::wstring& text
+);
+
+}  // namespace revm
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_REVM_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/stringification.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/stringification.hpp
new file mode 100644
index 000000000..66dfea760
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/stringification.hpp
@@ -0,0 +1,91 @@
+#ifndef DUMMY_STRINGIFICATION_GUARD_
+#define DUMMY_STRINGIFICATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <string>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup stringification Translate to strings, and, where applicable, from strings.
+ * @{
+ */
+namespace stringification {
+
+/**
+ * Try to parse the \p text as a model type literal.
+ *
+ * \param text to be parsed
+ * \return literal, or nothing, if \p text invalid
+ */
+common::optional<types::ModelType> ModelTypeFromString(
+  const std::string& text
+);
+
+/**
+ * Parse the \p text as a model type literal.
+ *
+ * \param text to be parsed
+ * \return literal
+ * \throw std::invalid_argument if \p text invalid
+ */
+types::ModelType MustModelTypeFromString(
+  const std::string& text
+);
+
+/**
+ * Translate the enumeration literal \p model_type to text.
+ *
+ * \param model_type to be converted into text
+ * \return text representation of \p model_type
+ * \throw std::invalid_argument if \p model_type invalid
+ */
+std::string to_string(
+  types::ModelType model_type
+);
+
+/**
+ * Encode the \p bytes with base64 to a std::string.
+ *
+ * \param bytes to be encoded
+ * \return base64-encoding of \p bytes
+ */
+std::string Base64Encode(
+  const std::vector<std::uint8_t>& bytes
+);
+
+/**
+ * Decode the \p the text with base64 to bytes.
+ *
+ * \remark \parblock
+ * We intentionally decode from std::string and *not* from std::wstring as
+ * the de/serialization libraries currently work only with UTF-8 encoded strings.
+ * \endparblock
+ *
+ * \param text to be decoded
+ * \return decoded bytes, or error message, if any.
+ */
+common::expected<
+  std::vector<std::uint8_t>,
+  std::string
+> Base64Decode(
+  const std::string& text
+);
+
+}  // namespace stringification
+}  // namespace dummy
+
+/**@}*/
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_STRINGIFICATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/types.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/types.hpp
new file mode 100644
index 000000000..04a9a21c2
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/types.hpp
@@ -0,0 +1,512 @@
+#ifndef DUMMY_TYPES_GUARD_
+#define DUMMY_TYPES_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+
+#pragma warning(push, 0)
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup types Define data structures corresponding to the meta-model.
+ * @{
+ */
+namespace types {
+
+// region Enumerations
+
+/**
+ * Enumerate the model types for faster type switches.
+ *
+ * For example, switch statements can be implemented as jump tables.
+ */
+enum class ModelType : std::uint32_t {
+  kSomeItem = 0,
+  kSpecialItem = 1,
+  kContainer = 2,
+  kWrapper = 3
+};
+
+// endregion Enumerations
+
+// region Forward declaration of interfaces
+
+// endregion Forward declaration of interfaces
+
+class IItem;
+
+class ISomeItem;
+
+class ISpecialItem;
+
+class IContainer;
+
+class IWrapper;
+
+// region Class interfaces
+
+/**
+ * Model the most general instance of the model.
+ */
+class IClass {
+ public:
+  /**
+   * Indicate the runtime model type.
+   */
+  virtual ModelType model_type() const = 0;
+  virtual ~IClass() = default;
+};
+
+class IItem
+    : virtual public IClass {
+ public:
+  virtual const std::wstring& name() const = 0;
+
+  virtual std::wstring& mutable_name() = 0;
+
+  virtual void set_name(
+    std::wstring value
+  ) = 0;
+
+  virtual const common::optional<std::wstring>& nickname() const = 0;
+
+  virtual common::optional<std::wstring>& mutable_nickname() = 0;
+
+  virtual void set_nickname(
+    common::optional<std::wstring> value
+  ) = 0;
+
+  virtual ~IItem() = default;
+};
+
+class ISomeItem
+    : virtual public IItem {
+ public:
+  virtual ~ISomeItem() = default;
+};
+
+class ISpecialItem
+    : virtual public ISomeItem {
+ public:
+  virtual int64_t level() const = 0;
+
+  virtual int64_t& mutable_level() = 0;
+
+  virtual void set_level(
+    int64_t value
+  ) = 0;
+
+  virtual ~ISpecialItem() = default;
+};
+
+class IContainer
+    : virtual public IClass {
+ public:
+  virtual const std::vector<
+    std::shared_ptr<IItem>
+  >& items() const = 0;
+
+  virtual std::vector<
+    std::shared_ptr<IItem>
+  >& mutable_items() = 0;
+
+  virtual void set_items(
+    std::vector<
+      std::shared_ptr<IItem>
+    > value
+  ) = 0;
+
+  virtual const std::vector<
+    std::shared_ptr<ISomeItem>
+  >& some_items() const = 0;
+
+  virtual std::vector<
+    std::shared_ptr<ISomeItem>
+  >& mutable_some_items() = 0;
+
+  virtual void set_some_items(
+    std::vector<
+      std::shared_ptr<ISomeItem>
+    > value
+  ) = 0;
+
+  virtual const common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  >& special_items() const = 0;
+
+  virtual common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  >& mutable_special_items() = 0;
+
+  virtual void set_special_items(
+    common::optional<
+      std::vector<
+        std::shared_ptr<ISpecialItem>
+      >
+    > value
+  ) = 0;
+
+  /// \brief Count the \p items.
+  ///
+  /// The arguments of the methods are never generic, so only the sequences of
+  /// IItem can be passed to it, but not the sequences of
+  /// the descendants.
+  virtual int64_t CountItems(
+    const std::vector<
+      std::shared_ptr<IItem>
+    >& items
+  ) const = 0;
+
+  virtual ~IContainer() = default;
+};
+
+class IWrapper
+    : virtual public IClass {
+ public:
+  virtual const std::shared_ptr<IContainer>& container() const = 0;
+
+  virtual std::shared_ptr<IContainer>& mutable_container() = 0;
+
+  virtual void set_container(
+    std::shared_ptr<IContainer> value
+  ) = 0;
+
+  virtual ~IWrapper() = default;
+};
+
+// endregion
+
+// region Definitions of concrete classes
+
+class SomeItem
+    : public ISomeItem {
+ public:
+  explicit SomeItem(
+    std::wstring name,
+    common::optional<std::wstring> nickname = common::nullopt
+  );
+
+  ModelType model_type() const override;
+
+  // region Get and set name_
+
+  const std::wstring& name() const override;
+
+  std::wstring& mutable_name() override;
+
+  void set_name(
+    std::wstring value
+  ) override;
+
+  // endregion
+
+  // region Get and set nickname_
+
+  const common::optional<std::wstring>& nickname() const override;
+
+  common::optional<std::wstring>& mutable_nickname() override;
+
+  void set_nickname(
+    common::optional<std::wstring> value
+  ) override;
+
+  // endregion
+
+  ~SomeItem() override = default;
+
+ private:
+  std::wstring name_;
+
+  common::optional<std::wstring> nickname_;
+};
+
+class SpecialItem
+    : public ISpecialItem {
+ public:
+  SpecialItem(
+    std::wstring name,
+    int64_t level,
+    common::optional<std::wstring> nickname = common::nullopt
+  );
+
+  ModelType model_type() const override;
+
+  // region Get and set name_
+
+  const std::wstring& name() const override;
+
+  std::wstring& mutable_name() override;
+
+  void set_name(
+    std::wstring value
+  ) override;
+
+  // endregion
+
+  // region Get and set nickname_
+
+  const common::optional<std::wstring>& nickname() const override;
+
+  common::optional<std::wstring>& mutable_nickname() override;
+
+  void set_nickname(
+    common::optional<std::wstring> value
+  ) override;
+
+  // endregion
+
+  // region Get and set level_
+
+  int64_t level() const override;
+
+  int64_t& mutable_level() override;
+
+  void set_level(
+    int64_t value
+  ) override;
+
+  // endregion
+
+  ~SpecialItem() override = default;
+
+ private:
+  std::wstring name_;
+
+  common::optional<std::wstring> nickname_;
+
+  int64_t level_;
+};
+
+class Container
+    : public IContainer {
+ public:
+  Container(
+    std::vector<
+      std::shared_ptr<IItem>
+    > items,
+    std::vector<
+      std::shared_ptr<ISomeItem>
+    > some_items,
+    common::optional<
+      std::vector<
+        std::shared_ptr<ISpecialItem>
+      >
+    > special_items = common::nullopt
+  );
+
+  ModelType model_type() const override;
+
+  // region Get and set items_
+
+  const std::vector<
+    std::shared_ptr<IItem>
+  >& items() const override;
+
+  std::vector<
+    std::shared_ptr<IItem>
+  >& mutable_items() override;
+
+  void set_items(
+    std::vector<
+      std::shared_ptr<IItem>
+    > value
+  ) override;
+
+  // endregion
+
+  // region Get and set some_items_
+
+  const std::vector<
+    std::shared_ptr<ISomeItem>
+  >& some_items() const override;
+
+  std::vector<
+    std::shared_ptr<ISomeItem>
+  >& mutable_some_items() override;
+
+  void set_some_items(
+    std::vector<
+      std::shared_ptr<ISomeItem>
+    > value
+  ) override;
+
+  // endregion
+
+  // region Get and set special_items_
+
+  const common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  >& special_items() const override;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  >& mutable_special_items() override;
+
+  void set_special_items(
+    common::optional<
+      std::vector<
+        std::shared_ptr<ISpecialItem>
+      >
+    > value
+  ) override;
+
+  // endregion
+
+  int64_t CountItems(
+    const std::vector<
+      std::shared_ptr<IItem>
+    >& items
+  ) const override;
+
+  ~Container() override = default;
+
+ private:
+  std::vector<
+    std::shared_ptr<IItem>
+  > items_;
+
+  std::vector<
+    std::shared_ptr<ISomeItem>
+  > some_items_;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  > special_items_;
+};
+
+class Wrapper
+    : public IWrapper {
+ public:
+  explicit Wrapper(
+    std::shared_ptr<IContainer> container
+  );
+
+  ModelType model_type() const override;
+
+  // region Get and set container_
+
+  const std::shared_ptr<IContainer>& container() const override;
+
+  std::shared_ptr<IContainer>& mutable_container() override;
+
+  void set_container(
+    std::shared_ptr<IContainer> value
+  ) override;
+
+  // endregion
+
+  ~Wrapper() override = default;
+
+ private:
+  std::shared_ptr<IContainer> container_;
+};
+
+// endregion
+
+// region Is-a functions
+
+/**
+ * \brief Check whether \p that instance is of runtime type
+ * \ref IItem.
+ *
+ * We use `IClass::model_type` to determine the runtime type, which is
+ * a bit faster than native C++'s RTTI.
+ *
+ * \param that instance to check for runtime type
+ * \return `true` if \p that instance is indeed
+ * an instance of \ref IItem
+ */
+bool IsItem(
+  const IClass& that
+);
+
+/**
+ * \brief Check whether \p that instance is of runtime type
+ * \ref ISomeItem.
+ *
+ * We use `IClass::model_type` to determine the runtime type, which is
+ * a bit faster than native C++'s RTTI.
+ *
+ * \param that instance to check for runtime type
+ * \return `true` if \p that instance is indeed
+ * an instance of \ref ISomeItem
+ */
+bool IsSomeItem(
+  const IClass& that
+);
+
+/**
+ * \brief Check whether \p that instance is of runtime type
+ * \ref ISpecialItem.
+ *
+ * We use `IClass::model_type` to determine the runtime type, which is
+ * a bit faster than native C++'s RTTI.
+ *
+ * \param that instance to check for runtime type
+ * \return `true` if \p that instance is indeed
+ * an instance of \ref ISpecialItem
+ */
+bool IsSpecialItem(
+  const IClass& that
+);
+
+/**
+ * \brief Check whether \p that instance is of runtime type
+ * \ref IContainer.
+ *
+ * We use `IClass::model_type` to determine the runtime type, which is
+ * a bit faster than native C++'s RTTI.
+ *
+ * \param that instance to check for runtime type
+ * \return `true` if \p that instance is indeed
+ * an instance of \ref IContainer
+ */
+bool IsContainer(
+  const IClass& that
+);
+
+/**
+ * \brief Check whether \p that instance is of runtime type
+ * \ref IWrapper.
+ *
+ * We use `IClass::model_type` to determine the runtime type, which is
+ * a bit faster than native C++'s RTTI.
+ *
+ * \param that instance to check for runtime type
+ * \return `true` if \p that instance is indeed
+ * an instance of \ref IWrapper
+ */
+bool IsWrapper(
+  const IClass& that
+);
+
+// endregion Is-a functions
+
+}  // namespace types
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_TYPES_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/verification.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/verification.hpp
new file mode 100644
index 000000000..97dd9b21f
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/verification.hpp
@@ -0,0 +1,884 @@
+#ifndef DUMMY_VERIFICATION_GUARD_
+#define DUMMY_VERIFICATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/constants.hpp"
+#include "dummy/iteration.hpp"
+#include "dummy/pattern.hpp"
+#include "dummy/stringification.hpp"
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <memory>
+#include <set>
+#include <type_traits>
+#include <unordered_set>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup verification Verify that instances conform to the meta-model constraints.
+ * @{
+ */
+namespace verification {
+
+// region Forward declarations
+class Iterator;
+class IVerification;
+
+namespace impl {
+class IVerificator;
+}  // namespace impl
+// endregion Forward declarations
+
+/**
+ * Represent a verification error in an instance.
+ */
+struct Error {
+  /**
+   * Human-readable description of the error
+   */
+  std::wstring cause;
+
+  /**
+   * Path to the erroneous value
+   */
+  iteration::Path path;
+
+  explicit Error(std::wstring a_cause);
+  Error(std::wstring a_cause, iteration::Path a_path);
+};  // struct Error
+
+/**
+ * \brief Iterate over the verification errors.
+ *
+ * The user is expected to take ownership of the errors if they need to be further
+ * processed.
+ *
+ * Unlike STL, this is <em>not</em> a light-weight iterator. We implement
+ * a "yielding" iterator which keeps where it stopped in the model, so that
+ * it looks for the next error only when you move it.
+ *
+ * This means that copy-construction and equality comparisons are much more heavy-weight
+ * than you'd usually expect from an STL iterator. For example, if you want to sort
+ * the errors by some criterion, you are most probably faster if you populate a vector,
+ * and then sort the vector.
+ *
+ * Also, given that this iterator is not light-weight, you should in almost all cases
+ * avoid the postfix increment (it++) and prefer the prefix one (++it) as the postfix
+ * increment would create an iterator copy every time.
+ *
+ * We follow the C++ standard, and assume that comparison between the two iterators
+ * over two different collections results in undefined behavior. See
+ * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2948.html and
+ * https://stackoverflow.com/questions/4657513/comparing-iterators-from-different-containers.
+ */
+class Iterator {
+  using iterator_category = std::forward_iterator_tag;
+  /// The difference is meaningless, but has to be defined.
+  using difference_type = std::ptrdiff_t;
+  using value_type = Error;
+  using pointer = const Error*;
+  using reference = const Error&;
+
+ public:
+  explicit Iterator(
+    std::unique_ptr<impl::IVerificator> verificator
+  ) :
+  verificator_(std::move(verificator)) {
+      // Intentionally empty.
+  }
+
+  Iterator(const Iterator& other);
+  Iterator(Iterator&& other);
+
+  Iterator& operator=(const Iterator& other);
+  Iterator& operator=(Iterator&& other);
+
+  reference operator*() const;
+  pointer operator->() const;
+
+  // Prefix increment
+  Iterator& operator++();
+
+  // Postfix increment
+  Iterator operator++(int);
+
+  friend bool operator==(const Iterator& a, const Iterator& b);
+  friend bool operator!=(const Iterator& a, const Iterator& b);
+
+ private:
+  std::unique_ptr<impl::IVerificator> verificator_;
+};
+
+bool operator==(const Iterator& a, const Iterator& b);
+
+bool operator!=(const Iterator& a, const Iterator& b);
+
+/// \cond HIDDEN
+namespace impl {
+class IVerificator {
+ public:
+  virtual void Start() = 0;
+  virtual void Next() = 0;
+  virtual bool Done() const = 0;
+
+  virtual const Error& Get() const = 0;
+  virtual Error& GetMutable() = 0;
+  virtual long Index() const = 0;
+
+  virtual std::unique_ptr<IVerificator> Clone() const = 0;
+
+  virtual ~IVerificator() = default;
+};  // class IVerificator
+}  // namespace impl
+/// \endcond
+
+class IVerification {
+ public:
+  virtual Iterator begin() const = 0;
+  virtual const Iterator& end() const = 0;
+  virtual ~IVerification() = default;
+};  // class IVerification
+
+/**
+ * \brief Verify that the instance conforms to the meta-model constraints.
+ *
+ * Do not proceed to verify the instances referenced from
+ * the given instance.
+ *
+ * Range-based loops should fit the vast majority of the use cases:
+ * \code
+ * std::shared_ptr<types::Environment> env = ...;
+ * for (const Error& error : NonRecursiveVerification(env)) {
+ *   report_somehow(error);
+ * }
+ * \endcode
+ *
+ * We use const references to shared pointers here for efficiency. Since
+ * we do not make a copy of \p that shared pointer, it is very important that
+ * the given shared pointer outlives the verification, lest cause undefined behavior.
+ * See these StackOverflow questions:
+ * * https://stackoverflow.com/questions/12002480/passing-stdshared-ptr-to-constructors/12002668#12002668
+ * * https://stackoverflow.com/questions/3310737/should-we-pass-a-shared-ptr-by-reference-or-by-value
+ * * https://stackoverflow.com/questions/37610494/passing-const-shared-ptrt-versus-just-shared-ptrt-as-parameter
+ */
+class NonRecursiveVerification : public IVerification {
+ public:
+  NonRecursiveVerification(
+    const std::shared_ptr<types::IClass>& instance
+  );
+
+  Iterator begin() const override;
+  const Iterator& end() const override;
+
+  ~NonRecursiveVerification() override = default;
+ private:
+  const std::shared_ptr<types::IClass>& instance_;
+};  // class NonRecursiveVerification
+
+/**
+ * \brief Verify that the instance conforms to the meta-model constraints.
+ *
+ * Also verify recursively all the instances referenced from
+ * the given instance.
+ *
+ * Range-based loops should fit the vast majority of the use cases:
+ * \code
+ * std::shared_ptr<types::Environment> env = ...;
+ * for (const Error& error : RecursiveVerification(env)) {
+ *   report_somehow(error);
+ * }
+ * \endcode
+ *
+ * We use const references to shared pointers here for efficiency. Since
+ * we do not make a copy of \p that shared pointer, it is very important that
+ * the given shared pointer outlives the verification, lest cause undefined behavior.
+ * See these StackOverflow questions:
+ * * https://stackoverflow.com/questions/12002480/passing-stdshared-ptr-to-constructors/12002668#12002668
+ * * https://stackoverflow.com/questions/3310737/should-we-pass-a-shared-ptr-by-reference-or-by-value
+ * * https://stackoverflow.com/questions/37610494/passing-const-shared-ptrt-versus-just-shared-ptrt-as-parameter
+ */
+class RecursiveVerification : public IVerification {
+ public:
+  RecursiveVerification(
+    const std::shared_ptr<types::IClass>& instance
+  );
+
+  Iterator begin() const override;
+  const Iterator& end() const override;
+
+  ~RecursiveVerification() override = default;
+ private:
+  const std::shared_ptr<types::IClass>& instance_;
+};  // class RecursiveVerification
+
+// region Verification functions
+
+/// \brief Check that the names of the \p items are unique.
+///
+/// The \p items are a generic sequence, so the sequences of
+/// the descendants of types::IItem can be passed without a copy.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool NamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Iterate over a generic sequence in a generator.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool NamesAreNonEmpty(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Narrow the items of a generic sequence in a generator.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool SomeSpecialItemHasLevel(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Index a generic sequence, and narrow the item.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool FirstIsSpecial(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Check that the nicknames of the \p items are unique, if specified.
+///
+/// This mirrors the body of `ID_shorts_are_unique` in aas-core-meta V3.2:
+/// a local variable takes an optional property of an item of a generic sequence,
+/// and the loop continues if it is None.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool NicknamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Narrow the loop variable over a generic sequence in a for-loop.
+///
+/// The loop variable is of the type parameter in Go, so the down-cast needs to
+/// go through `any(...)`, and of the template parameter in C++.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool LevelsOfSpecialItemsArePositive(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Narrow an immutable local variable which holds an item of a generic sequence.
+///
+/// In contrast to FirstIsSpecial, the local variable is annotated, so
+/// it is of the parent class instead of the type parameter. Hence, Go down-casts
+/// it without `any(...)`, and C++ binds the item to a constant reference to
+/// the shared pointer of the parent class.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool LastIsSpecial(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Mix two generic sequences with an argument which is not generic.
+///
+/// The names must differ, except for the \p shared_name, which may repeat.
+///
+/// Go declares two type parameters, and C++ two template parameters. The nested
+/// generators iterate over two different generic sequences, so their variables
+/// are of two different type parameters.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+///
+/// \tparam OtherItemsT type of the items of \p other_items, types::ISomeItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT,
+  typename OtherItemsT
+>
+bool NamesAreDisjoint(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const std::vector<
+    std::shared_ptr<OtherItemsT>
+  >& other_items,
+  const std::wstring& shared_name
+);
+
+/// \brief Use the immutable aliases of the generic sequences.
+///
+/// An immutable alias of the very same type shares the type annotation of
+/// the aliased generic sequence, so it is a generic sequence itself. Go declares
+/// the alias with the type parameter, C++ with the template parameter, while C#
+/// and Java infer its type with `var`. The `alias_of_alias` aliases an alias,
+/// and the `optional_alias` aliases an optional generic sequence.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+///
+/// \tparam OptionalItemsT type of the items of \p optional_items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT,
+  typename OptionalItemsT
+>
+bool AliasedNamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const common::optional<
+    std::vector<
+      std::shared_ptr<OptionalItemsT>
+    >
+  >& optional_items
+);
+
+/// \brief Look up an instance of a descendant in a generic sequence.
+///
+/// Go compares the instances as `any`'s, as the items are of the type parameter,
+/// and C++ converts the member to the shared pointer of types::IItem so that
+/// the raw pointers are comparable for any template parameter.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool ContainsSomeItem(
+  const std::shared_ptr<types::ISomeItem>& some_item,
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+);
+
+/// \brief Look up the items of a generic sequence in another generic sequence.
+///
+/// The member and the items are of two different type parameters.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+///
+/// \tparam OtherItemsT type of the items of \p other_items, types::ISomeItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT,
+  typename OtherItemsT
+>
+bool ItemsOverlap(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const std::vector<
+    std::shared_ptr<OtherItemsT>
+  >& other_items
+);
+
+/// \brief Look up an instance in a sequence which is not generic.
+///
+/// The types::ISpecialItem has no descendants, so the \p items are not
+/// a generic sequence, but Go still compares the instances as `any`'s.
+bool ContainsSpecialItem(
+  const std::shared_ptr<types::ISpecialItem>& special_item,
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& items
+);
+
+/// \brief Pass the local variables on to generic sequences.
+///
+/// The `some_items` is a read-only alias without an annotation, while
+/// the `all_some_items` is an immutable local variable declared with
+/// `Final[...]`. Both hold the sequences of types::ISomeItem, and are passed
+/// on to the generic sequences of types::IItem, required as well as optional.
+bool ContainerNamesAreUnique(
+  const std::shared_ptr<types::IContainer>& container
+);
+
+/// \brief Pass an optional generic sequence on to a generic sequence.
+///
+/// \tparam ItemsT type of the items of \p items, types::IItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename ItemsT
+>
+bool OptionalNamesAreUnique(
+  const common::optional<
+    std::vector<
+      std::shared_ptr<ItemsT>
+    >
+  >& items
+);
+
+/// \brief Pass the generic sequences of the descendants on.
+///
+/// The \p some_items are passed on as a required and as an optional
+/// sequence of the parent class, while the \p special_items are passed on
+/// as an optional sequence and, once narrowed, as a required sequence of the parent
+/// class of the parent class.
+///
+/// \tparam SomeItemsT type of the items of \p some_items, types::ISomeItem or one of its descendants, so that the vectors of the descendants can be passed without a copy, as std::vector is invariant
+template<
+  typename SomeItemsT
+>
+bool SomeNamesAreUnique(
+  const std::vector<
+    std::shared_ptr<SomeItemsT>
+  >& some_items,
+  const common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& special_items
+);
+
+/// \brief Check that the levels are positive.
+///
+/// The types::ISpecialItem has no descendants, so the \p items are not
+/// a generic sequence.
+bool LevelsArePositive(
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& items
+);
+
+// endregion Verification functions
+
+// region Definitions of generic verification functions
+
+template<
+  typename ItemsT
+>
+bool NamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  std::unordered_set<std::wstring> name_set = std::unordered_set<std::wstring>();
+  for (const std::shared_ptr<ItemsT>& item : items) {
+    if (name_set.find(item->name()) != name_set.end()) {
+      return false;
+    }
+    name_set.insert(item->name());
+  }
+  return true;
+}
+
+template<
+  typename ItemsT
+>
+bool NamesAreNonEmpty(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  return (
+    common::All(
+      [&](const std::shared_ptr<ItemsT>& item) -> bool {
+        return common::LenStr(item->name()) > 0;
+      },
+      items
+    )
+  );
+}
+
+template<
+  typename ItemsT
+>
+bool SomeSpecialItemHasLevel(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  return (
+    common::Some(
+      [&](const std::shared_ptr<ItemsT>& item) -> bool {
+        return (
+          types::IsSpecialItem(*item)
+          && std::dynamic_pointer_cast<types::ISpecialItem>(item)->level() > 0
+        );
+      },
+      items
+    )
+  );
+}
+
+template<
+  typename ItemsT
+>
+bool FirstIsSpecial(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  if (items.size() == 0) {
+    return false;
+  }
+  auto first = items.at(0);
+  if (types::IsSpecialItem(*first)) {
+    return (
+      std::dynamic_pointer_cast<types::ISpecialItem>(first)->level() > 0
+    );
+  }
+  return false;
+}
+
+template<
+  typename ItemsT
+>
+bool NicknamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  std::unordered_set<std::wstring> nickname_set = std::unordered_set<std::wstring>();
+  for (const std::shared_ptr<ItemsT>& item : items) {
+    auto nickname = item->nickname();
+    if (!(nickname.has_value())) {
+      continue;
+    }
+    if (nickname_set.find((*nickname)) != nickname_set.end()) {
+      return false;
+    }
+    nickname_set.insert((*nickname));
+  }
+  return true;
+}
+
+template<
+  typename ItemsT
+>
+bool LevelsOfSpecialItemsArePositive(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  for (const std::shared_ptr<ItemsT>& item : items) {
+    if (types::IsSpecialItem(*item)) {
+      if (std::dynamic_pointer_cast<types::ISpecialItem>(item)->level() <= 0) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+template<
+  typename ItemsT
+>
+bool LastIsSpecial(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  if (items.size() == 0) {
+    return false;
+  }
+  const std::shared_ptr<types::IItem> last = items.at(items.size() - (1));
+  if (types::IsSpecialItem(*last)) {
+    return (
+      std::dynamic_pointer_cast<types::ISpecialItem>(last)->level() > 0
+    );
+  }
+  return false;
+}
+
+template<
+  typename ItemsT,
+  typename OtherItemsT
+>
+bool NamesAreDisjoint(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const std::vector<
+    std::shared_ptr<OtherItemsT>
+  >& other_items,
+  const std::wstring& shared_name
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  static_assert(
+    std::is_base_of<types::ISomeItem, OtherItemsT>::value,
+    "Expected the items of other_items to be instances of types::ISomeItem"
+  );
+  return (
+    common::All(
+      [&](const std::shared_ptr<ItemsT>& item) -> bool {
+        return common::All(
+          [&](const std::shared_ptr<OtherItemsT>& other_item) -> bool {
+            return (
+              item->name() != other_item->name()
+              || item->name() == shared_name
+            );
+          },
+          other_items
+        );
+      },
+      items
+    )
+  );
+}
+
+template<
+  typename ItemsT,
+  typename OptionalItemsT
+>
+bool AliasedNamesAreUnique(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const common::optional<
+    std::vector<
+      std::shared_ptr<OptionalItemsT>
+    >
+  >& optional_items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  static_assert(
+    std::is_base_of<types::IItem, OptionalItemsT>::value,
+    "Expected the items of optional_items to be instances of types::IItem"
+  );
+  const std::vector<std::shared_ptr<ItemsT> >& alias = items;
+  const std::vector<std::shared_ptr<ItemsT> >& alias_of_alias = alias;
+  const common::optional<std::vector<std::shared_ptr<OptionalItemsT> > >& optional_alias = optional_items;
+  for (const std::shared_ptr<ItemsT>& item : alias) {
+    if (types::IsSpecialItem(*item)) {
+      if (std::dynamic_pointer_cast<types::ISpecialItem>(item)->level() <= 0) {
+        return false;
+      }
+    }
+  }
+  return (
+    (
+      common::All(
+        [&](const std::shared_ptr<ItemsT>& item) -> bool {
+          return common::LenStr(item->name()) > 0;
+        },
+        alias_of_alias
+      )
+      && NamesAreUnique(
+        alias_of_alias
+      )
+      && OptionalNamesAreUnique(
+        optional_alias
+      )
+      && (
+        (
+          (!(optional_alias.has_value()))
+          || NamesAreUnique(
+            (*optional_alias)
+          )
+        )
+      )
+    )
+  );
+}
+
+template<
+  typename ItemsT
+>
+bool ContainsSomeItem(
+  const std::shared_ptr<types::ISomeItem>& some_item,
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  return (
+    common::Contains(
+      items,
+      std::shared_ptr<types::IItem>(
+        some_item
+      )
+    )
+  );
+}
+
+template<
+  typename ItemsT,
+  typename OtherItemsT
+>
+bool ItemsOverlap(
+  const std::vector<
+    std::shared_ptr<ItemsT>
+  >& items,
+  const std::vector<
+    std::shared_ptr<OtherItemsT>
+  >& other_items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  static_assert(
+    std::is_base_of<types::ISomeItem, OtherItemsT>::value,
+    "Expected the items of other_items to be instances of types::ISomeItem"
+  );
+  return (
+    common::Some(
+      [&](const std::shared_ptr<OtherItemsT>& other_item) -> bool {
+        return common::Contains(
+          items,
+          std::shared_ptr<types::IItem>(
+            other_item
+          )
+        );
+      },
+      other_items
+    )
+  );
+}
+
+template<
+  typename ItemsT
+>
+bool OptionalNamesAreUnique(
+  const common::optional<
+    std::vector<
+      std::shared_ptr<ItemsT>
+    >
+  >& items
+) {
+  static_assert(
+    std::is_base_of<types::IItem, ItemsT>::value,
+    "Expected the items of items to be instances of types::IItem"
+  );
+  return (
+    (
+      (!(items.has_value()))
+      || NamesAreUnique(
+        (*items)
+      )
+    )
+  );
+}
+
+template<
+  typename SomeItemsT
+>
+bool SomeNamesAreUnique(
+  const std::vector<
+    std::shared_ptr<SomeItemsT>
+  >& some_items,
+  const common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& special_items
+) {
+  static_assert(
+    std::is_base_of<types::ISomeItem, SomeItemsT>::value,
+    "Expected the items of some_items to be instances of types::ISomeItem"
+  );
+  return (
+    (
+      NamesAreUnique(
+        some_items
+      )
+      && OptionalNamesAreUnique(
+        common::make_optional(
+          some_items
+        )
+      )
+      && OptionalNamesAreUnique(
+        special_items
+      )
+      && OptionalNamesAreUnique(
+        common::optional<
+          std::vector<
+            std::shared_ptr<types::IItem>
+          >
+        >()
+      )
+      && (
+        (
+          (!(special_items.has_value()))
+          || NamesAreUnique(
+            (*special_items)
+          )
+        )
+      )
+    )
+  );
+}
+
+// endregion Definitions of generic verification functions
+
+}  // namespace verification
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_VERIFICATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/visitation.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/visitation.hpp
new file mode 100644
index 000000000..9b729636a
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/visitation.hpp
@@ -0,0 +1,103 @@
+#ifndef DUMMY_VISITATION_GUARD_
+#define DUMMY_VISITATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/types.hpp"
+
+namespace dummy {
+
+/**
+ * \defgroup visitation Iterate and modify instances through visitors.
+ * @{
+ */
+namespace visitation {
+
+/**
+ * Provide an interface for a recursive mutating visitor on an instance.
+ */
+class IVisitor {
+ public:
+  /**
+   * Visit \p that instance and recursively visit all the instances
+   * referenced from \p that instance.
+   *
+   * We use const references to shared pointers here for efficiency in case you want,
+   * say, to share ownership over instances in your own external containers. Since
+   * we do not make copies of the shared pointers, it is very important that
+   * the given shared pointers outlive the visitor, lest cause undefined behavior.
+   * See these StackOverflow questions:
+   * * https://stackoverflow.com/questions/12002480/passing-stdshared-ptr-to-constructors/12002668#12002668
+   * * https://stackoverflow.com/questions/3310737/should-we-pass-a-shared-ptr-by-reference-or-by-value
+   * * https://stackoverflow.com/questions/37610494/passing-const-shared-ptrt-versus-just-shared-ptrt-as-parameter
+   *
+   * Changing the references during the visitation results in undefined
+   * behavior. This follows how STL deals with modifications to containers, see:
+   * https://stackoverflow.com/questions/6438086/iterator-invalidation-rules-for-c-containers
+   *
+   * \param that instance to be visited recursively
+   */
+  virtual void Visit(const std::shared_ptr<types::IClass>& that) = 0;
+  virtual ~IVisitor() = default;
+
+ protected:
+  virtual void VisitSomeItem(
+    const std::shared_ptr<types::ISomeItem>& that
+  ) = 0;
+  virtual void VisitSpecialItem(
+    const std::shared_ptr<types::ISpecialItem>& that
+  ) = 0;
+  virtual void VisitContainer(
+    const std::shared_ptr<types::IContainer>& that
+  ) = 0;
+  virtual void VisitWrapper(
+    const std::shared_ptr<types::IWrapper>& that
+  ) = 0;
+};  // class IVisitor
+
+/**
+ * Provide an abstract recursive mutating visitor on an instance.
+ */
+class AbstractVisitor
+    : public IVisitor {
+ public:
+  void Visit(const std::shared_ptr<types::IClass>& that) override;
+  ~AbstractVisitor() override = default;
+};  // class AbstractVisitor
+
+/**
+ * \brief Provide a mutating, recursive and no-op visitor on an instance.
+ *
+ * Usually, you want to inherit from this visitor and override one or more of its
+ * visitation methods.
+ */
+class PassThroughVisitor
+    : public AbstractVisitor {
+ public:
+  ~PassThroughVisitor() override = default;
+
+ protected:
+  void VisitSomeItem(
+    const std::shared_ptr<types::ISomeItem>& that
+  ) override;
+  void VisitSpecialItem(
+    const std::shared_ptr<types::ISpecialItem>& that
+  ) override;
+  void VisitContainer(
+    const std::shared_ptr<types::IContainer>& that
+  ) override;
+  void VisitWrapper(
+    const std::shared_ptr<types::IWrapper>& that
+  ) override;
+};  // class PassThroughVisitor
+
+}  // namespace visitation
+/**@*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_VISITATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/wstringification.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/wstringification.hpp
new file mode 100644
index 000000000..b5d9042c7
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/wstringification.hpp
@@ -0,0 +1,63 @@
+#ifndef DUMMY_WSTRINGIFICATION_GUARD_
+#define DUMMY_WSTRINGIFICATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/types.hpp"
+
+#pragma warning(push, 0)
+#include <string>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup wstringification De/wstringify to and from wstrings (where applicable).
+ * @{
+ */
+namespace wstringification {
+
+/**
+ * Try to parse the \p text as a model type literal.
+ *
+ * \param text to be parsed
+ * \return literal, or nothing, if \p text invalid
+ */
+common::optional<types::ModelType> ModelTypeFromWstring(
+  const std::wstring& text
+);
+
+/**
+ * Parse the \p text as a model type literal.
+ *
+ * \param text to be parsed
+ * \return literal
+ * \throw std::invalid_argument if \p text invalid
+ */
+types::ModelType MustModelTypeFromWstring(
+  const std::wstring& text
+);
+
+/**
+ * Translate the enumeration literal \p model_type to text.
+ *
+ * \param model_type to be converted into text
+ * \return text representation of \p model_type
+ * \throw std::invalid_argument if \p model_type invalid
+ */
+std::wstring to_wstring(
+  types::ModelType model_type
+);
+
+}  // namespace wstringification
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_WSTRINGIFICATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xml_path.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xml_path.hpp
new file mode 100644
index 000000000..ce72feb1f
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xml_path.hpp
@@ -0,0 +1,136 @@
+#ifndef DUMMY_XML_PATH_GUARD_
+#define DUMMY_XML_PATH_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+
+#pragma warning(push, 0)
+#include <deque>
+#include <memory>
+#include <string>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup xml_path Report where in an XML document an error occurred.
+ * @{
+ */
+namespace xml_path {
+
+/**
+ * Represent a segment of an XPath to an erroneous value.
+ */
+class ISegment {
+ public:
+  /**
+   * \brief Convert the segment to a string in an XPath.
+   *
+   * The result is escaped such that it can be directly inserted
+   * into an XPath.
+   */
+  virtual std::wstring ToWstring() const = 0;
+
+  virtual std::unique_ptr<ISegment> Clone() const = 0;
+
+  virtual ~ISegment() = default;
+};  // class ISegment
+
+/**
+ * Represent an element on an XPath to the erroneous value.
+ */
+struct ElementSegment : public ISegment {
+  /**
+   * \brief Name of the XML element, without the namespace
+   *
+   * We deliberately omit the namespace in the tag names. If you want to actually
+   * query with the resulting XPath, you have to insert the namespaces manually.
+   * We did not know how to include the namespace in a meaningful way, as XPath
+   * assumes namespace prefixes to be defined <em>outside</em> of the document.
+   * At least the path thus rendered is informative, and you should be able to
+   * descend it manually.
+   */
+  std::wstring name;
+
+  ElementSegment(
+    std::wstring a_name
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~ElementSegment() override = default;
+};  // struct ElementSegment
+
+/**
+ * \brief Represent a member of a struct on an XPath to the erroneous value.
+ *
+ * A struct holds its members' names in a ``<name>`` child element instead of
+ * an attribute, so we have to match on that child element.
+ */
+struct MemberSegment : public ISegment {
+  /**
+   * Name of the member
+   */
+  std::wstring name;
+
+  explicit MemberSegment(
+    std::wstring a_name
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~MemberSegment() override = default;
+};  // struct MemberSegment
+
+/**
+ * Represent an element in a sequence on an XPath to the erroneous value.
+ */
+struct IndexSegment : public ISegment {
+  /**
+   * Zero-based index of the element in the sequence
+   *
+   * \note XPath counts from one, so we render the index plus one.
+   */
+  size_t index;
+
+  explicit IndexSegment(
+    size_t an_index
+  );
+
+  std::wstring ToWstring() const override;
+
+  std::unique_ptr<ISegment> Clone() const override;
+
+  ~IndexSegment() override = default;
+};  // struct IndexSegment
+
+/**
+ * Represent the relative XPath to the erroneous element.
+ */
+struct Path {
+  std::deque<std::unique_ptr<ISegment> > segments;
+
+  Path();
+  Path(const Path& other);
+  Path(Path&& other);
+  Path& operator=(const Path& other);
+  Path& operator=(Path&& other);
+
+  std::wstring ToWstring() const;
+};  // struct Path
+
+}  // namespace xml_path
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_XML_PATH_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xmlization.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xmlization.hpp
new file mode 100644
index 000000000..afb303290
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/include/dummy/xmlization.hpp
@@ -0,0 +1,245 @@
+#ifndef DUMMY_XMLIZATION_GUARD_
+#define DUMMY_XMLIZATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/iteration.hpp"
+#include "dummy/types.hpp"
+#include "dummy/xml_path.hpp"
+
+#pragma warning(push, 0)
+#include <deque>
+#include <memory>
+#include <string>
+#pragma warning(pop)
+
+namespace dummy {
+
+/**
+ * \defgroup xmlization De/serialize instances from and to XML.
+ * @{
+ */
+namespace xmlization {
+
+/**
+ * Specify the expected XML namespace of all the XML elements.
+ */
+extern const std::string kNamespace;
+
+// region De-serialization
+
+/**
+ * Represent a de-serialization error.
+ */
+struct DeserializationError {
+  /**
+   * Human-readable description of the error
+   */
+  std::wstring cause;
+
+  /**
+   * Path to the erroneous value
+   */
+  xml_path::Path path;
+
+  explicit DeserializationError(std::wstring a_cause);
+  DeserializationError(std::wstring a_cause, xml_path::Path a_path);
+};  // struct DeserializationError
+
+struct ReadingOptions {
+  /**
+   * No XML attributes are expected in XML elements.
+   * Usually, attributes are considered errors and reported as such. However,
+   * some implementations add their own custom attributes, and we sometimes
+   * still want to parse such XML. If `additional_attributes` is set,
+   * the unexpected XML attributes will be ignored during parsing, and not
+   * reported.
+   */
+  bool additional_attributes = false;
+
+  /**
+   * Size of the chunk to be read from the input stream and passed to
+   * the XML parser.
+   */
+  size_t buffer_size = 1024;
+};  // struct ReadingOptions
+
+/**
+ * Deserialize the instance from an XML read from the stream \p is.
+ *
+ * \param is stream of ASCII, ISO-8859-1 or UTF-8-encoded characters to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed instance, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::IClass>,
+  DeserializationError
+> From(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+/**
+ * Deserialize an instance of types::IItem from an XML
+ * read from the stream \p is.
+ *
+ * \param is stream to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed types::IItem, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::IItem>,
+  DeserializationError
+> ItemFrom(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+/**
+ * Deserialize an instance of types::ISomeItem from an XML
+ * read from the stream \p is.
+ *
+ * \param is stream to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed types::ISomeItem, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::ISomeItem>,
+  DeserializationError
+> SomeItemFrom(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+/**
+ * Deserialize an instance of types::ISpecialItem from an XML
+ * read from the stream \p is.
+ *
+ * \param is stream to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed types::ISpecialItem, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::ISpecialItem>,
+  DeserializationError
+> SpecialItemFrom(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+/**
+ * Deserialize an instance of types::IContainer from an XML
+ * read from the stream \p is.
+ *
+ * \param is stream to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed types::IContainer, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::IContainer>,
+  DeserializationError
+> ContainerFrom(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+/**
+ * Deserialize an instance of types::IWrapper from an XML
+ * read from the stream \p is.
+ *
+ * \param is stream to read XML from
+ * \param options reading options to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \return the parsed types::IWrapper, or an error if any
+ */
+common::expected<
+  std::shared_ptr<types::IWrapper>,
+  DeserializationError
+> WrapperFrom(
+  std::istream& is,
+  const ReadingOptions& options = {}
+);
+
+// endregion Deserialization
+
+// region Serialization
+
+/**
+ * Represent an error in the serialization of an instance to XML.
+ */
+class SerializationException : public std::exception {
+ public:
+  SerializationException(
+    std::wstring cause
+  );
+
+  SerializationException(
+    std::wstring cause,
+    iteration::Path path
+  );
+
+  const char* what() const noexcept override;
+
+  const std::wstring& cause() const noexcept;
+  const iteration::Path& path() const noexcept;
+
+  ~SerializationException() noexcept override = default;
+
+ private:
+  const std::wstring cause_;
+  const iteration::Path path_;
+  const std::string msg_;
+};  // class SerializationException
+
+/**
+ * \brief Customize how instances should be serialized to XML.
+ *
+ * We selected the defaults so that they can be used when you serialize to
+ * a file.
+ */
+struct WritingOptions {
+  /**
+   * If set, the XML declaration is written at the beginning.
+   */
+  bool write_declaration = true;
+
+  /**
+   * If set, the root XML element is written with the XML namespace
+   * set as the XML attribute `xmlns`.
+   */
+  bool write_namespace = true;
+};  // struct WritingOptions
+
+/**
+ * \brief Serialize \p that instance to XML.
+ *
+ * \param that instance to be serialized
+ * \param options  to be tweaked for special cases. The defaults should
+ * work in most cases.
+ * \param os The UTF8-encoded output stream where XML will be written
+ * \throw \ref SerializationException if \p that instance could not be serialized
+ */
+void Serialize(
+  const types::IClass& that,
+  const WritingOptions& options,
+  std::ostream& os
+);
+
+// endregion Serialization
+
+}  // namespace xmlization
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_XMLIZATION_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/common.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/common.cpp
new file mode 100644
index 000000000..3b1bb5237
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/common.cpp
@@ -0,0 +1,14232 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+
+#pragma warning(push, 0)
+#include <algorithm>
+#pragma warning(pop)
+
+// NOTE (mristin):
+// We use MultiByteToWideChar and WideCharToMulitByte from <windows.h> on Windows
+// as std::codecvt is not robust enough on Windows, and produces invalid UTF-16
+// sequences as std::wstring. See:
+// https://stackoverflow.com/questions/2573834/c-convert-string-or-char-to-wstring-or-wchar-t,
+// especially the comment:
+// https://stackoverflow.com/questions/2573834/c-convert-string-or-char-to-wstring-or-wchar-t#comment110447503_18597384
+#ifdef _WIN32
+#pragma warning(push, 0)
+#include <windows.h>
+#include <limits>
+#include <cstring>
+#pragma warning(pop)
+#else
+// NOTE (mristin):
+// We use codecvt although it has been deprecated. There has been not
+// suitable replacement proposed yet, so we simply stick to it
+// until there is. See:
+// https://stackoverflow.com/questions/42946335/deprecated-header-codecvt-replacement
+
+#pragma warning(push, 0)
+#include <codecvt>
+#include <locale>
+#pragma warning(pop)
+#endif
+
+namespace dummy {
+namespace common {
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61,
+  const std::string& part62
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+  size += part62.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+  result.append(part62);
+
+  return result;
+}
+
+std::string Concat(
+  const std::string& part0,
+  const std::string& part1,
+  const std::string& part2,
+  const std::string& part3,
+  const std::string& part4,
+  const std::string& part5,
+  const std::string& part6,
+  const std::string& part7,
+  const std::string& part8,
+  const std::string& part9,
+  const std::string& part10,
+  const std::string& part11,
+  const std::string& part12,
+  const std::string& part13,
+  const std::string& part14,
+  const std::string& part15,
+  const std::string& part16,
+  const std::string& part17,
+  const std::string& part18,
+  const std::string& part19,
+  const std::string& part20,
+  const std::string& part21,
+  const std::string& part22,
+  const std::string& part23,
+  const std::string& part24,
+  const std::string& part25,
+  const std::string& part26,
+  const std::string& part27,
+  const std::string& part28,
+  const std::string& part29,
+  const std::string& part30,
+  const std::string& part31,
+  const std::string& part32,
+  const std::string& part33,
+  const std::string& part34,
+  const std::string& part35,
+  const std::string& part36,
+  const std::string& part37,
+  const std::string& part38,
+  const std::string& part39,
+  const std::string& part40,
+  const std::string& part41,
+  const std::string& part42,
+  const std::string& part43,
+  const std::string& part44,
+  const std::string& part45,
+  const std::string& part46,
+  const std::string& part47,
+  const std::string& part48,
+  const std::string& part49,
+  const std::string& part50,
+  const std::string& part51,
+  const std::string& part52,
+  const std::string& part53,
+  const std::string& part54,
+  const std::string& part55,
+  const std::string& part56,
+  const std::string& part57,
+  const std::string& part58,
+  const std::string& part59,
+  const std::string& part60,
+  const std::string& part61,
+  const std::string& part62,
+  const std::string& part63
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+  size += part62.size();
+  size += part63.size();
+
+  std::string result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+  result.append(part62);
+  result.append(part63);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61,
+  const std::wstring& part62
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+  size += part62.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+  result.append(part62);
+
+  return result;
+}
+
+std::wstring Concat(
+  const std::wstring& part0,
+  const std::wstring& part1,
+  const std::wstring& part2,
+  const std::wstring& part3,
+  const std::wstring& part4,
+  const std::wstring& part5,
+  const std::wstring& part6,
+  const std::wstring& part7,
+  const std::wstring& part8,
+  const std::wstring& part9,
+  const std::wstring& part10,
+  const std::wstring& part11,
+  const std::wstring& part12,
+  const std::wstring& part13,
+  const std::wstring& part14,
+  const std::wstring& part15,
+  const std::wstring& part16,
+  const std::wstring& part17,
+  const std::wstring& part18,
+  const std::wstring& part19,
+  const std::wstring& part20,
+  const std::wstring& part21,
+  const std::wstring& part22,
+  const std::wstring& part23,
+  const std::wstring& part24,
+  const std::wstring& part25,
+  const std::wstring& part26,
+  const std::wstring& part27,
+  const std::wstring& part28,
+  const std::wstring& part29,
+  const std::wstring& part30,
+  const std::wstring& part31,
+  const std::wstring& part32,
+  const std::wstring& part33,
+  const std::wstring& part34,
+  const std::wstring& part35,
+  const std::wstring& part36,
+  const std::wstring& part37,
+  const std::wstring& part38,
+  const std::wstring& part39,
+  const std::wstring& part40,
+  const std::wstring& part41,
+  const std::wstring& part42,
+  const std::wstring& part43,
+  const std::wstring& part44,
+  const std::wstring& part45,
+  const std::wstring& part46,
+  const std::wstring& part47,
+  const std::wstring& part48,
+  const std::wstring& part49,
+  const std::wstring& part50,
+  const std::wstring& part51,
+  const std::wstring& part52,
+  const std::wstring& part53,
+  const std::wstring& part54,
+  const std::wstring& part55,
+  const std::wstring& part56,
+  const std::wstring& part57,
+  const std::wstring& part58,
+  const std::wstring& part59,
+  const std::wstring& part60,
+  const std::wstring& part61,
+  const std::wstring& part62,
+  const std::wstring& part63
+) {
+  size_t size = 0;
+  size += part0.size();
+  size += part1.size();
+  size += part2.size();
+  size += part3.size();
+  size += part4.size();
+  size += part5.size();
+  size += part6.size();
+  size += part7.size();
+  size += part8.size();
+  size += part9.size();
+  size += part10.size();
+  size += part11.size();
+  size += part12.size();
+  size += part13.size();
+  size += part14.size();
+  size += part15.size();
+  size += part16.size();
+  size += part17.size();
+  size += part18.size();
+  size += part19.size();
+  size += part20.size();
+  size += part21.size();
+  size += part22.size();
+  size += part23.size();
+  size += part24.size();
+  size += part25.size();
+  size += part26.size();
+  size += part27.size();
+  size += part28.size();
+  size += part29.size();
+  size += part30.size();
+  size += part31.size();
+  size += part32.size();
+  size += part33.size();
+  size += part34.size();
+  size += part35.size();
+  size += part36.size();
+  size += part37.size();
+  size += part38.size();
+  size += part39.size();
+  size += part40.size();
+  size += part41.size();
+  size += part42.size();
+  size += part43.size();
+  size += part44.size();
+  size += part45.size();
+  size += part46.size();
+  size += part47.size();
+  size += part48.size();
+  size += part49.size();
+  size += part50.size();
+  size += part51.size();
+  size += part52.size();
+  size += part53.size();
+  size += part54.size();
+  size += part55.size();
+  size += part56.size();
+  size += part57.size();
+  size += part58.size();
+  size += part59.size();
+  size += part60.size();
+  size += part61.size();
+  size += part62.size();
+  size += part63.size();
+
+  std::wstring result;
+  result.reserve(size);
+
+  result.append(part0);
+  result.append(part1);
+  result.append(part2);
+  result.append(part3);
+  result.append(part4);
+  result.append(part5);
+  result.append(part6);
+  result.append(part7);
+  result.append(part8);
+  result.append(part9);
+  result.append(part10);
+  result.append(part11);
+  result.append(part12);
+  result.append(part13);
+  result.append(part14);
+  result.append(part15);
+  result.append(part16);
+  result.append(part17);
+  result.append(part18);
+  result.append(part19);
+  result.append(part20);
+  result.append(part21);
+  result.append(part22);
+  result.append(part23);
+  result.append(part24);
+  result.append(part25);
+  result.append(part26);
+  result.append(part27);
+  result.append(part28);
+  result.append(part29);
+  result.append(part30);
+  result.append(part31);
+  result.append(part32);
+  result.append(part33);
+  result.append(part34);
+  result.append(part35);
+  result.append(part36);
+  result.append(part37);
+  result.append(part38);
+  result.append(part39);
+  result.append(part40);
+  result.append(part41);
+  result.append(part42);
+  result.append(part43);
+  result.append(part44);
+  result.append(part45);
+  result.append(part46);
+  result.append(part47);
+  result.append(part48);
+  result.append(part49);
+  result.append(part50);
+  result.append(part51);
+  result.append(part52);
+  result.append(part53);
+  result.append(part54);
+  result.append(part55);
+  result.append(part56);
+  result.append(part57);
+  result.append(part58);
+  result.append(part59);
+  result.append(part60);
+  result.append(part61);
+  result.append(part62);
+  result.append(part63);
+
+  return result;
+}
+
+std::string WstringToUtf8(const std::wstring& text) {
+  #ifdef _WIN32
+  // Inspired by:
+  // https://stackoverflow.com/a/69410299/1600678
+
+  if (text.empty()) {
+    return "";
+  }
+
+  // NOTE (mristin):
+  // We put `max` into parentheses to avoid conflicts with
+  // <windows.h> `max` macro, see:
+  // https://stackoverflow.com/questions/11544073/how-do-i-deal-with-the-max-macro-in-windows-h-colliding-with-max-in-std
+
+  const size_t text_size = text.size();
+  if (
+    text_size
+    > static_cast<size_t>(
+      (std::numeric_limits<int>::max)()
+    )
+  ) {
+    throw std::out_of_range(
+      common::Concat(
+        "The size of the text to be converted to UTF-8, ",
+        std::to_string(text_size),
+        ", exceeds the maximum int value ",
+        std::to_string((std::numeric_limits<int>::max)())
+      )
+    );
+  }
+  const int text_size_int = static_cast<int>(text_size);
+
+  const auto size_needed = WideCharToMultiByte(
+    CP_UTF8,
+    0,
+    &(text[0]),
+    text_size_int,
+    nullptr,
+    0,
+    nullptr,
+    nullptr
+  );
+
+  if (size_needed <= 0) {
+    throw std::runtime_error(
+      "WideCharToMultiByte() failed: " + std::to_string(size_needed)
+    );
+  }
+
+  std::string result(size_needed, 0);
+
+  WideCharToMultiByte(
+    CP_UTF8,
+    0,
+    &(text[0]),
+    text_size_int,
+    &(result[0]),
+    size_needed,
+    nullptr,
+    nullptr
+  );
+
+  return result;
+  #else
+  // NOTE (mristin):
+  // We use codecvt although it has been deprecated. There has been not
+  // suitable replacement proposed yet, so we simply stick to it
+  // until there is. See:
+  // https://stackoverflow.com/questions/42946335/deprecated-header-codecvt-replacement
+
+  std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
+  return conv.to_bytes(text.data());
+  #endif
+}
+
+std::wstring Utf8ToWstring(
+  const char* utf8_text,
+  size_t utf8_text_size
+) {
+  if (utf8_text_size == 0) {
+    return std::wstring();
+  }
+
+  #ifdef _WIN32
+  // NOTE (mristin):
+  // We have to use MultiByteToWideChar from <windows.h> on Windows
+  // as std::codecvt is not robust enough on Windows and produces invalid UTF-16
+  // sequences as std::wstring. See:
+  // https://stackoverflow.com/questions/2573834/c-convert-string-or-char-to-wstring-or-wchar-t,
+  // especially the comment:
+  // https://stackoverflow.com/questions/2573834/c-convert-string-or-char-to-wstring-or-wchar-t#comment110447503_18597384
+
+  // Inspired by:
+  // https://stackoverflow.com/a/69410299/1600678
+
+  if (utf8_text_size == std::string::npos) {
+    utf8_text_size = strlen(utf8_text);
+  }
+
+  // NOTE (mristin):
+  // We put `max` into parentheses to avoid conflicts with
+  // <windows.h> `max` macro, see:
+  // https://stackoverflow.com/questions/11544073/how-do-i-deal-with-the-max-macro-in-windows-h-colliding-with-max-in-std
+
+  if (
+    utf8_text_size
+    > static_cast<size_t>(
+      (std::numeric_limits<int>::max)()
+    )
+  ) {
+    throw std::out_of_range(
+      common::Concat(
+        "The size of the UTF-8 text to be converted to wide string, ",
+        std::to_string(utf8_text_size),
+        ", exceeds the maximum int value ",
+        std::to_string((std::numeric_limits<int>::max)())
+      )
+    );
+  }
+  const int utf8_text_size_int = static_cast<int>(utf8_text_size);
+
+  const auto size_needed = MultiByteToWideChar(
+    CP_UTF8,
+    0,
+    utf8_text,
+    utf8_text_size_int,
+    nullptr,
+    0
+  );
+  if (size_needed <= 0) {
+    throw std::runtime_error(
+      "MultiByteToWideChar() failed: " + std::to_string(size_needed)
+    );
+  }
+
+  std::wstring result(size_needed, 0);
+
+  MultiByteToWideChar(
+    CP_UTF8,
+    0,
+    utf8_text,
+    utf8_text_size_int,
+    &(result[0]),
+    size_needed
+  );
+
+  return result;
+
+  #else
+  // NOTE (mristin):
+  // We use codecvt although it has been deprecated. There has been not
+  // suitable replacement proposed yet, so we simply stick to it
+  // until there is. See:
+  // https://stackoverflow.com/questions/42946335/deprecated-header-codecvt-replacement
+
+  std::wstring_convert<std::codecvt_utf8<wchar_t>,wchar_t> conv;
+  return conv.from_bytes(utf8_text);
+  #endif
+}
+
+std::wstring Utf8ToWstring(const std::string& utf8_text) {
+  return Utf8ToWstring(&(utf8_text[0]), utf8_text.size());
+}
+
+namespace {
+
+// NOTE (mristin):
+// The type wchar_t is a UTF-16 code unit on Windows, where a character beyond
+// the Basic Multilingual Plane takes two of them (a surrogate pair). On the other
+// platforms, wchar_t is a UTF-32 code unit, so that each character takes exactly
+// one wchar_t.
+#if WCHAR_MAX <= 0xFFFF
+/**
+ * Check whether a surrogate pair starts at \p offset in \p text.
+ */
+bool IsSurrogatePairAt(const std::wstring& text, size_t offset) {
+  return (
+    offset + 1 < text.size()
+    && text[offset] >= 0xD800
+    && text[offset] <= 0xDBFF
+    && text[offset + 1] >= 0xDC00
+    && text[offset + 1] <= 0xDFFF
+  );
+}
+
+/**
+ * Count the characters of \p text between \p start_offset and
+ * \p end_offset, both in wchar_t's.
+ */
+size_t CountCharacters(
+  const std::wstring& text,
+  size_t start_offset,
+  size_t end_offset
+) {
+  size_t count = 0;
+  size_t offset = start_offset;
+  while (offset < end_offset) {
+    offset += IsSurrogatePairAt(text, offset) ? 2 : 1;
+    ++count;
+  }
+
+  return count;
+}
+
+/**
+ * Compute the offset in wchar_t's of the character at \p position
+ * in \p text.
+ */
+size_t OffsetOf(const std::wstring& text, size_t position) {
+  size_t offset = 0;
+  for (size_t i = 0; i < position; ++i) {
+    offset += IsSurrogatePairAt(text, offset) ? 2 : 1;
+  }
+
+  return offset;
+}
+#else
+/**
+ * Count the characters of a text between \p start_offset and
+ * \p end_offset, both in wchar_t's.
+ */
+size_t CountCharacters(
+  const std::wstring&,
+  size_t start_offset,
+  size_t end_offset
+) {
+  return end_offset - start_offset;
+}
+
+/**
+ * Compute the offset in wchar_t's of the character at \p position
+ * in a text.
+ */
+size_t OffsetOf(const std::wstring&, size_t position) {
+  return position;
+}
+#endif
+
+/**
+ * Resolve \p position in a string of \p length as Python does in slicing.
+ *
+ * A negative position counts from the end, and the positions out of range are
+ * clamped to the string.
+ *
+ * \param position to be resolved
+ * \param length of the string
+ * \return the resolved position within `[0, length]`
+ */
+size_t ResolvePosition(int64_t position, size_t length) {
+  const int64_t signed_length = static_cast<int64_t>(length);
+
+  if (position < 0) {
+    const int64_t resolved = position + signed_length;
+    return resolved < 0 ? 0 : static_cast<size_t>(resolved);
+  }
+
+  return position > signed_length ? length : static_cast<size_t>(position);
+}
+
+}  // namespace
+
+size_t LenStr(const std::wstring& text) {
+  return CountCharacters(text, 0, text.size());
+}
+
+std::wstring SliceStr(
+  const std::wstring& text,
+  int64_t start,
+  int64_t end
+) {
+  const size_t length = LenStr(text);
+  const size_t the_start = ResolvePosition(start, length);
+  const size_t the_end = ResolvePosition(end, length);
+
+  if (the_start >= the_end) {
+    return L"";
+  }
+
+  const size_t start_offset = OffsetOf(text, the_start);
+  const size_t end_offset = OffsetOf(text, the_end);
+  return text.substr(start_offset, end_offset - start_offset);
+}
+
+std::wstring SliceStr(
+  const std::wstring& text,
+  int64_t start
+) {
+  return text.substr(
+    OffsetOf(text, ResolvePosition(start, LenStr(text)))
+  );
+}
+
+int64_t FindStr(
+  const std::wstring& text,
+  const std::wstring& sub
+) {
+  return FindStr(text, sub, 0);
+}
+
+int64_t FindStr(
+  const std::wstring& text,
+  const std::wstring& sub,
+  int64_t start
+) {
+  const int64_t length = static_cast<int64_t>(LenStr(text));
+
+  int64_t the_start = start;
+  if (the_start < 0) {
+    the_start += length;
+    if (the_start < 0) {
+      the_start = 0;
+    }
+  }
+
+  if (the_start > length) {
+    return -1;
+  }
+
+  const size_t start_offset = OffsetOf(text, static_cast<size_t>(the_start));
+  const size_t offset = text.find(sub, start_offset);
+  if (offset == std::wstring::npos) {
+    return -1;
+  }
+
+  return the_start + static_cast<int64_t>(
+    CountCharacters(text, start_offset, offset)
+  );
+}
+
+}  // namespace common
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/constants.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/constants.cpp
new file mode 100644
index 000000000..14781805a
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/constants.cpp
@@ -0,0 +1,25 @@
+#include "dummy/constants.hpp"
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+namespace dummy {
+namespace constants {
+
+std::size_t HashBytes::operator()(
+  const std::vector<std::uint8_t>& bytes
+) const {
+  std::size_t result = 0;
+  const std::size_t prime = 31;
+  const std::size_t size = bytes.size();
+  for (std::size_t i = 0; i < size; ++i) {
+    result = bytes[i] + (result * prime);
+  }
+  return result;
+}
+
+}  // namespace constants
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/iteration.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/iteration.cpp
new file mode 100644
index 000000000..99cefa752
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/iteration.cpp
@@ -0,0 +1,951 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/iteration.hpp"
+
+namespace dummy {
+namespace iteration {
+
+// region Pathing
+
+/**
+ * Translate the enumeration literal \p property to text.
+ *
+ * \param property to be converted into text
+ * \return text representation of \p property
+ * \throw std::invalid_argument if \p property invalid
+ */
+std::wstring PropertyToWstring(
+  Property property
+) {
+  switch (property) {
+    case Property::kContainer:
+      return L"container";
+    case Property::kItems:
+      return L"items";
+    case Property::kLevel:
+      return L"level";
+    case Property::kName:
+      return L"name";
+    case Property::kNickname:
+      return L"nickname";
+    case Property::kSomeItems:
+      return L"some_items";
+    case Property::kSpecialItems:
+      return L"special_items";
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected property literal: ",
+          std::to_string(
+            static_cast<std::uint32_t>(property)
+          )
+        )
+      );
+  }
+}  // function to_wstring
+
+// region struct PropertySegment
+
+PropertySegment::PropertySegment(Property a_property) {
+  property = a_property;
+}
+
+std::wstring PropertySegment::ToWstring() const {
+  return common::Concat(
+    L".",
+    PropertyToWstring(property)
+  );
+}
+
+std::unique_ptr<ISegment> PropertySegment::Clone() const {
+  return common::make_unique<PropertySegment>(*this);
+}
+
+// endregion struct PropertySegment
+
+// region struct IndexSegment
+
+IndexSegment::IndexSegment(size_t an_index) {
+  index = an_index;
+}
+
+std::wstring IndexSegment::ToWstring() const {
+  return common::Concat(
+    L"[",
+    std::to_wstring(index),
+    L"]"
+  );
+}
+
+std::unique_ptr<ISegment> IndexSegment::Clone() const {
+  return common::make_unique<IndexSegment>(*this);
+}
+
+// endregion struct IndexSegment
+
+// region struct KeySegment
+
+KeySegment::KeySegment(std::wstring a_key) :
+  key(std::move(a_key)) {
+  // Intentionally empty.
+}
+
+std::wstring KeySegment::ToWstring() const {
+  // NOTE (mristin):
+  // We escape the key the same way a JSON string is escaped so that
+  // the resulting path reads as a valid C++ expression on
+  // a ``nlohmann::json`` value, *e.g.*, ``.some_property["some key"]``.
+
+  std::wstring escaped;
+  escaped.reserve(key.size());
+
+  for (const wchar_t character : key) {
+    switch (character) {
+      case L'\\':
+        escaped.append(L"\\\\");
+        break;
+      case L'"':
+        escaped.append(L"\\\"");
+        break;
+      case L'\b':
+        escaped.append(L"\\b");
+        break;
+      case L'\f':
+        escaped.append(L"\\f");
+        break;
+      case L'\n':
+        escaped.append(L"\\n");
+        break;
+      case L'\r':
+        escaped.append(L"\\r");
+        break;
+      case L'\t':
+        escaped.append(L"\\t");
+        break;
+      default:
+        escaped.push_back(character);
+        break;
+    }
+  }
+
+  return common::Concat(
+    L"[\"",
+    escaped,
+    L"\"]"
+  );
+}
+
+std::unique_ptr<ISegment> KeySegment::Clone() const {
+  return common::make_unique<KeySegment>(*this);
+}
+
+// endregion struct KeySegment
+
+// region struct Path
+
+Path::Path() {
+  // Intentionally empty.
+}
+
+Path::Path(const Path& other) {
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+}
+
+Path::Path(Path&& other) {
+  segments = std::move(other.segments);
+}
+
+Path& Path::operator=(const Path& other) {
+  segments.clear();
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+  return *this;
+}
+
+Path& Path::operator=(Path&& other) {
+  if (this != &other) {
+    segments = std::move(other.segments);
+  }
+  return *this;
+}
+
+std::wstring Path::ToWstring() const {
+  std::vector<std::wstring> parts;
+  parts.reserve(segments.size());
+
+  for (const std::unique_ptr<ISegment>& segment : segments ) {
+    parts.emplace_back(segment->ToWstring());
+  }
+
+  size_t size = 0;
+  for (const std::wstring& part : parts) {
+    size += part.size();
+  }
+
+  std::wstring result;
+  result.reserve(size);
+  for (const std::wstring& part : parts) {
+    result.append(part);
+  }
+
+  return result;
+}
+
+// endregion struct Path
+
+// endregion Pathing
+
+namespace {
+
+// region Iteration over the instances
+
+/**
+ * Iterate over no instances at all.
+ */
+class EmptyIterator : public impl::IIterator {
+ public:
+  void Start() override {
+    // Intentionally empty.
+  }
+
+  void Next() override {
+    throw std::logic_error(
+      "You want to move an EmptyIterator, but it is always done."
+    );
+  }
+
+  bool Done() const override {
+    return true;
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    throw std::logic_error(
+      "You want to get an instance from an EmptyIterator, but it is always done."
+    );
+  }
+
+  void AppendToPath(Path&) const override {
+    throw std::logic_error(
+      "You want to append the path of an EmptyIterator, but it is always done."
+    );
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<EmptyIterator>(*this);
+  }
+};  // class EmptyIterator
+
+std::unique_ptr<impl::IIterator> Empty() {
+  return common::make_unique<EmptyIterator>();
+}
+
+/**
+ * \brief Iterate over the instances of the children, one child after another.
+ *
+ * A child is started only once the previous child is done.
+ */
+class ChainIterator : public impl::IIterator {
+ public:
+  explicit ChainIterator(
+    std::vector<std::unique_ptr<impl::IIterator> > children
+  ) :
+    children_(std::move(children)),
+    active_(0) {
+    // Intentionally empty.
+  }
+
+  ChainIterator(const ChainIterator& other) :
+    active_(other.active_) {
+    children_.reserve(other.children_.size());
+    for (const std::unique_ptr<impl::IIterator>& child : other.children_) {
+      children_.emplace_back(child->Clone());
+    }
+  }
+
+  void Start() override {
+    active_ = 0;
+    if (!children_.empty()) {
+      children_[0]->Start();
+    }
+    SkipDoneChildren();
+  }
+
+  void Next() override {
+    children_[active_]->Next();
+    SkipDoneChildren();
+  }
+
+  bool Done() const override {
+    return active_ >= children_.size();
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    return children_[active_]->Get();
+  }
+
+  void AppendToPath(Path& path) const override {
+    children_[active_]->AppendToPath(path);
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<ChainIterator>(*this);
+  }
+
+ private:
+  std::vector<std::unique_ptr<impl::IIterator> > children_;
+
+  /**
+   * Index of the child we currently iterate over
+   */
+  std::size_t active_;
+
+  /**
+   * Move on to the next children, and start them, until one is not done.
+   */
+  void SkipDoneChildren() {
+    while (active_ < children_.size() && children_[active_]->Done()) {
+      ++active_;
+      if (active_ < children_.size()) {
+        children_[active_]->Start();
+      }
+    }
+  }
+};  // class ChainIterator
+
+void CollectChildren(
+  std::vector<std::unique_ptr<impl::IIterator> >&
+) {
+  // Intentionally empty, as there are no more children to collect.
+}
+
+template<typename... Rest>
+void CollectChildren(
+  std::vector<std::unique_ptr<impl::IIterator> >& children,
+  std::unique_ptr<impl::IIterator> first,
+  Rest... rest
+) {
+  children.emplace_back(std::move(first));
+  CollectChildren(children, std::move(rest)...);
+}
+
+// NOTE (mristin):
+// We can not use an initializer list here, as we can not move the unique pointers
+// out of it.
+template<typename... Children>
+std::unique_ptr<impl::IIterator> Chain(
+  Children... children
+) {
+  std::vector<std::unique_ptr<impl::IIterator> > collected;
+  collected.reserve(sizeof...(Children));
+  CollectChildren(collected, std::move(children)...);
+
+  return common::make_unique<ChainIterator>(std::move(collected));
+}
+
+/**
+ * Iterate over the instances of the \p child, which lives in a property.
+ */
+class InPropertyIterator : public impl::IIterator {
+ public:
+  InPropertyIterator(
+    Property property,
+    std::unique_ptr<impl::IIterator> child
+  ) :
+    property_(property),
+    child_(std::move(child)) {
+    // Intentionally empty.
+  }
+
+  InPropertyIterator(const InPropertyIterator& other) :
+    property_(other.property_),
+    child_(other.child_->Clone()) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    child_->Start();
+  }
+
+  void Next() override {
+    child_->Next();
+  }
+
+  bool Done() const override {
+    return child_->Done();
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    return child_->Get();
+  }
+
+  void AppendToPath(Path& path) const override {
+    path.segments.emplace_back(
+      common::make_unique<PropertySegment>(property_)
+    );
+    child_->AppendToPath(path);
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<InPropertyIterator>(*this);
+  }
+
+ private:
+  Property property_;
+  std::unique_ptr<impl::IIterator> child_;
+};  // class InPropertyIterator
+
+std::unique_ptr<impl::IIterator> InProperty(
+  Property property,
+  std::unique_ptr<impl::IIterator> child
+) {
+  return common::make_unique<InPropertyIterator>(property, std::move(child));
+}
+
+/**
+ * \brief Iterate over the instances of every item of a list, one item after another.
+ *
+ * The iterator over an item is built only once the iteration reaches the item.
+ */
+template<typename T>
+class EachIterator : public impl::IIterator {
+ public:
+  /**
+   * Build the iterator over the instances of an item
+   */
+  typedef std::unique_ptr<impl::IIterator> (*OverItem)(
+    const T& item,
+    bool recursive
+  );
+
+  EachIterator(
+    const std::vector<T>* items,
+    OverItem over_item,
+    bool recursive
+  ) :
+    items_(items),
+    over_item_(over_item),
+    recursive_(recursive),
+    index_(0) {
+    // Intentionally empty.
+  }
+
+  EachIterator(const EachIterator<T>& other) :
+    items_(other.items_),
+    over_item_(other.over_item_),
+    recursive_(other.recursive_),
+    index_(other.index_),
+    item_(other.item_ == nullptr ? nullptr : other.item_->Clone()) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    index_ = 0;
+    item_ = nullptr;
+    SkipDoneItems();
+  }
+
+  void Next() override {
+    item_->Next();
+    SkipDoneItems();
+  }
+
+  bool Done() const override {
+    return index_ >= items_->size();
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    return item_->Get();
+  }
+
+  void AppendToPath(Path& path) const override {
+    path.segments.emplace_back(
+      common::make_unique<IndexSegment>(index_)
+    );
+    item_->AppendToPath(path);
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<EachIterator<T> >(*this);
+  }
+
+ private:
+  const std::vector<T>* items_;
+  OverItem over_item_;
+  bool recursive_;
+
+  /**
+   * Index of the item we currently iterate over
+   */
+  std::size_t index_;
+
+  /**
+   * Iterator over the current item, built once we reached the item
+   */
+  std::unique_ptr<impl::IIterator> item_;
+
+  /**
+   * Move on to the next items, and build their iterators, until one is not done.
+   */
+  void SkipDoneItems() {
+    while (index_ < items_->size()) {
+      if (item_ == nullptr) {
+        item_ = over_item_((*items_)[index_], recursive_);
+        item_->Start();
+      }
+
+      if (!item_->Done()) {
+        return;
+      }
+
+      item_ = nullptr;
+      ++index_;
+    }
+  }
+};  // class EachIterator
+
+template<typename T>
+std::unique_ptr<impl::IIterator> Each(
+  const std::vector<T>& items,
+  std::unique_ptr<impl::IIterator> (*over_item)(const T& item, bool recursive),
+  bool recursive
+) {
+  return common::make_unique<EachIterator<T> >(&items, over_item, recursive);
+}
+
+/**
+ * \brief Iterate over a single instance.
+ *
+ * We keep a copy of the shared pointer, upcast to types::IClass, so that
+ * \ref Get can return a reference to it.
+ */
+class OneIterator : public impl::IIterator {
+ public:
+  explicit OneIterator(
+    std::shared_ptr<types::IClass> instance
+  ) :
+    instance_(std::move(instance)),
+    done_(true) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    done_ = false;
+  }
+
+  void Next() override {
+    done_ = true;
+  }
+
+  bool Done() const override {
+    return done_;
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    return instance_;
+  }
+
+  void AppendToPath(Path&) const override {
+    // Intentionally empty, as the instance itself is the end of the path.
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<OneIterator>(*this);
+  }
+
+ private:
+  std::shared_ptr<types::IClass> instance_;
+  bool done_;
+};  // class OneIterator
+
+std::unique_ptr<impl::IIterator> One(
+  std::shared_ptr<types::IClass> instance
+) {
+  return common::make_unique<OneIterator>(std::move(instance));
+}
+
+/**
+ * \brief Iterate over the instances referenced from an instance, dispatched on
+ * its runtime type.
+ *
+ * Defined below, once all the classes have been covered.
+ */
+std::unique_ptr<impl::IIterator> DispatchOnModelType(
+  const types::IClass& instance,
+  bool recursive
+);
+
+/**
+ * \brief Iterate recursively over the instances referenced from an instance.
+ *
+ * We dispatch on the runtime type of the instance only in \ref Start so that
+ * we descend into the instance only once the iteration reaches it.
+ */
+class DispatchingIterator : public impl::IIterator {
+ public:
+  explicit DispatchingIterator(
+    const types::IClass* instance
+  ) :
+    instance_(instance) {
+    // Intentionally empty.
+  }
+
+  DispatchingIterator(const DispatchingIterator& other) :
+    instance_(other.instance_),
+    child_(other.child_ == nullptr ? nullptr : other.child_->Clone()) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    child_ = DispatchOnModelType(*instance_, true);
+    child_->Start();
+  }
+
+  void Next() override {
+    child_->Next();
+  }
+
+  bool Done() const override {
+    return child_->Done();
+  }
+
+  const std::shared_ptr<types::IClass>& Get() const override {
+    return child_->Get();
+  }
+
+  void AppendToPath(Path& path) const override {
+    child_->AppendToPath(path);
+  }
+
+  std::unique_ptr<impl::IIterator> Clone() const override {
+    return common::make_unique<DispatchingIterator>(*this);
+  }
+
+ private:
+  const types::IClass* instance_;
+  std::unique_ptr<impl::IIterator> child_;
+};  // class DispatchingIterator
+
+/**
+ * Iterate over the instances referenced from the \p instance, if \p recursive.
+ */
+std::unique_ptr<impl::IIterator> Over(
+  const types::IClass& instance,
+  bool recursive
+) {
+  if (!recursive) {
+    // NOTE (mristin):
+    // In the non-recursive mode, we iterate only over the instances referenced
+    // directly, but not over the instances which they reference in turn.
+    return Empty();
+  }
+
+  return common::make_unique<DispatchingIterator>(&instance);
+}
+
+/**
+ * Iterate over the \p instance, and then over the instances that it references.
+ */
+template<typename T>
+std::unique_ptr<impl::IIterator> OneThenOver(
+  const std::shared_ptr<T>& instance,
+  bool recursive
+) {
+  return Chain(One(instance), Over(*instance, recursive));
+}
+
+using listOf_Item = std::vector<
+  std::shared_ptr<types::IItem>
+>;
+
+using listOf_SomeItem = std::vector<
+  std::shared_ptr<types::ISomeItem>
+>;
+
+using listOf_SpecialItem = std::vector<
+  std::shared_ptr<types::ISpecialItem>
+>;
+
+std::unique_ptr<impl::IIterator> Over_listOf_Item(
+  const listOf_Item& value,
+  bool recursive
+) {
+  return Each(value, &OneThenOver<types::IItem>, recursive);
+}
+
+std::unique_ptr<impl::IIterator> Over_listOf_SomeItem(
+  const listOf_SomeItem& value,
+  bool recursive
+) {
+  return Each(value, &OneThenOver<types::ISomeItem>, recursive);
+}
+
+std::unique_ptr<impl::IIterator> Over_listOf_SpecialItem(
+  const listOf_SpecialItem& value,
+  bool recursive
+) {
+  return Each(value, &OneThenOver<types::ISpecialItem>, recursive);
+}
+
+std::unique_ptr<impl::IIterator> Over_Container(
+  const types::IContainer& that,
+  bool recursive
+) {
+  return Chain(
+    InProperty(
+      Property::kItems,
+      Over_listOf_Item(that.items(), recursive)
+    ),
+    InProperty(
+      Property::kSomeItems,
+      Over_listOf_SomeItem(that.some_items(), recursive)
+    ),
+    InProperty(
+      Property::kSpecialItems,
+      that.special_items().has_value()
+        ? Over_listOf_SpecialItem((*that.special_items()), recursive)
+        : Empty()
+    )
+  );
+}
+
+std::unique_ptr<impl::IIterator> Over_Wrapper(
+  const types::IWrapper& that,
+  bool recursive
+) {
+  return InProperty(
+    Property::kContainer,
+    OneThenOver(that.container(), recursive)
+  );
+}
+
+/**
+ * \brief Iterate over the instances referenced from the \p instance,
+ * dispatched on its runtime type.
+ *
+ * If \p recursive, we iterate also over the instances which the referenced
+ * instances reference in turn.
+ */
+std::unique_ptr<impl::IIterator> DispatchOnModelType(
+  const types::IClass& instance,
+  bool recursive
+) {
+  switch (instance.model_type()) {
+    case types::ModelType::kContainer:
+      return Over_Container(
+        dynamic_cast<const types::IContainer&>(instance),
+        recursive
+      );
+    case types::ModelType::kWrapper:
+      return Over_Wrapper(
+        dynamic_cast<const types::IWrapper&>(instance),
+        recursive
+      );
+    default:
+      // NOTE (mristin):
+      // The instances of the other classes reference no other instances.
+      return Empty();
+  }
+}
+
+// endregion Iteration over the instances
+
+}  // namespace
+
+// region Iterator facade
+
+Iterator::Iterator(
+  const Iterator& other
+) :
+  implementation_(other.implementation_->Clone()),
+  index_(other.index_) {
+  // Intentionally empty.
+}
+
+Iterator::Iterator(
+  Iterator&& other
+) :
+  implementation_(std::move(other.implementation_)),
+  index_(other.index_) {
+  // Intentionally empty.
+}
+
+Iterator& Iterator::operator=(const Iterator& other) {
+  return *this = Iterator(other);
+}
+
+Iterator& Iterator::operator=(Iterator&& other) {
+  if (this != &other) {
+    implementation_ = std::move(other.implementation_);
+    index_ = other.index_;
+  }
+
+  return *this;
+}
+
+const std::shared_ptr<types::IClass>& Iterator::operator*() const {
+  if (implementation_->Done()) {
+    throw std::logic_error(
+      "You want to dereference a completed iterator."
+    );
+  }
+
+  return implementation_->Get();
+}
+
+const std::shared_ptr<types::IClass>* Iterator::operator->() {
+  if (implementation_->Done()) {
+    throw std::logic_error(
+      "You want to dereference a completed iterator."
+    );
+  }
+
+  return &(implementation_->Get());
+}
+
+// Prefix increment
+Iterator& Iterator::operator++() {
+  if (implementation_->Done()) {
+    throw std::logic_error(
+      "You want to move a completed iterator."
+    );
+  }
+
+  implementation_->Next();
+  index_ = implementation_->Done() ? -1 : index_ + 1;
+  return *this;
+}
+
+// Postfix increment
+Iterator Iterator::operator++(int) {
+  Iterator result(*this);
+  ++(*this);
+  return result;
+}
+
+bool operator==(const Iterator& a, const Iterator& b) {
+  return a.index_ == b.index_;
+}
+
+bool operator!=(const Iterator& a, const Iterator& b) {
+  return a.index_ != b.index_;
+}
+
+Path MaterializePath(const Iterator& iterator) {
+  if (iterator.implementation_->Done()) {
+    throw std::logic_error(
+      "You want to materialize path of a completed iterator."
+    );
+  }
+
+  Path path;
+  iterator.implementation_->AppendToPath(path);
+  return path;
+}
+
+void PrependToPath(const Iterator& iterator, Path* path) {
+  if (iterator.implementation_->Done()) {
+    throw std::logic_error(
+      "You want to prepend a path of a completed iterator."
+    );
+  }
+
+  Path prefix;
+  iterator.implementation_->AppendToPath(prefix);
+
+  for (
+    auto it = prefix.segments.rbegin();
+    it != prefix.segments.rend();
+    ++it
+  ) {
+    path->segments.emplace_front(std::move(*it));
+  }
+}
+
+// endregion Iterator facade
+
+// region Descents
+
+// region Descent
+
+// NOTE (mristin):
+// We have to make a copy of the pointer since we would lose otherwise
+// in range-based `for` loops,
+// see: https://stackoverflow.com/questions/29990045/temporary-lifetime-in-range-for-expression
+Descent::Descent(
+  std::shared_ptr<types::IClass> instance
+) : instance_(std::move(instance)) {
+  // Intentionally empty.
+}
+
+Iterator Descent::begin() const {
+  std::unique_ptr<impl::IIterator> it_impl(
+    DispatchOnModelType(*instance_, true)
+  );
+
+  it_impl->Start();
+
+  // NOTE(mristin):
+  // We short-circuit here for memory frugality,
+  // as we can immediately dispose it_impl.
+  if (it_impl->Done()) {
+    return end();
+  }
+
+  return Iterator(std::move(it_impl));
+}
+
+const Iterator& Descent::end() const {
+  static Iterator iterator(Empty());
+  return iterator;
+}
+
+// endregion Descent
+
+// region DescentOnce
+
+// NOTE (mristin):
+// We have to make a copy of the pointer since we would lose otherwise
+// in range-based `for` loops,
+// see: https://stackoverflow.com/questions/29990045/temporary-lifetime-in-range-for-expression
+DescentOnce::DescentOnce(
+  std::shared_ptr<types::IClass> instance
+) : instance_(std::move(instance)) {
+  // Intentionally empty.
+}
+
+Iterator DescentOnce::begin() const {
+  std::unique_ptr<impl::IIterator> it_impl(
+    DispatchOnModelType(*instance_, false)
+  );
+
+  it_impl->Start();
+
+  // NOTE(mristin):
+  // We short-circuit here for memory frugality,
+  // as we can immediately dispose it_impl.
+  if (it_impl->Done()) {
+    return end();
+  }
+
+  return Iterator(std::move(it_impl));
+}
+
+const Iterator& DescentOnce::end() const {
+  static Iterator iterator(Empty());
+  return iterator;
+}
+
+// endregion DescentOnce
+
+// endregion Descents
+
+}  // namespace iteration
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/jsonization.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/jsonization.cpp
new file mode 100644
index 000000000..6fec18c96
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/jsonization.cpp
@@ -0,0 +1,2917 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/jsonization.hpp"
+#include "dummy/stringification.hpp"
+#include "dummy/wstringification.hpp"
+
+#pragma warning(push, 0)
+#include <cmath>
+#include <set>
+#include <sstream>
+#include <unordered_map>
+#pragma warning(pop)
+
+namespace dummy {
+namespace jsonization {
+
+// region JSON path helpers
+
+/**
+ * \brief Escape \p text as the content of a JSON string.
+ *
+ * The control characters without a short escape are written as Unicode
+ * escapes, as JSON.stringify does.
+ */
+std::wstring EscapeForJsonString(
+  const std::wstring& text
+) {
+  static const wchar_t* const kHexDigits = L"0123456789abcdef";
+
+  std::wstring escaped;
+  escaped.reserve(text.size());
+  for (const wchar_t character : text) {
+    switch (character) {
+      case L'\\':
+        escaped.append(L"\\\\");
+        break;
+      case L'"':
+        escaped.append(L"\\\"");
+        break;
+      case L'\b':
+        escaped.append(L"\\b");
+        break;
+      case L'\f':
+        escaped.append(L"\\f");
+        break;
+      case L'\n':
+        escaped.append(L"\\n");
+        break;
+      case L'\r':
+        escaped.append(L"\\r");
+        break;
+      case L'\t':
+        escaped.append(L"\\t");
+        break;
+      default:
+        if (static_cast<uint32_t>(character) < 0x20) {
+          escaped.append(L"\\u00");
+          escaped.push_back(kHexDigits[(character >> 4) & 0xF]);
+          escaped.push_back(kHexDigits[character & 0xF]);
+        } else {
+          escaped.push_back(character);
+        }
+        break;
+    }
+  }
+
+  return escaped;
+}
+
+/**
+ * \brief Check whether a JSON path writes the property \p name after a dot.
+ *
+ * The other names are written in brackets as JSON strings,
+ * <em>e.g.</em>, <code>["$eq"]</code>.
+ */
+bool IsVariableName(
+  const std::wstring& name
+) {
+  if (name.empty()) {
+    return false;
+  }
+
+  for (size_t i = 0; i < name.size(); ++i) {
+    const wchar_t character = name[i];
+
+    const bool is_letter_or_underscore = (
+      (character >= L'a' && character <= L'z')
+      || (character >= L'A' && character <= L'Z')
+      || character == L'_'
+    );
+
+    const bool is_digit = character >= L'0' && character <= L'9';
+
+    if (!(is_letter_or_underscore || (i > 0 && is_digit))) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// endregion JSON path helpers
+
+// region PropertySegment
+
+PropertySegment::PropertySegment(
+  std::wstring a_name
+) :
+  name(std::move(a_name)) {
+  // Intentionally empty.
+}
+
+std::wstring PropertySegment::ToWstring() const {
+  if (IsVariableName(name)) {
+    return common::Concat(
+      L".",
+      name
+    );
+  }
+
+  return common::Concat(
+    L"[\"",
+    EscapeForJsonString(name),
+    L"\"]"
+  );
+}
+
+std::unique_ptr<ISegment> PropertySegment::Clone() const {
+  return common::make_unique<PropertySegment>(*this);
+}
+
+// endregion PropertySegment
+
+// region IndexSegment
+
+IndexSegment::IndexSegment(
+  size_t an_index
+) :
+  index(an_index) {
+  // Intentionally empty.
+}
+
+std::wstring IndexSegment::ToWstring() const {
+  return common::Concat(
+    L"[",
+    std::to_wstring(index),
+    L"]"
+  );
+}
+
+std::unique_ptr<ISegment> IndexSegment::Clone() const {
+  return common::make_unique<IndexSegment>(*this);
+}
+
+// endregion IndexSegment
+
+// region KeySegment
+
+KeySegment::KeySegment(
+  std::wstring a_key
+) :
+  key(std::move(a_key)) {
+  // Intentionally empty.
+}
+
+std::wstring KeySegment::ToWstring() const {
+  // NOTE (mristin):
+  // A key can be any string at all, so we always write it as a JSON string in
+  // brackets, as in the other SDKs.
+  return common::Concat(
+    L"[\"",
+    EscapeForJsonString(key),
+    L"\"]"
+  );
+}
+
+std::unique_ptr<ISegment> KeySegment::Clone() const {
+  return common::make_unique<KeySegment>(*this);
+}
+
+// endregion KeySegment
+
+// region struct Path
+
+Path::Path() {
+  // Intentionally empty.
+}
+
+Path::Path(const Path& other) {
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+}
+
+Path::Path(Path&& other) {
+  segments = std::move(other.segments);
+}
+
+Path& Path::operator=(const Path& other) {
+  segments.clear();
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+  return *this;
+}
+
+Path& Path::operator=(Path&& other) {
+  if (this != &other) {
+    segments = std::move(other.segments);
+  }
+  return *this;
+}
+
+std::wstring Path::ToWstring() const {
+  if (segments.empty()) {
+    return L"";
+  }
+
+  std::deque<std::wstring> parts;
+  for (const std::unique_ptr<ISegment>& segment : segments ) {
+    parts.emplace_back(segment->ToWstring());
+  }
+
+  // NOTE (mristin):
+  // The path starts with the name of the first property without a dot, as in
+  // the other SDKs, *e.g.*, ``items[0].name``.
+  const PropertySegment* first_property(
+    dynamic_cast<const PropertySegment*>(segments.front().get())
+  );
+  if (first_property != nullptr && IsVariableName(first_property->name)) {
+    parts.front() = first_property->name;
+  }
+
+  size_t out_len = 0;
+  for (const std::wstring& part : parts) {
+    out_len += part.size();
+  }
+
+  std::wstring out;
+  out.reserve(out_len);
+  for (const std::wstring& part : parts) {
+    out.append(part);
+  }
+
+  return out;
+}
+
+// endregion struct Path
+
+// region De-serialization
+
+// region class DeserializationError
+
+DeserializationError::DeserializationError(
+  std::wstring a_cause
+) :
+  cause(a_cause) {
+  // Intentionally empty.
+}
+
+DeserializationError::DeserializationError(
+  std::wstring a_cause,
+  Path a_path
+) :
+  cause(a_cause),
+  path(a_path) {
+  // Intentionally empty.
+}
+
+// endregion class DeserializationError
+
+std::pair<
+  common::optional<bool>,
+  common::optional<DeserializationError>
+> DeserializeBool(
+  const nlohmann::json& json
+) {
+  if (!json.is_boolean()) {
+    std::wstring message = common::Concat(
+      L"Expected a boolean, but got a value of type: ",
+      common::Utf8ToWstring(json.type_name())
+    );
+
+    return std::make_pair<
+      common::optional<bool>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<bool>,
+    common::optional<DeserializationError>
+  >(
+    json.get<bool>(),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<int64_t>,
+  common::optional<DeserializationError>
+> DeserializeInt64(
+  const nlohmann::json& json
+) {
+  if (!json.is_number()) {
+    std::wstring message = common::Concat(
+      L"Expected an integer number, but got a value of type: ",
+      common::Utf8ToWstring(json.type_name())
+    );
+
+    return std::make_pair<
+      common::optional<int64_t>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  static_assert(
+    std::is_same<nlohmann::json::number_integer_t, int64_t>::value,
+    "Expected nlohmann::json::number_integer_t to equal int64_t, "
+    "but it does not."
+  );
+
+  if (json.is_number_integer()) {
+    return std::make_pair<
+      common::optional<int64_t>,
+      common::optional<DeserializationError>
+    >(
+      json.get<int64_t>(),
+      common::nullopt
+    );
+  }
+
+  if (json.is_number_unsigned()) {
+    std::wstring message = common::Concat(
+      L"Expected a 64-bit integer number, "
+      L"but got an unsigned integer number which does not fit in that range: ",
+      std::to_wstring(json.get<nlohmann::json::number_unsigned_t>())
+    );
+
+    return std::make_pair<
+      common::optional<int64_t>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  // NOTE (mristin):
+  // We have to check that the number is an integer even though it can
+  // not be stored in int64_t in order to give an informative message.
+
+  const nlohmann::json::number_float_t number(
+    json.get<nlohmann::json::number_float_t>()
+  );
+
+  nlohmann::json::number_float_t integer_part;
+  const bool is_integer(
+    std::modf(number, &integer_part) == 0
+  );
+  if (is_integer) {
+    std::wstring message = common::Concat(
+      L"Expected a 64-bit integer number, "
+      L"but got an integer number which does not fit in that range: ",
+      std::to_wstring(number)
+    );
+
+    return std::make_pair<
+      common::optional<int64_t>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  } else {
+    std::wstring message = common::Concat(
+      L"Expected a 64-bit integer number, "
+      L"but got a non-integer number: ",
+      std::to_wstring(number)
+    );
+
+    return std::make_pair<
+      common::optional<int64_t>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+}
+
+std::pair<
+  common::optional<double>,
+  common::optional<DeserializationError>
+> DeserializeDouble(
+  const nlohmann::json& json
+) {
+  if (!json.is_number()) {
+    std::wstring message = common::Concat(
+      L"Expected a number, but got a value of type: ",
+      common::Utf8ToWstring(json.type_name())
+    );
+
+    return std::make_pair<
+      common::optional<double>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  static_assert(
+    std::is_same<nlohmann::json::number_float_t, double>::value,
+    "Expected nlohmann::json::number_float_t to equal double, "
+    "but it does not."
+  );
+
+  const double value(json.get<double>());
+
+  // NOTE (mristin):
+  // JSON knows neither an infinity nor a not-a-number, so a conformant parser
+  // can never give us one. The caller can still hand us a JSON value which
+  // has been constructed programmatically, so we have to check here.
+
+  if (!std::isfinite(value)) {
+    std::wstring message = common::Concat(
+      L"Expected a finite number, but got: ",
+      std::to_wstring(value)
+    );
+
+    return std::make_pair<
+      common::optional<double>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<double>,
+    common::optional<DeserializationError>
+  >(
+    value,
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<std::wstring>,
+  common::optional<DeserializationError>
+> DeserializeWstring(
+  const nlohmann::json& json
+) {
+  if (!json.is_string()) {
+    std::wstring message = common::Concat(
+      L"Expected a string, but got a value of type: ",
+      common::Utf8ToWstring(json.type_name())
+    );
+
+    return std::make_pair<
+      common::optional<std::wstring>,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<std::wstring>,
+    common::optional<DeserializationError>
+  >(
+    common::Utf8ToWstring(*(json.get_ptr<const std::string*>())),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<std::vector<std::uint8_t> >,
+  common::optional<DeserializationError>
+> DeserializeByteArray(
+  const nlohmann::json& json
+) {
+  if (!json.is_string()) {
+    std::wstring message = common::Concat(
+      L"Expected a base64-encoded byte array as a string, "
+      L"but got a value of type: ",
+      common::Utf8ToWstring(json.type_name())
+    );;
+
+    return std::make_pair<
+      common::optional<std::vector<std::uint8_t> >,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  common::expected<
+    std::vector<std::uint8_t>,
+    std::string
+  > bytes = stringification::Base64Decode(
+    *(json.get_ptr<const std::string*>())
+  );
+
+  if (!bytes.has_value()) {
+    std::wstring message = common::Concat(
+      L"Failed to base64-decode the bytes from a string: ",
+      common::Utf8ToWstring(bytes.error())
+    );
+
+    return std::make_pair<
+      common::optional<std::vector<std::uint8_t> >,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<std::vector<std::uint8_t> >,
+    common::optional<DeserializationError>
+  >(
+    std::move(*bytes),
+    common::nullopt
+  );
+}
+
+/**
+ * Get the property `modelType` from the JSON value expected as a JSON object.
+ */
+std::pair<
+  const std::string*,
+  common::optional<DeserializationError>
+> GetModelTypeFrom(
+  const nlohmann::json& json
+) {
+  if (!json.is_object()) {
+    std::wstring message = common::Concat(
+      L"Expected an object, but got: ",
+      common::Utf8ToWstring(json.type_name())
+    );
+
+    return std::make_pair<
+      const std::string*,
+      common::optional<DeserializationError>
+    >(
+      nullptr,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  if (!json.contains("modelType")) {
+    return std::make_pair<
+      const std::string*,
+      common::optional<DeserializationError>
+    >(
+      nullptr,
+      common::make_optional<DeserializationError>(
+        L"The required property modelType is missing"
+      )
+    );
+  }
+
+  const nlohmann::json& model_type_prop = json["modelType"];
+  if (!model_type_prop.is_string()) {
+    std::wstring message = common::Concat(
+      L"Expected modelType to be a string, but got: ",
+      common::Utf8ToWstring(model_type_prop.type_name())
+    );
+
+    common::optional<DeserializationError> error(
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+    error->path.segments.emplace_front(
+      common::make_unique<PropertySegment>(
+        L"modelType"
+      )
+    );
+
+    // NOTE (mristin):
+    // We have to explicitly use the constructor instead of std::make_pair
+    // as `const std::string*` can not be automatically converted to a rvalue.
+    return std::pair<
+      const std::string*,
+      common::optional<DeserializationError>
+    >(
+      nullptr,
+      error
+    );
+  }
+
+  static_assert(
+    std::is_same<nlohmann::json::string_t, std::string>::value,
+    "Expected nlohmann::json::string_t to equal std::string, but it does not."
+  );
+
+  const std::string* model_type(
+    model_type_prop.get_ptr<const std::string*>()
+  );
+
+  // NOTE (mristin):
+  // We have to explicitly use the constructor instead of std::make_pair
+  // as `const std::string*` can not be automatically converted to a rvalue.
+  return std::pair<
+    const std::string*,
+    common::optional<DeserializationError>
+  >(
+    model_type,
+    common::nullopt
+  );
+}
+
+/**
+ * \brief Give out a failed de-serialization with \p cause as its message.
+ *
+ * \tparam T type of the value which could not be de-serialized
+ * \param cause human-readable description of the failure
+ * \return no value, and the error
+ */
+template <typename T>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> NoInstanceAndDeserializationErrorWithCause(
+  std::wstring cause
+) {
+  return std::make_pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >(
+    common::nullopt,
+    common::make_optional<DeserializationError>(
+      std::move(cause)
+    )
+  );
+}
+
+/**
+ * \brief Give out a failed de-serialization with \p error.
+ *
+ * \tparam T type of the value which could not be de-serialized
+ * \param error of the de-serialization
+ * \return no value, and the error
+ */
+template <typename T>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> NoInstanceAndDeserializationError(
+  DeserializationError error
+) {
+  return std::make_pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >(
+    common::nullopt,
+    common::make_optional<DeserializationError>(
+      std::move(error)
+    )
+  );
+}
+
+/**
+ * Map JSON \c modelType strings to model types.
+ */
+const std::unordered_map<
+  std::string,
+  types::ModelType
+> kModelTypeStringToModelType = {
+  {
+    "SomeItem",
+    types::ModelType::kSomeItem
+  },
+  {
+    "SpecialItem",
+    types::ModelType::kSpecialItem
+  },
+  {
+    "Container",
+    types::ModelType::kContainer
+  },
+  {
+    "Wrapper",
+    types::ModelType::kWrapper
+  }
+};
+
+common::optional<types::ModelType> ModelTypeFromModelTypeString(
+  const std::string& model_type_str
+) {
+  auto it = kModelTypeStringToModelType.find(model_type_str);
+  if (it == kModelTypeStringToModelType.end()) {
+    return common::nullopt;
+  }
+
+  return it->second;
+}
+
+/**
+ * \brief De-serialize a list of items from \p json.
+ *
+ * \param json value expected to be an array
+ * \param deserialize_item de-serializes an item
+ * \return the list, or an error, if any
+ */
+template <typename T, typename DeserializeItemT>
+std::pair<
+  common::optional<std::vector<T> >,
+  common::optional<DeserializationError>
+> DeserializeList(
+  const nlohmann::json& json,
+  DeserializeItemT&& deserialize_item
+) {
+  if (!json.is_array()) {
+    std::wstring message = common::Concat(
+      L"Expected an array, but got: ",
+      common::Utf8ToWstring(
+        json.type_name()
+      )
+    );
+
+    return std::make_pair<
+      common::optional<std::vector<T> >,
+      common::optional<DeserializationError>
+    >(
+      common::nullopt,
+      common::make_optional<DeserializationError>(
+        message
+      )
+    );
+  }
+
+  common::optional<std::vector<T> > list(
+    common::make_optional<std::vector<T> >()
+  );
+
+  list->reserve(json.size());
+
+  size_t index = 0;
+
+  for(const nlohmann::json& item : json) {
+    common::optional<T> deserialized;
+    common::optional<DeserializationError> error;
+
+    std::tie(deserialized, error) = deserialize_item(item);
+
+    if (error.has_value()) {
+      error->path.segments.emplace_front(
+        common::make_unique<IndexSegment>(
+          index
+        )
+      );
+
+      return std::make_pair<
+        common::optional<std::vector<T> >,
+        common::optional<DeserializationError>
+      >(
+        common::nullopt,
+        std::move(error)
+      );
+    }
+
+    list->emplace_back(std::move(*deserialized));
+
+    ++index;
+  }
+
+  return std::make_pair(
+    list,
+    common::nullopt
+  );
+}
+
+/**
+ * \brief De-serialize a list of instances from \p json.
+ *
+ * \param json value expected to be an array
+ * \param additional_properties handed over to \p deserialize_item
+ * \param deserialize_item de-serializes an item
+ * \return the list, or an error, if any
+ */
+template <typename T, typename DeserializeItemT>
+std::pair<
+  common::optional<std::vector<T> >,
+  common::optional<DeserializationError>
+> DeserializeList(
+  const nlohmann::json& json,
+  bool additional_properties,
+  DeserializeItemT&& deserialize_item
+) {
+  return DeserializeList<T>(
+    json,
+    [&additional_properties, &deserialize_item](
+      const nlohmann::json& item
+    ) {
+      return deserialize_item(item, additional_properties);
+    }
+  );
+}
+
+namespace properties {
+
+enum class OfSomeItem : std::uint32_t {
+  kName,
+  kNickname,
+  kModelType
+};  // enum class OfSomeItem
+
+enum class OfSpecialItem : std::uint32_t {
+  kName,
+  kNickname,
+  kLevel,
+  kModelType
+};  // enum class OfSpecialItem
+
+enum class OfContainer : std::uint32_t {
+  kItems,
+  kSomeItems,
+  kSpecialItems
+};  // enum class OfContainer
+
+enum class OfWrapper : std::uint32_t {
+  kContainer
+};  // enum class OfWrapper
+
+const std::unordered_map<
+  std::string,
+  OfSomeItem
+> kMapOfSomeItem = {
+  {
+    "name",
+    OfSomeItem::kName
+  },
+  {
+    "nickname",
+    OfSomeItem::kNickname
+  },
+  {
+    "modelType",
+    OfSomeItem::kModelType
+  }
+};
+
+const std::unordered_map<
+  std::string,
+  OfSpecialItem
+> kMapOfSpecialItem = {
+  {
+    "name",
+    OfSpecialItem::kName
+  },
+  {
+    "nickname",
+    OfSpecialItem::kNickname
+  },
+  {
+    "level",
+    OfSpecialItem::kLevel
+  },
+  {
+    "modelType",
+    OfSpecialItem::kModelType
+  }
+};
+
+const std::unordered_map<
+  std::string,
+  OfContainer
+> kMapOfContainer = {
+  {
+    "items",
+    OfContainer::kItems
+  },
+  {
+    "someItems",
+    OfContainer::kSomeItems
+  },
+  {
+    "specialItems",
+    OfContainer::kSpecialItems
+  }
+};
+
+const std::unordered_map<
+  std::string,
+  OfWrapper
+> kMapOfWrapper = {
+  {
+    "container",
+    OfWrapper::kContainer
+  }
+};
+
+}  // namespace properties
+
+/**
+ * \brief Create the exception to be thrown on an unexpected property literal.
+ *
+ * Every ``switch`` over the properties of a class covers all the literals of
+ * its enumeration, so we can only get here if the value has been corrupted.
+ * We report that as a logic error, and not as a de-serialization error, since
+ * it does not originate in the input.
+ *
+ * \param enum_name name of the property enumeration, for the message
+ * \param property the unexpected literal
+ * \return the exception to be thrown
+ */
+template <typename EnumT>
+std::logic_error UnexpectedPropertyLiteralError(
+  const char* enum_name,
+  EnumT property
+) {
+  return std::logic_error(
+    common::Concat(
+      "Unexpected properties literal of ",
+      enum_name,
+      ": ",
+      std::to_string(
+        static_cast<std::uint32_t>(property)
+      )
+    )
+  );
+}
+
+/**
+ * \brief Parse the properties of an instance from \p json.
+ *
+ * This function factors out everything which the property loop of a class does
+ * not say about the class it belongs to: walking the keys, looking the property
+ * up, refusing or accepting an unknown one and marking the property on
+ * the error path. The class itself supplies only \p on_property, which
+ * dispatches on the property and assigns the local variables that its
+ * constructor is finally called with.
+ *
+ * NOTE (mristin):
+ * We walk the keys which are actually there, instead of asking for each
+ * property of the class whether it is there. An instance carries only a few of
+ * the many properties which a class declares, and nlohmann's object is
+ * a ``std::map``, so asking costs a tree walk per property -- twice over, as
+ * the value then has to be fetched. Walking also detects an unknown key on
+ * the way, which is why there is no separate pass for that.
+ *
+ * NOTE (mristin):
+ * We take \p map_of_properties in, instead of letting \p on_property work on
+ * the JSON name of the property, because we want the class to dispatch with
+ * a hard-wired ``switch`` whose branches assign the local variables of
+ * the caller.
+ *
+ * A ``switch`` needs an integral constant, and C++ can not switch on a string,
+ * so the name has to be translated into a literal of the property enumeration
+ * first. We do that here rather than in the class so that the translation, and
+ * the error reported when the name matches no property at all, are written
+ * once instead of once per class.
+ *
+ * \param json object whose properties are to be parsed
+ * \param map_of_properties maps the JSON name of a property to its literal
+ * \param additional_properties if not set, refuse a key which matches
+ * no property
+ * \param on_property parses the value of the recognized property
+ * \return the error, if the parsing failed
+ */
+template <typename EnumT, typename OnPropertyT>
+common::optional<DeserializationError> ParseProperties(
+  const nlohmann::json& json,
+  const std::unordered_map<std::string, EnumT>& map_of_properties,
+  bool additional_properties,
+  const OnPropertyT& on_property
+) {
+  #ifdef DEBUG
+  if (!json.is_object()) {
+    throw std::logic_error(
+      "Unexpected non-object in ParseProperties. "
+      "ParseProperties expects the caller to have checked that."
+    );
+  }
+  #endif
+
+  for (const auto& key_val : json.items()) {
+    auto it(
+      map_of_properties.find(key_val.key())
+    );
+
+    if (it == map_of_properties.end()) {
+      if (additional_properties) {
+        continue;
+      }
+
+      return DeserializationError(
+        common::Concat(
+          L"Unexpected additional property: ",
+          common::Utf8ToWstring(key_val.key())
+        )
+      );
+    }
+
+    common::optional<DeserializationError> error(
+      on_property(it->second, key_val.value())
+    );
+
+    if (error.has_value()) {
+      error->path.segments.emplace_front(
+        common::make_unique<PropertySegment>(
+          common::Utf8ToWstring(key_val.key())
+        )
+      );
+
+      return error;
+    }
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Check that \p json is a JSON object.
+ *
+ * \param json value to be checked
+ * \return the error, if \p json is anything else
+ */
+common::optional<DeserializationError> CheckJsonObject(
+  const nlohmann::json& json
+) {
+  if (!json.is_object()) {
+    return DeserializationError(
+      common::Concat(
+        L"Expected an object, but got: ",
+        common::Utf8ToWstring(json.type_name())
+      )
+    );
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Check that \p json is an object whose model type is \p expected.
+ *
+ * The model type is compared as the string which came on the wire. That refuses
+ * a value of the wrong type just as well as parsing it would, and costs neither
+ * a conversion to a wide string nor the allocation which goes with it.
+ *
+ * \param json value expected to be an object carrying a model type
+ * \param expected model type of the class
+ * \return the error, if \p json does not bear \p expected
+ */
+common::optional<DeserializationError> CheckModelType(
+  const nlohmann::json& json,
+  const char* expected
+) {
+  const std::string* model_type;
+  common::optional<DeserializationError> error;
+
+  std::tie(
+    model_type,
+    error
+  ) = GetModelTypeFrom(json);
+
+  if (error.has_value()) {
+    return error;
+  }
+
+  if (*model_type != expected) {
+    return DeserializationError(
+      common::Concat(
+        L"Expected model type '",
+        common::Utf8ToWstring(expected),
+        L"', but got: ",
+        common::Utf8ToWstring(*model_type)
+      )
+    );
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Assign the value parsed to \p target, or give out the error of the parse.
+ *
+ * We deliberately take the *result* of a parse instead of the JSON value and
+ * the function which parses it. The item parsers of a tuple vary both in number
+ * and in type, so no signature taking the parser could serve every parse;
+ * taking the result lets this single function serve all of them.
+ *
+ * \param target variable to be assigned the value parsed
+ * \param parsed result of the parse
+ * \return the error, if the parse failed
+ */
+template <typename T>
+common::optional<DeserializationError> ParseInto(
+  common::optional<T>& target,
+  std::pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >&& parsed
+) {
+  if (parsed.second.has_value()) {
+    return std::move(parsed.second);
+  }
+
+  target = std::move(parsed.first);
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Dispatch the deserialization for an instance
+ * of types::IItem.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the deserialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IItem>
+  >,
+  common::optional<DeserializationError>
+> DeserializeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Parse the properties of an instance of types::ISomeItem.
+ *
+ * The model type, if the class carries one, is expected to have been verified
+ * by the caller, which is what lets a dispatcher avoid verifying it twice.
+ *
+ * \param json object whose properties are to be parsed
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISomeItem>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfSomeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Dispatch the deserialization for an instance
+ * of types::ISomeItem.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the deserialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISomeItem>
+  >,
+  common::optional<DeserializationError>
+> DeserializeSomeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Parse the properties of an instance of types::ISpecialItem.
+ *
+ * The model type, if the class carries one, is expected to have been verified
+ * by the caller, which is what lets a dispatcher avoid verifying it twice.
+ *
+ * \param json object whose properties are to be parsed
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfSpecialItem(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Deserialize \p json to an instance of types::ISpecialItem.
+ *
+ * No dispatch is performed. The model type, if the class carries one, is
+ * verified here, since the caller has not read it.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> DeserializeSpecialItem(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Parse the properties of an instance of types::IContainer.
+ *
+ * The model type, if the class carries one, is expected to have been verified
+ * by the caller, which is what lets a dispatcher avoid verifying it twice.
+ *
+ * \param json object whose properties are to be parsed
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfContainer(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Deserialize \p json to an instance of types::IContainer.
+ *
+ * No dispatch is performed. The model type, if the class carries one, is
+ * verified here, since the caller has not read it.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> DeserializeContainer(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Parse the properties of an instance of types::IWrapper.
+ *
+ * The model type, if the class carries one, is expected to have been verified
+ * by the caller, which is what lets a dispatcher avoid verifying it twice.
+ *
+ * \param json object whose properties are to be parsed
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfWrapper(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+/**
+ * \brief Deserialize \p json to an instance of types::IWrapper.
+ *
+ * No dispatch is performed. The model type, if the class carries one, is
+ * verified here, since the caller has not read it.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \return the de-serialized instance, or an error, if any
+ */
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> DeserializeWrapper(
+  const nlohmann::json& json,
+  bool additional_properties
+);
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IItem>
+  >,
+  common::optional<DeserializationError>
+> DeserializeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  const std::string* model_type_str;
+  common::optional<DeserializationError> error;
+
+  std::tie(
+    model_type_str,
+    error
+  ) = GetModelTypeFrom(json);
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::IItem>
+    >(
+      std::move(*error)
+    );
+  }
+
+  common::optional<types::ModelType> model_type(
+    ModelTypeFromModelTypeString(*model_type_str)
+  );
+
+  if (!model_type.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<types::IItem>
+    >(
+      common::Concat(
+        L"The model type does not correspond to any known class: ",
+        common::Utf8ToWstring(*model_type_str)
+      )
+    );
+  }
+
+  switch (*model_type) {
+    case types::ModelType::kSomeItem:
+      return ParsePropertiesOfSomeItem<
+        types::IItem
+      >(json, additional_properties);
+    case types::ModelType::kSpecialItem:
+      return ParsePropertiesOfSpecialItem<
+        types::IItem
+      >(json, additional_properties);
+    default:
+      return NoInstanceAndDeserializationErrorWithCause<
+        std::shared_ptr<types::IItem>
+      >(
+        common::Concat(
+          L"The dispatch to the JSON de-serialization of "
+          L"types::IItem "
+          L"is not defined for model type: ",
+          common::Utf8ToWstring(*model_type_str)
+        )
+      );
+  }
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISomeItem>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfSomeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<std::wstring> the_name;
+
+  common::optional<std::wstring> the_nickname;
+
+  common::optional<DeserializationError> error(
+    ParseProperties(
+      json,
+      properties::kMapOfSomeItem,
+      additional_properties,
+      [&](
+        properties::OfSomeItem property,
+        const nlohmann::json& value
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfSomeItem::kName:
+            return ParseInto(
+              the_name,
+              DeserializeWstring(value)
+            );
+          case properties::OfSomeItem::kNickname:
+            return ParseInto(
+              the_nickname,
+              DeserializeWstring(value)
+            );
+          case properties::OfSomeItem::kModelType:
+            // NOTE (mristin):
+            // The model type has been verified before the loop, so there is nothing
+            // left to do with it here.
+            return common::nullopt;
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfSomeItem",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  if (!the_name.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property name is missing"
+    );
+  }
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::SomeItem(
+        std::move(*the_name),
+        std::move(the_nickname)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISomeItem>
+  >,
+  common::optional<DeserializationError>
+> DeserializeSomeItem(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  const std::string* model_type_str;
+  common::optional<DeserializationError> error;
+
+  std::tie(
+    model_type_str,
+    error
+  ) = GetModelTypeFrom(json);
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::ISomeItem>
+    >(
+      std::move(*error)
+    );
+  }
+
+  common::optional<types::ModelType> model_type(
+    ModelTypeFromModelTypeString(*model_type_str)
+  );
+
+  if (!model_type.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<types::ISomeItem>
+    >(
+      common::Concat(
+        L"The model type does not correspond to any known class: ",
+        common::Utf8ToWstring(*model_type_str)
+      )
+    );
+  }
+
+  switch (*model_type) {
+    case types::ModelType::kSomeItem:
+      return ParsePropertiesOfSomeItem<
+        types::ISomeItem
+      >(json, additional_properties);
+    case types::ModelType::kSpecialItem:
+      return ParsePropertiesOfSpecialItem<
+        types::ISomeItem
+      >(json, additional_properties);
+    default:
+      return NoInstanceAndDeserializationErrorWithCause<
+        std::shared_ptr<types::ISomeItem>
+      >(
+        common::Concat(
+          L"The dispatch to the JSON de-serialization of "
+          L"types::ISomeItem "
+          L"is not defined for model type: ",
+          common::Utf8ToWstring(*model_type_str)
+        )
+      );
+  }
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfSpecialItem(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<std::wstring> the_name;
+
+  common::optional<std::wstring> the_nickname;
+
+  common::optional<int64_t> the_level;
+
+  common::optional<DeserializationError> error(
+    ParseProperties(
+      json,
+      properties::kMapOfSpecialItem,
+      additional_properties,
+      [&](
+        properties::OfSpecialItem property,
+        const nlohmann::json& value
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfSpecialItem::kName:
+            return ParseInto(
+              the_name,
+              DeserializeWstring(value)
+            );
+          case properties::OfSpecialItem::kNickname:
+            return ParseInto(
+              the_nickname,
+              DeserializeWstring(value)
+            );
+          case properties::OfSpecialItem::kLevel:
+            return ParseInto(
+              the_level,
+              DeserializeInt64(value)
+            );
+          case properties::OfSpecialItem::kModelType:
+            // NOTE (mristin):
+            // The model type has been verified before the loop, so there is nothing
+            // left to do with it here.
+            return common::nullopt;
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfSpecialItem",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  if (!the_name.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property name is missing"
+    );
+  }
+
+  if (!the_level.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property level is missing"
+    );
+  }
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::SpecialItem(
+        std::move(*the_name),
+        std::move(*the_level),
+        std::move(the_nickname)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> DeserializeSpecialItem(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<DeserializationError> error(
+    CheckModelType(
+      json,
+      "SpecialItem"
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  return ParsePropertiesOfSpecialItem<T>(
+    json,
+    additional_properties
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfContainer(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::IItem>
+    >
+  > the_items;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::ISomeItem>
+    >
+  > the_some_items;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  > the_special_items;
+
+  common::optional<DeserializationError> error(
+    ParseProperties(
+      json,
+      properties::kMapOfContainer,
+      additional_properties,
+      [&](
+        properties::OfContainer property,
+        const nlohmann::json& value
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfContainer::kItems:
+            return ParseInto(
+              the_items,
+              DeserializeList<
+                std::shared_ptr<types::IItem>
+              >(
+                value,
+                additional_properties,
+                DeserializeItem
+              )
+            );
+          case properties::OfContainer::kSomeItems:
+            return ParseInto(
+              the_some_items,
+              DeserializeList<
+                std::shared_ptr<types::ISomeItem>
+              >(
+                value,
+                additional_properties,
+                DeserializeSomeItem
+              )
+            );
+          case properties::OfContainer::kSpecialItems:
+            return ParseInto(
+              the_special_items,
+              DeserializeList<
+                std::shared_ptr<types::ISpecialItem>
+              >(
+                value,
+                additional_properties,
+                DeserializeSpecialItem<
+                  types::ISpecialItem
+                >
+              )
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfContainer",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::IContainer>
+    >(
+      std::move(*error)
+    );
+  }
+
+  if (!the_items.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<types::IContainer>
+    >(
+      L"The required property items is missing"
+    );
+  }
+
+  if (!the_some_items.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<types::IContainer>
+    >(
+      L"The required property someItems is missing"
+    );
+  }
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<types::IContainer>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::Container(
+        std::move(*the_items),
+        std::move(*the_some_items),
+        std::move(the_special_items)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> DeserializeContainer(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<DeserializationError> error(
+    CheckJsonObject(json)
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::IContainer>
+    >(
+      std::move(*error)
+    );
+  }
+
+  return ParsePropertiesOfContainer(json, additional_properties);
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> ParsePropertiesOfWrapper(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<std::shared_ptr<types::IContainer> > the_container;
+
+  common::optional<DeserializationError> error(
+    ParseProperties(
+      json,
+      properties::kMapOfWrapper,
+      additional_properties,
+      [&](
+        properties::OfWrapper property,
+        const nlohmann::json& value
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfWrapper::kContainer:
+            return ParseInto(
+              the_container,
+              DeserializeContainer(
+                value,
+                additional_properties
+              )
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfWrapper",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::IWrapper>
+    >(
+      std::move(*error)
+    );
+  }
+
+  if (!the_container.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<types::IWrapper>
+    >(
+      L"The required property container is missing"
+    );
+  }
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<types::IWrapper>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::Wrapper(
+        std::move(*the_container)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> DeserializeWrapper(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  common::optional<DeserializationError> error(
+    CheckJsonObject(json)
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<types::IWrapper>
+    >(
+      std::move(*error)
+    );
+  }
+
+  return ParsePropertiesOfWrapper(json, additional_properties);
+}
+
+/**
+ * \brief De-serialize \p json and render the outcome as an expected value.
+ *
+ * \param json value to be de-serialized
+ * \param additional_properties if not set, check that \p json contains
+ * no additional properties
+ * \param deserialize de-serializes the value
+ * \return the de-serialized value, or the error
+ */
+template <typename T, typename DeserializeT>
+common::expected<
+  T,
+  DeserializationError
+> DeserializeFrom(
+  const nlohmann::json& json,
+  bool additional_properties,
+  const DeserializeT& deserialize
+) {
+  common::optional<T> instance;
+  common::optional<DeserializationError> error;
+
+  std::tie(
+    instance,
+    error
+  ) = deserialize(json, additional_properties);
+
+  if (instance.has_value()) {
+    return std::move(*instance);
+  }
+
+  if (!error.has_value()) {
+    throw std::logic_error(
+      "Unexpected null error when null instance."
+    );
+  }
+
+  return common::make_unexpected(
+    std::move(*error)
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IItem>,
+  DeserializationError
+> ItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IItem>
+  >(
+    json,
+    additional_properties,
+    DeserializeItem
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::ISomeItem>,
+  DeserializationError
+> SomeItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::ISomeItem>
+  >(
+    json,
+    additional_properties,
+    DeserializeSomeItem
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::ISpecialItem>,
+  DeserializationError
+> SpecialItemFrom(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::ISpecialItem>
+  >(
+    json,
+    additional_properties,
+    DeserializeSpecialItem<
+      types::ISpecialItem
+    >
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IContainer>,
+  DeserializationError
+> ContainerFrom(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IContainer>
+  >(
+    json,
+    additional_properties,
+    DeserializeContainer
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IWrapper>,
+  DeserializationError
+> WrapperFrom(
+  const nlohmann::json& json,
+  bool additional_properties
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IWrapper>
+  >(
+    json,
+    additional_properties,
+    DeserializeWrapper
+  );
+}
+
+// endregion De-serialization
+
+// region Serialization
+
+/**
+ * \brief Represent a serialization error.
+ *
+ * We use this error internally to avoid unnecessary stack unwinding,
+ * but throw the \ref SerializationException at the final site of
+ * the serialization for the user.
+ */
+struct SerializationError {
+  /**
+   * Human-readable description of the error
+   */
+  std::wstring cause;
+
+  /**
+   * Path to the value that caused the error
+   */
+  iteration::Path path;
+
+  explicit SerializationError(
+    std::wstring a_cause
+  ) : cause(std::move(a_cause)) {
+    // Intentionally empty.
+  }
+};  // struct SerializationError
+
+// region SerializationException
+
+std::string RenderSerializationErrorMessage(
+  const std::wstring& cause,
+  const iteration::Path& path
+) {
+  return common::WstringToUtf8(
+    common::Concat(
+      L"Serialization failed at ",
+      path.ToWstring(),
+      L": ",
+      cause
+    )
+  );
+}
+
+SerializationException::SerializationException(
+  std::wstring cause,
+  iteration::Path path
+) :
+  cause_(std::move(cause)),
+  path_(std::move(path)),
+  msg_(RenderSerializationErrorMessage(cause, path)) {
+  // Intentionally empty.
+}
+
+const char* SerializationException::what() const noexcept {
+  return msg_.c_str();
+}
+
+const std::wstring& SerializationException::cause() const noexcept {
+  return cause_;
+}
+
+const iteration::Path& SerializationException::path() const noexcept {
+  return path_;
+}
+
+// endregion SerializationException
+
+/**
+ * Serialize the given boolean to a JSON value.
+ */
+nlohmann::json SerializeBool(
+  bool value
+) {
+  return value;
+}
+
+/**
+ * \brief Serialize the given number to a JSON value.
+ *
+ * We verify that the integer is within the range representable by 64-bit floats
+ * for interoperability with other de-serializers.
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeInt64(int64_t value) {
+  if (
+    value < -9007199254740991L
+    || value > 9007199254740991L
+  ) {
+    const std::wstring message = common::Concat(
+      L"The integer ",
+      std::to_wstring(value),
+      L" can not be serialized to JSON "
+      L"as it is outside the range [-2^53 + 1, 2^53 - 1] and can not "
+      L"be exactly represented as a 64-bit floating point number."
+    );
+
+    return std::make_pair<
+      common::optional<nlohmann::json>,
+      common::optional<SerializationError>
+    >(
+      common::nullopt,
+      common::make_optional<SerializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::make_optional<nlohmann::json>(value),
+    common::nullopt
+  );
+}
+
+/**
+ * \brief Serialize the given floating-point number to a JSON value.
+ *
+ * JSON knows neither an infinity nor a not-a-number, so we refuse to serialize
+ * them instead of silently writing them out as ``null``.
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeDouble(double value) {
+  if (!std::isfinite(value)) {
+    const std::wstring message = common::Concat(
+      L"The floating-point number ",
+      std::to_wstring(value),
+      L" can not be serialized to JSON as JSON knows no infinity "
+      L"and no not-a-number."
+    );
+
+    return std::make_pair<
+      common::optional<nlohmann::json>,
+      common::optional<SerializationError>
+    >(
+      common::nullopt,
+      common::make_optional<SerializationError>(
+        message
+      )
+    );
+  }
+
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::make_optional<nlohmann::json>(value),
+    common::nullopt
+  );
+}
+
+/**
+ * Serialize the given text to a JSON value.
+ */
+nlohmann::json SerializeWstring(
+  const std::wstring& text
+) {
+  return nlohmann::json(
+    common::WstringToUtf8(text)
+  );
+}
+
+/**
+ * Serialize the given bytes to a JSON value.
+ */
+nlohmann::json SerializeByteArray(
+  const std::vector<std::uint8_t>& bytes
+) {
+  return nlohmann::json(
+    stringification::Base64Encode(bytes)
+  );
+}
+
+/**
+ * Serialize the given list to a JSON array where item serialization might fail.
+ */
+template<typename T, typename FallibleSerializeItemT>
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeListWithFallible(
+  const std::vector<T>& list,
+  FallibleSerializeItemT&& fallible_serialize_item
+) {
+  nlohmann::json serialized = nlohmann::json::array();
+
+  serialized.get_ptr<nlohmann::json::array_t*>()->reserve(
+    list.size()
+  );
+
+  size_t index = 0;
+
+  for (const T& item : list) {
+    common::optional<nlohmann::json> json_item;
+    common::optional<SerializationError> error;
+
+    std::tie(
+      json_item,
+      error
+    ) = fallible_serialize_item(item);
+
+    if (error.has_value()) {
+      error->path.segments.emplace_front(
+        common::make_unique<iteration::IndexSegment>(
+          index
+        )
+      );
+
+      return std::make_pair<
+        common::optional<nlohmann::json>,
+        common::optional<SerializationError>
+      >(
+        common::nullopt,
+        std::move(error)
+      );
+    }
+
+    serialized.emplace_back(
+      std::move(*json_item)
+    );
+
+    ++index;
+  }
+
+  return std::make_pair(
+    std::move(serialized),
+    common::nullopt
+  );
+}
+
+/**
+ * Serialize the given list to a JSON array where item serialization can not fail.
+ */
+template<typename T, typename InfallibleSerializeItemT>
+nlohmann::json SerializeListWithInfallible(
+  const std::vector<T>& list,
+  InfallibleSerializeItemT&& infallible_serialize_item
+) {
+  nlohmann::json serialized = nlohmann::json::array();
+
+  serialized.get_ptr<nlohmann::json::array_t*>()->reserve(
+    list.size()
+  );
+
+  for (const T& item : list) {
+    serialized.emplace_back(
+      infallible_serialize_item(item)
+    );
+  }
+
+  return serialized;
+}
+
+/**
+ * Serialize the given list of instances to a JSON array where item
+ * serialization might fail.
+ *
+ * The items are pointers, which we dereference for the item serializer.
+ */
+template<typename T, typename FallibleSerializeItemT>
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeListOfInstancesWithFallible(
+  const std::vector<std::shared_ptr<T> >& list,
+  FallibleSerializeItemT&& fallible_serialize_item
+) {
+  nlohmann::json serialized = nlohmann::json::array();
+
+  serialized.get_ptr<nlohmann::json::array_t*>()->reserve(
+    list.size()
+  );
+
+  size_t index = 0;
+
+  for (const std::shared_ptr<T>& item : list) {
+    common::optional<nlohmann::json> json_item;
+    common::optional<SerializationError> error;
+
+    std::tie(
+      json_item,
+      error
+    ) = fallible_serialize_item(*item);
+
+    if (error.has_value()) {
+      error->path.segments.emplace_front(
+        common::make_unique<iteration::IndexSegment>(
+          index
+        )
+      );
+
+      return std::make_pair<
+        common::optional<nlohmann::json>,
+        common::optional<SerializationError>
+      >(
+        common::nullopt,
+        std::move(error)
+      );
+    }
+
+    serialized.emplace_back(
+      std::move(*json_item)
+    );
+
+    ++index;
+  }
+
+  return std::make_pair(
+    std::move(serialized),
+    common::nullopt
+  );
+}
+
+/**
+ * Serialize the given list of instances to a JSON array where item
+ * serialization can not fail.
+ *
+ * The items are pointers, which we dereference for the item serializer.
+ */
+template<typename T, typename InfallibleSerializeItemT>
+nlohmann::json SerializeListOfInstancesWithInfallible(
+  const std::vector<std::shared_ptr<T> >& list,
+  InfallibleSerializeItemT&& infallible_serialize_item
+) {
+  nlohmann::json serialized = nlohmann::json::array();
+
+  serialized.get_ptr<nlohmann::json::array_t*>()->reserve(
+    list.size()
+  );
+
+  for (const std::shared_ptr<T>& item : list) {
+    serialized.emplace_back(
+      infallible_serialize_item(*item)
+    );
+  }
+
+  return serialized;
+}
+
+/**
+ * \brief Give out a failed serialization with \p cause as its message.
+ *
+ * \param cause human-readable description of the failure
+ * \return no value, and the error
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> NoJsonAndSerializationErrorWithCause(
+  std::wstring cause
+) {
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::nullopt,
+    common::make_optional<SerializationError>(
+      std::move(cause)
+    )
+  );
+}
+
+/**
+ * \brief Give out a failed serialization with \p error.
+ *
+ * \param error of the serialization
+ * \return no value, and the error
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> NoJsonAndSerializationError(
+  SerializationError error
+) {
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::nullopt,
+    common::make_optional<SerializationError>(
+      std::move(error)
+    )
+  );
+}
+
+/**
+ * \brief Put the value serialized under \p key of \p result, or give out
+ * the error of the serialization, marked with \p property.
+ *
+ * We deliberately take the *result* of a serialization instead of the value
+ * and the function which serializes it. The item serializers of a tuple vary
+ * both in number and in type, so no signature taking the serializer could
+ * serve every serialization; taking the result lets this single function
+ * serve all of them.
+ *
+ * \param result object to be written to
+ * \param key of the property in the JSON object
+ * \param property which the key stands for, for the path of the error
+ * \param serialized result of the serialization
+ * \return the error, if the serialization failed
+ */
+common::optional<SerializationError> SerializeInto(
+  nlohmann::json& result,
+  const char* key,
+  iteration::Property property,
+  std::pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >&& serialized
+) {
+  if (serialized.second.has_value()) {
+    serialized.second->path.segments.emplace_front(
+      common::make_unique<iteration::PropertySegment>(property)
+    );
+
+    return std::move(serialized.second);
+  }
+
+  result[key] = std::move(*serialized.first);
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Give the value out in the shape of a serialization which can fail.
+ *
+ * ``SerializeTuple{N}`` takes one item serializer per item, and the items of
+ * a tuple differ in kind, so some of them can fail and some of them can not.
+ * Lifting the ones which can not is what lets the tuple treat all of them
+ * alike, without a normalizing lambda per kind at the call site.
+ */
+template <typename T>
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> AsFallible(T&& value) {
+  return std::make_pair(
+    common::make_optional<nlohmann::json>(std::forward<T>(value)),
+    common::nullopt
+  );
+}
+
+/**
+ * @copybrief AsFallible
+ *
+ * The serialization could already fail, so there is nothing to lift.
+ */
+inline std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> AsFallible(
+  std::pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >&& serialized
+) {
+  return std::move(serialized);
+}
+
+/**
+ * \brief Serialize \p that instance to a JSON value, dispatching on its
+ * model type.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeIClass(
+  const types::IClass& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::ISomeItem to a JSON value.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value
+ */
+nlohmann::json SerializeConcreteSomeItem(
+  const types::ISomeItem& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::ISpecialItem to a JSON value.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeSpecialItem(
+  const types::ISpecialItem& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::IContainer to a JSON value.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeContainer(
+  const types::IContainer& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::IWrapper to a JSON value.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeWrapper(
+  const types::IWrapper& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::IItem to a JSON value,
+ * dispatching on its model type.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeItem(
+  const types::IItem& that
+);
+
+/**
+ * \brief Serialize \p that instance of types::ISomeItem to a JSON value,
+ * dispatching on its model type.
+ *
+ * \param that instance to be serialized
+ * \return the JSON value , or an error, if any
+ */
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeSomeItem(
+  const types::ISomeItem& that
+);
+
+nlohmann::json SerializeConcreteSomeItem(
+  const types::ISomeItem& that
+) {
+  nlohmann::json result = nlohmann::json::object();
+
+  result["name"] = SerializeWstring(
+    that.name()
+  );
+
+  const common::optional<std::wstring>& maybe_nickname(
+    that.nickname()
+  );
+  if (maybe_nickname.has_value()) {
+    result["nickname"] = SerializeWstring(
+      *maybe_nickname
+    );
+  }
+
+  result["modelType"] = "SomeItem";
+
+  return result;
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeSpecialItem(
+  const types::ISpecialItem& that
+) {
+  nlohmann::json result = nlohmann::json::object();
+
+  common::optional<SerializationError> error;
+
+  result["name"] = SerializeWstring(
+    that.name()
+  );
+
+  const common::optional<std::wstring>& maybe_nickname(
+    that.nickname()
+  );
+  if (maybe_nickname.has_value()) {
+    result["nickname"] = SerializeWstring(
+      *maybe_nickname
+    );
+  }
+
+  error = SerializeInto(
+    result,
+    "level",
+    iteration::Property::kLevel,
+    SerializeInt64(
+      that.level()
+    )
+  );
+  if (error.has_value()) {
+    return NoJsonAndSerializationError(
+      std::move(*error)
+    );
+  }
+
+  result["modelType"] = "SpecialItem";
+
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::make_optional<nlohmann::json>(std::move(result)),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeContainer(
+  const types::IContainer& that
+) {
+  nlohmann::json result = nlohmann::json::object();
+
+  common::optional<SerializationError> error;
+
+  error = SerializeInto(
+    result,
+    "items",
+    iteration::Property::kItems,
+    SerializeListOfInstancesWithFallible(
+      that.items(),
+      SerializeItem
+    )
+  );
+  if (error.has_value()) {
+    return NoJsonAndSerializationError(
+      std::move(*error)
+    );
+  }
+
+  error = SerializeInto(
+    result,
+    "someItems",
+    iteration::Property::kSomeItems,
+    SerializeListOfInstancesWithFallible(
+      that.some_items(),
+      SerializeSomeItem
+    )
+  );
+  if (error.has_value()) {
+    return NoJsonAndSerializationError(
+      std::move(*error)
+    );
+  }
+
+  const common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& maybe_special_items(
+    that.special_items()
+  );
+  if (maybe_special_items.has_value()) {
+    error = SerializeInto(
+      result,
+      "specialItems",
+      iteration::Property::kSpecialItems,
+      SerializeListOfInstancesWithFallible(
+        *maybe_special_items,
+        SerializeSpecialItem
+      )
+    );
+    if (error.has_value()) {
+      return NoJsonAndSerializationError(
+        std::move(*error)
+      );
+    }
+  }
+
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::make_optional<nlohmann::json>(std::move(result)),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeWrapper(
+  const types::IWrapper& that
+) {
+  nlohmann::json result = nlohmann::json::object();
+
+  common::optional<SerializationError> error;
+
+  error = SerializeInto(
+    result,
+    "container",
+    iteration::Property::kContainer,
+    SerializeContainer(
+      *(that.container())
+    )
+  );
+  if (error.has_value()) {
+    return NoJsonAndSerializationError(
+      std::move(*error)
+    );
+  }
+
+  return std::make_pair<
+    common::optional<nlohmann::json>,
+    common::optional<SerializationError>
+  >(
+    common::make_optional<nlohmann::json>(std::move(result)),
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeItem(
+  const types::IItem& that
+) {
+  // NOTE (mristin):
+  // The dynamic casts are necessary due to virtual inheritance. Otherwise,
+  // we would have used static casts.
+
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return AsFallible(
+        SerializeConcreteSomeItem(
+          dynamic_cast<const types::ISomeItem&>(that)
+        )
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItem(
+        dynamic_cast<const types::ISpecialItem&>(that)
+      );
+    default: {
+      std::string message = common::Concat(
+        "Unexpected model type: ",
+        std::to_string(
+          static_cast<std::uint32_t>(
+            that.model_type()
+          )
+        )
+      );
+
+      throw std::invalid_argument(message);
+    }
+  };
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeSomeItem(
+  const types::ISomeItem& that
+) {
+  // NOTE (mristin):
+  // The dynamic casts are necessary due to virtual inheritance. Otherwise,
+  // we would have used static casts.
+
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return AsFallible(
+        SerializeConcreteSomeItem(that)
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItem(
+        dynamic_cast<const types::ISpecialItem&>(that)
+      );
+    default: {
+      std::string message = common::Concat(
+        "Unexpected model type: ",
+        std::to_string(
+          static_cast<std::uint32_t>(
+            that.model_type()
+          )
+        )
+      );
+
+      throw std::invalid_argument(message);
+    }
+  };
+}
+
+std::pair<
+  common::optional<nlohmann::json>,
+  common::optional<SerializationError>
+> SerializeIClass(
+  const types::IClass& that
+) {
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return AsFallible(
+        SerializeConcreteSomeItem(
+          dynamic_cast<const types::ISomeItem&>(that)
+        )
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItem(
+        dynamic_cast<const types::ISpecialItem&>(that)
+      );
+    case types::ModelType::kContainer:
+      return SerializeContainer(
+        dynamic_cast<const types::IContainer&>(that)
+      );
+    case types::ModelType::kWrapper:
+      return SerializeWrapper(
+        dynamic_cast<const types::IWrapper&>(that)
+      );
+    default: {
+      std::string message = common::Concat(
+        "Unexpected model type: ",
+        std::to_string(
+          static_cast<std::uint32_t>(
+            that.model_type()
+          )
+        )
+      );
+
+      throw std::invalid_argument(message);
+    }
+  };
+}
+
+nlohmann::json Serialize(
+  const types::IClass& that
+) {
+  common::optional<nlohmann::json> result;
+  common::optional<SerializationError> error;
+
+  std::tie(
+    result,
+    error
+  ) = SerializeIClass(that);
+
+  if (error.has_value()) {
+    throw SerializationException(
+      std::move(error->cause),
+      std::move(error->path)
+    );
+  }
+
+  return std::move(*result);
+}
+
+// endregion Serialization
+
+}  // namespace jsonization
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/pattern.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/pattern.cpp
new file mode 100644
index 000000000..14eb2451e
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/pattern.cpp
@@ -0,0 +1,15 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/pattern.hpp"
+#include "dummy/revm.hpp"
+
+namespace dummy {
+namespace pattern {
+
+}  // namespace pattern
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/revm.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/revm.cpp
new file mode 100644
index 000000000..9c3d9aa0d
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/revm.cpp
@@ -0,0 +1,861 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/revm.hpp"
+
+#pragma warning(push, 0)
+#include <algorithm>
+#include <iomanip>
+#include <sstream>
+#pragma warning(pop)
+
+namespace dummy {
+namespace revm {
+
+/**
+ * Represent the character such that it can be printed in the console.
+ *
+ * To that end, we escape the character if it is out of the printable ASCII set.
+ *
+ * This function is mostly meant for debugging purposes.
+ */
+std::string RepresentWCharacter(wchar_t character) {
+  switch (character) {
+    case L'\\':return "\\\\";
+    case L'"':return "\\\"";
+    case L'\'':return "\\'";
+    case L'\t':return "\\t";
+    case L'\n':return "\\n";
+    case L'\r':return "\\r";
+    default: break;
+  }
+
+  if (26 <= character && character <= 126) {
+    return std::string(1, static_cast<char>(character));
+  }
+
+  static const char* digits = "0123456789ABCDEF";
+  size_t digit_count = sizeof(wchar_t) * 2;
+
+  std::string result;
+  result.resize(digit_count + 2);
+  result[0] = L'\\';
+  result[1] = L'u';
+
+  for (size_t i = 0, j = (digit_count - 1) * 4; i < digit_count; ++i, j -= 4) {
+    const size_t digit_i = (character >> j) & 0x0f;
+    result[i + 2] = digits[digit_i];
+  }
+
+  return result;
+}
+
+/**
+ * Represent the wide string for debugging purposes where it is printed to the console.
+ *
+ * To that end, we escape the individual characters if they are out of printable ASCII
+ * set.
+ */
+std::string RepresentWString(const std::wstring& text) {
+  std::vector<std::string> parts;
+  parts.reserve(text.size());
+  for (const wchar_t character : text) {
+    parts.emplace_back(RepresentWCharacter(character));
+  }
+
+  size_t size = 0;
+  for (const std::string& part : parts) {
+    size += part.size();
+  }
+
+  std::string result;
+  result.reserve(size);
+  for (const std::string& part : parts) {
+    result.append(part);
+  }
+  return result;
+}
+
+InstructionChar::InstructionChar(
+  wchar_t a_character
+) :
+  character(a_character) {
+  // Intentionally empty.
+}
+
+InstructionKind InstructionChar::kind() const {
+  return InstructionKind::Char;
+}
+
+std::string to_string(const InstructionChar& instruction) {
+  return common::Concat(
+    "char '",
+    RepresentWCharacter(instruction.character),
+    "'"
+  );
+}
+
+Range::Range(
+  wchar_t a_first,
+  wchar_t a_last
+) :
+  first(a_first),
+  last(a_last) {
+  // NOTE (mristin):
+  // We are aware that exceptions in constructors should be avoided to prevent
+  // bug related to uninitialized object state. However, in this case, we do not
+  // see any risk for such a mistake.
+  if (a_first > a_last) {
+    throw std::invalid_argument(
+      common::Concat(
+        "The first character in a character range, ",
+        RepresentWCharacter(a_first),
+        ", is larger than the last character in the range, ",
+        RepresentWCharacter(a_last)
+      )
+    );
+  }
+}
+
+std::string to_string(const Range& range) {
+  if (range.first == range.last) {
+    return RepresentWCharacter(range.first);
+  }
+
+  return common::Concat(
+    RepresentWCharacter(range.first),
+    "-",
+    RepresentWCharacter(range.last)
+  );
+}
+
+InstructionSet::InstructionSet(
+  std::vector<Range> a_ranges
+) :
+  ranges(std::move(a_ranges)) {
+  // NOTE (mristin):
+  // We are aware that exceptions in constructors should be avoided to prevent
+  // bug related to uninitialized object state. However, in this case, we do not
+  // see any risk for such a mistake.
+  if (ranges.empty()) {
+    throw std::invalid_argument(
+      "Unexpected NotSet instruction with empty ranges"
+    );
+  }
+
+  for (size_t i = 1; i < ranges.size(); ++i) {
+    if (ranges[i - 1].last >= ranges[i].first) {
+      throw std::invalid_argument(
+        common::Concat(
+          "The ranges for an InstructionSet are unexpectedly either "
+          "not sorted or overlapping. The range at index ",
+          std::to_string(i - 1),
+          " is ",
+          to_string(ranges[i - 1]),
+          " and the range at index ",
+          std::to_string(i),
+          " is ",
+          to_string(ranges[i])
+        )
+      );
+    }
+  }
+}
+
+InstructionKind InstructionSet::kind() const {
+  return InstructionKind::Set;
+}
+
+std::string to_string(const InstructionSet& instruction) {
+  std::stringstream ss;
+  ss << "set '";
+
+  for (const auto& range : instruction.ranges) {
+    ss << to_string(range);
+  }
+
+  ss << "'";
+  return ss.str();
+}
+
+InstructionNotSet::InstructionNotSet(
+  std::vector<Range> a_ranges
+) :
+  ranges(std::move(a_ranges)) {
+  // NOTE (mristin):
+  // We are aware that exceptions in constructors should be avoided to prevent
+  // bug related to uninitialized object state. However, in this case, we do not
+  // see any risk for such a mistake.
+  if (ranges.empty()) {
+    throw std::invalid_argument(
+      "Unexpected NotSet instruction with empty ranges"
+    );
+  }
+
+  for (size_t i = 1; i < ranges.size(); ++i) {
+    if (ranges[i - 1].last >= ranges[i].first) {
+      throw std::invalid_argument(
+        common::Concat(
+          "The ranges for an InstructionNotSet are unexpectedly either "
+          "not sorted or overlapping. The range at index ",
+          std::to_string(i - 1),
+          " is ",
+          to_string(ranges[i - 1]),
+          " and the range at index ",
+          std::to_string(i),
+          " is ",
+          to_string(ranges[i])
+        )
+      );
+    }
+  }
+}
+
+InstructionKind InstructionNotSet::kind() const {
+  return InstructionKind::NotSet;
+}
+
+std::string to_string(const InstructionNotSet& instruction) {
+  std::stringstream ss;
+  ss << "not-set '";
+
+  for (const auto& range : instruction.ranges) {
+    ss << to_string(range);
+  }
+
+  ss << "'";
+  return ss.str();
+}
+
+InstructionKind InstructionAny::kind() const {
+  return InstructionKind::Any;
+}
+
+std::string to_string(const InstructionAny&) {
+  return "any";
+}
+
+InstructionKind InstructionMatch::kind() const {
+  return InstructionKind::Match;
+}
+
+std::string to_string(const InstructionMatch&) {
+  return "match";
+}
+
+InstructionJump::InstructionJump(
+  size_t a_target
+) :
+  target(a_target) {
+  // Intentionally empty.
+}
+
+InstructionKind InstructionJump::kind() const {
+  return InstructionKind::Jump;
+}
+
+std::string to_string(const InstructionJump& instruction) {
+  return common::Concat(
+    "jump ",
+    std::to_string(instruction.target)
+  );
+}
+
+InstructionSplit::InstructionSplit(
+  size_t a_first_target,
+  size_t a_second_target
+) :
+  first_target(a_first_target),
+  second_target(a_second_target) {
+  // Intentionally empty.
+}
+
+InstructionKind InstructionSplit::kind() const {
+  return InstructionKind::Split;
+}
+
+std::string to_string(const InstructionSplit& instruction) {
+  return common::Concat(
+    "split ",
+      std::to_string(instruction.first_target),
+      ", ",
+      std::to_string(instruction.second_target)
+  );
+}
+
+InstructionKind InstructionEnd::kind() const {
+  return InstructionKind::End;
+}
+
+std::string to_string(const InstructionEnd&) {
+  return "end";
+}
+
+std::string to_string(const Instruction& instruction) {
+  switch (instruction.kind()) {
+    case InstructionKind::Char:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionChar&
+        >(instruction)
+      );
+
+    case InstructionKind::Set:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionSet&
+        >(instruction)
+      );
+
+    case InstructionKind::NotSet:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionNotSet&
+        >(instruction)
+      );
+
+    case InstructionKind::Any:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionAny&
+        >(instruction)
+      );
+
+    case InstructionKind::Match:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionMatch&
+        >(instruction)
+      );
+
+    case InstructionKind::Jump:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionJump&
+        >(instruction)
+      );
+
+    case InstructionKind::Split:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionSplit&
+        >(instruction)
+      );
+
+    case InstructionKind::End:
+      return to_string(
+        static_cast<   // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const InstructionEnd&
+        >(instruction)
+      );
+
+    default:
+      throw std::logic_error(
+        common::Concat(
+          "Unhandled instruction kind: ",
+          std::to_string(
+            static_cast<std::uint8_t>(instruction.kind())
+          )
+        )
+      );
+  }
+}
+
+std::string to_string(
+  const std::vector<std::unique_ptr<Instruction> >& instructions
+) {
+  std::stringstream ss;
+  for (size_t i = 0; i < instructions.size(); ++i) {
+    ss
+      << std::setw(4) << i << ": "
+      << to_string(*instructions[i]) << std::endl;
+  }
+
+  return ss.str();
+}
+
+bool CharacterInRanges(
+  const std::vector<Range>& ranges,
+  wchar_t character
+) {
+  if (ranges.empty()) {
+    return false;
+  }
+
+  if (ranges.size() == 1) {
+    return (ranges[0].first <= character && character <= ranges[0].last);
+  }
+
+  // Binary search
+  size_t begin = 0;
+  size_t end = ranges.size();
+
+  while (true) {
+    if (begin == end) {
+      return false;
+    }
+
+    // NOTE (mristin):
+    // Most implementations of the binary search are buggy, see:
+    // https://en.wikipedia.org/wiki/Binary_search_algorithm#Implementation_issues.
+    //
+    // We try to avert some of the bugs by explicitly handling the case where there
+    // are at most 3 elements in the segment, so we stop here instead of proceeding
+    // recursively.
+    if (end - begin <= 3) {
+      for (size_t i = begin; i < end; ++i) {
+        const Range& range = ranges[i];
+        if (range.first <= character && character <= range.last) {
+          return true;
+        }
+      }
+      return false;
+    }
+
+    const size_t middle = (begin + end) / 2;
+    const Range& range = ranges[middle];
+    if (character < range.first) {
+      end = middle;
+    } else if (character > range.last) {
+      begin = middle;
+    } else {
+      return true;
+    }
+  }
+}
+
+/**
+ * Keep track of the threads currently being executed.
+ */
+class ThreadList {
+ public:
+  explicit ThreadList(size_t program_size) {
+    has_.resize(program_size, false);
+    items_.reserve(program_size);
+  }
+
+  /**
+   * Add a new thread for the given program counter if it is not already in the list.
+   */
+  void Spawn(size_t program_counter) {
+    #ifdef DEBUG
+    if (program_counter >= has_.size()) {
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected spawning of a thread at the program counter ",
+          std::to_string(program_counter),
+          " since the program size was indicated to be ",
+          std::to_string(has_.size())
+        )
+      );
+    }
+    #endif
+
+    if (has_[program_counter]) {
+      return;
+    }
+
+    has_[program_counter] = true;
+    items_.push_back(program_counter);
+  }
+
+  bool Empty() const {
+    return items_.empty();
+  }
+
+  /**
+   * Pop the thread from the back, returning its program counter.
+   *
+   * The order of the threads is not guaranteed.
+   */
+  size_t Pop() {
+    #ifdef DEBUG
+    if (items_.empty()) {
+      throw std::logic_error(
+        "You tried to pop from an empty thread list."
+        );
+    }
+    #endif
+
+    const size_t program_counter = items_.back();
+    items_.pop_back();
+    has_[program_counter] = false;
+    return program_counter;
+  }
+
+  /**
+   * Clear the thread list, keeping its memory capacity.
+   */
+  void Clear() {
+    std::fill(has_.begin(), has_.end(), false);
+    items_.clear();
+  }
+
+  /**
+   * Return the program counters corresponding to the spawned threads.
+   */
+  const std::vector<size_t>& Items() const {
+    return items_;
+  };
+
+ private:
+  /**
+   * Keep track of the program counters corresponding to the threads so that we can
+   * avoid the duplicate threads.
+   */
+  std::vector<bool> has_;
+
+  /**
+   * Keep track of the active threads.
+   */
+  std::vector<size_t> items_;
+};
+
+std::string to_string(const ThreadList& thread_list) {
+  if (thread_list.Empty()) {
+    return "[]";
+  }
+
+  std::vector<size_t> items(thread_list.Items());
+  std::sort(items.begin(), items.end());
+
+  std::stringstream ss;
+  ss << "[";
+  ss << std::to_string(items[0]);
+
+  for (size_t i = 1; i < items.size(); ++i) {
+    ss << ", " << items[i];
+  }
+  ss << "]";
+
+  return ss.str();
+}
+
+/**
+ * Try to match the program against the text.
+ *
+ * @return true if the text matches
+ */
+bool Match(
+  const std::vector<std::unique_ptr<Instruction> >& program,
+  const std::wstring& text
+) {
+  if (program.empty()) {
+    return false;
+  }
+
+  // NOTE (mristin):
+  // We validate at the beginning so that we can avoid checks in
+  // the instruction loops.
+  for (size_t i = 0; i < program.size(); ++i) {
+    const Instruction& instruction = *program[i];
+
+    switch (instruction.kind()) {
+      case InstructionKind::Jump: {
+        const auto& instruction_jump(
+          static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+            const InstructionJump&
+          >(
+            instruction
+          )
+        );
+
+        if (instruction_jump.target >= program.size()) {
+          throw std::invalid_argument(
+            common::Concat(
+              "Unexpected jump beyond the end of the program. Program has ",
+              std::to_string(program.size()),
+              " instruction(s), but the instruction ",
+              std::to_string(i),
+              " wants to jump to ",
+              std::to_string(instruction_jump.target)
+            )
+          );
+        }
+        break;
+      }
+
+      case InstructionKind::Split: {
+        const auto& instruction_split(
+          static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+            const InstructionSplit&
+          >(
+            instruction
+          )
+        );
+
+        if (instruction_split.first_target >= program.size()) {
+          throw std::invalid_argument(
+            common::Concat(
+              "Unexpected split & jump beyond the end of the program. Program has ",
+              std::to_string(program.size()),
+              " instruction(s), but the instruction ",
+              std::to_string(i),
+              " wants to split and make the first jump to ",
+              std::to_string(instruction_split.first_target)
+            )
+          );
+        }
+
+        if (instruction_split.second_target >= program.size()) {
+          throw std::invalid_argument(
+            common::Concat(
+              "Unexpected split & jump beyond the end of the program. Program has ",
+              std::to_string(program.size()),
+              " instruction(s), but the instruction ",
+              std::to_string(i),
+              " wants to split and make the second jump to ",
+              std::to_string(instruction_split.second_target)
+            )
+          );
+        }
+
+        break;
+      }
+
+      default:
+        continue;
+    }
+  }
+
+  // NOTE (mristin):
+  // See: https://swtch.com/~rsc/regexp/regexp2.html,
+  // Section "Thompson's Implementation".
+
+  std::unique_ptr<ThreadList> clist(common::make_unique<ThreadList>(program.size()));
+  std::unique_ptr<ThreadList> nlist(common::make_unique<ThreadList>(program.size()));
+
+  clist->Spawn(0);
+
+  for (const wchar_t character : text) {
+    #ifdef DEBUG
+    if (!nlist->Empty()) {
+      throw std::logic_error(
+        "Expected the list of next-to-be-executed threads to be empty, "
+        "but it was not."
+      );
+    }
+    #endif
+
+    while (!clist->Empty()) {
+      const size_t program_counter = clist->Pop();
+
+      #ifdef DEBUG
+      if (program_counter >= program.size()) {
+        throw std::logic_error(
+          common::Concat(
+            "Unexpected program counter beyond the program. The program size was ",
+            std::to_string(program.size()),
+            ", while the program counter of a thread was ",
+            std::to_string(program_counter)
+          )
+        );
+      }
+      #endif
+
+      const Instruction& instruction = *program[program_counter];
+
+      switch (instruction.kind()) {
+        case InstructionKind::Char: {
+          const auto& instruction_char(
+            static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+              const InstructionChar&
+            >(instruction)
+          );
+
+          if (character != instruction_char.character) {
+            // The matching failed for this thread.
+            break;
+          }
+
+          nlist->Spawn(program_counter + 1);
+          break;
+        }
+
+        case InstructionKind::Set: {
+          const auto& instruction_set(
+            static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+              const InstructionSet&
+            >(instruction)
+          );
+
+          if (!CharacterInRanges(instruction_set.ranges, character)) {
+            // The matching failed for this thread.
+            break;
+          }
+
+          nlist->Spawn(program_counter + 1);
+          break;
+        }
+
+        case InstructionKind::NotSet: {
+          const auto& instruction_not_set(
+            static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+              const InstructionNotSet&
+            >(instruction)
+          );
+
+          if (CharacterInRanges(instruction_not_set.ranges, character)) {
+            // The matching failed for this thread.
+            break;
+          }
+
+          nlist->Spawn(program_counter + 1);
+          break;
+        }
+
+        case InstructionKind::Any: {
+          // NOTE (mristin):
+          // We simply proceed to the next instruction at the next character without
+          // any checks.
+          nlist->Spawn(program_counter + 1);
+          break;
+        }
+
+        case InstructionKind::Match:
+          return true;
+
+        case InstructionKind::Jump: {
+          const auto& instruction_jump(
+            static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+              const InstructionJump&
+            >(instruction)
+          );
+
+          clist->Spawn(instruction_jump.target);
+          break;
+        }
+
+        case InstructionKind::Split: {
+          const auto& instruction_split(
+            static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+              const InstructionSplit&
+            >(instruction)
+          );
+
+          clist->Spawn(instruction_split.first_target);
+          clist->Spawn(instruction_split.second_target);
+          break;
+        }
+
+        case InstructionKind::End: {
+          // The matching failed for this thread as we have just consumed
+          // a character.
+          break;
+        }
+
+        default:
+          throw std::logic_error(
+            common::Concat(
+              "Unhandled instruction kind: ",
+              std::to_string(
+                static_cast<std::uint8_t>(instruction.kind())
+              )
+            )
+          );
+      }
+    }
+
+    std::swap(clist, nlist);
+    nlist->Clear();
+  }
+
+  // NOTE (mristin):
+  // We need to process any pending jumps, splits and matches even tough there are
+  // no more characters to consume.
+  while (!clist->Empty()) {
+    const size_t program_counter = clist->Pop();
+
+    #ifdef DEBUG
+    if (program_counter >= program.size()) {
+      throw std::logic_error(
+        common::Concat(
+          "Unexpected program counter beyond the program. The program size was ",
+          std::to_string(program.size()),
+          ", while the program counter of a thread was ",
+          std::to_string(program_counter)
+        )
+      );
+    }
+    #endif
+
+    const Instruction& instruction = *program[program_counter];
+
+    switch (instruction.kind()) {
+      case InstructionKind::Char: { // NOLINT(bugprone-branch-clone)
+        // We reached the end-of-input so there are no characters to be matched.
+        // This thread needs therefore to die.
+        break;
+      }
+
+      case InstructionKind::Set: {
+        // We reached the end-of-input so there are no character sets to be matched.
+        // This thread needs therefore to die.
+        break;
+      }
+
+      case InstructionKind::NotSet: {
+        // We reached the end-of-input so there are no character sets to be matched.
+        // This thread needs therefore to die.
+        break;
+      }
+
+      case InstructionKind::Any: {
+        // We reached the end-of-input so there are no characters to be matched.
+        // This thread needs therefore to die.
+        break;
+      }
+
+      case InstructionKind::Match:
+        return true;
+
+      case InstructionKind::Jump: {
+        const auto& instruction_jump(
+          static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+            const InstructionJump&
+          >(instruction)
+        );
+
+        clist->Spawn(instruction_jump.target);
+        break;
+      }
+
+      case InstructionKind::Split: {
+        const auto& instruction_split(
+          static_cast< // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+            const InstructionSplit&
+          >(instruction)
+        );
+
+        clist->Spawn(instruction_split.first_target);
+        clist->Spawn(instruction_split.second_target);
+        break;
+      }
+
+      case InstructionKind::End: {
+        // We reached the end-of-input so we match and move to the next instruction.
+        clist->Spawn(program_counter + 1);
+        break;
+      }
+
+      default:
+        throw std::logic_error(
+          common::Concat(
+            "Unhandled instruction kind: ",
+            std::to_string(
+              static_cast<std::uint8_t>(instruction.kind())
+            )
+          )
+        );
+    }
+  }
+
+  return false;
+}
+
+}  // namespace revm
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/stringification.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/stringification.cpp
new file mode 100644
index 000000000..14c78c877
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/stringification.cpp
@@ -0,0 +1,375 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/stringification.hpp"
+
+#pragma warning(push, 0)
+#include <unordered_map>
+#pragma warning(pop)
+
+namespace dummy {
+namespace stringification {
+
+const std::unordered_map<
+  std::string,
+  types::ModelType
+> kModelTypeFromStringMap = {
+  {
+    "SomeItem",
+    types::ModelType::kSomeItem
+  },
+  {
+    "SpecialItem",
+    types::ModelType::kSpecialItem
+  },
+  {
+    "Container",
+    types::ModelType::kContainer
+  },
+  {
+    "Wrapper",
+    types::ModelType::kWrapper
+  }
+};
+
+common::optional<types::ModelType> ModelTypeFromString(
+  const std::string& text
+) {
+  const auto it = kModelTypeFromStringMap.find(
+    text
+  );
+  if (it == kModelTypeFromStringMap.end()) {
+    return {};
+  }
+  return it->second;
+}
+
+types::ModelType MustModelTypeFromString(
+  const std::string& text
+) {
+  const auto it = kModelTypeFromStringMap.find(
+    text
+  );
+  if (it == kModelTypeFromStringMap.end()) {
+    throw std::invalid_argument(
+      common::Concat(
+        "Unexpected ModelType literal: ",
+        text
+      )
+    );
+  }
+  return it->second;
+}
+
+std::string to_string(
+  types::ModelType model_type
+) {
+  switch (model_type) {
+    case types::ModelType::kSomeItem:
+    return "SomeItem";
+    case types::ModelType::kSpecialItem:
+    return "SpecialItem";
+    case types::ModelType::kContainer:
+    return "Container";
+    case types::ModelType::kWrapper:
+    return "Wrapper";
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(
+              model_type
+            )
+          )
+        )
+      );
+  }
+}
+
+// The following encoder has been adapted from Jouni Malinen <j@w1.fi> to work with
+// std::string. The original source code is available at:
+// https://web.mit.edu/freebsd/head/contrib/wpa/src/utils/base64.c
+//
+// See also the following StackOverflow question for a benchmark:
+// https://stackoverflow.com/questions/342409/how-do-i-base64-encode-decode-in-c/41094722#41094722
+
+constexpr std::size_t kCharBase64TableLen = 65;
+static const unsigned char kCharBase64Table[kCharBase64TableLen](
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+);
+
+std::string Base64Encode(
+  const std::vector<std::uint8_t>& bytes
+) {
+  // See: https://cplusplus.com/reference/vector/vector/data/.
+  // The data is guaranteed to be a continuous block in memory.
+  const unsigned char* const src(
+    bytes.data()
+  );
+
+  const std::size_t len = bytes.size();
+
+  // 3-byte blocks to 4-byte
+  const std::size_t olen = 4 * ((len + 2) / 3);
+
+  // Integer overflow?
+  if (olen < len) {
+    throw std::invalid_argument(
+      common::Concat(
+        "The calculation of the output length overflowed. "
+        "The length was: ",
+        std::to_string(len),
+        ", but the output length was calculated as: ",
+        std::to_string(olen)
+      )
+    );
+  }
+
+  std::string out_string;
+  out_string.resize(olen);
+
+  unsigned char* out(
+    reinterpret_cast<unsigned char*>(
+      &out_string[0]
+    )
+  );
+
+  const unsigned char* const end = src + len;
+
+  const unsigned char* in = src;
+  unsigned char* pos = out;
+
+  while (end - in >= 3) {
+    *pos++ = kCharBase64Table[in[0] >> 2];
+    *pos++ = kCharBase64Table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
+    *pos++ = kCharBase64Table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
+    *pos++ = kCharBase64Table[in[2] & 0x3f];
+    in += 3;
+  }
+
+  if (end - in) {
+    *pos++ = kCharBase64Table[in[0] >> 2];
+
+    if (end - in == 1) {
+      *pos++ = kCharBase64Table[(in[0] & 0x03) << 4];
+      *pos++ = '=';
+    } else {
+      *pos++ = kCharBase64Table[
+        ((in[0] & 0x03) << 4) | (in[1] >> 4)
+      ];
+      *pos++ = kCharBase64Table[(in[1] & 0x0f) << 2];
+    }
+    *pos++ = '=';
+  }
+
+  return out_string;
+}
+
+// The following decoder is vaguely based on:
+// https://github.com/danguer/blog-examples/blob/master/js/base64-binary.js,
+// https://github.com/niklasvh/base64-arraybuffer/blob/master/src/index.ts and
+// https://github.com/beatgammit/base64-js/blob/master/index.js.
+
+std::vector<std::uint8_t> ConstructBase64Lookup() {
+  std::vector<std::uint8_t> lookup(256, 255);
+  for (std::uint8_t i = 0; i < kCharBase64TableLen; ++i) {
+    lookup.at(kCharBase64Table[i]) = i;
+  }
+  return lookup;
+}
+const std::vector<std::uint8_t> kBase64Lookup = ConstructBase64Lookup();
+
+common::expected<
+  std::vector<std::uint8_t>,
+  std::string
+> Base64Decode(
+  const std::string& text
+) {
+  if (text.empty()) {
+    return std::vector<std::uint8_t>();
+  }
+
+  const std::size_t len = text.size();
+  std::size_t len_wo_pad = len;
+
+  // NOTE (mristin):
+  // Some implementations forget the padding, so we try to be robust and check
+  // for the padding manually.
+  std::size_t bytes_length = (len * 3) / 4;
+  if (text[len - 1] == '=') {
+    bytes_length--;
+    len_wo_pad--;
+
+    if (text[len - 2] == '=') {
+      bytes_length--;
+      len_wo_pad--;
+    }
+  }
+
+  std::vector<std::uint8_t> bytes(bytes_length);
+
+  const std::size_t base64_lookup_len = kBase64Lookup.size();
+
+  std::size_t pointer = 0;
+
+  for (std::size_t i = 0; i < len; i += 4) {
+    // NOTE (mristin):
+    // Admittedly, this is very verbose code, but we want to be efficient, so we
+    // opted for performance over readability here.
+
+    const unsigned char code0 = text[i];
+    if (code0 >= base64_lookup_len) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i),
+        ": ",
+        std::to_string(code0),
+        " (code: ",
+        std::to_string(static_cast<int>(code0)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+    const std::uint8_t encoded0 = kBase64Lookup[code0];
+    if (encoded0 == 255) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i),
+        ": ",
+        std::to_string(code0),
+        " (code: ",
+        std::to_string(static_cast<int>(code0)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+
+    const unsigned char code1 = text[i + 1];
+    if (code1 >= base64_lookup_len) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 1),
+        ": ",
+        std::to_string(code1),
+        " (code: ",
+        std::to_string(static_cast<int>(code1)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+    const std::uint8_t encoded1 = kBase64Lookup[code1];
+    if (encoded1 == 255) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 1),
+        ": ",
+        std::to_string(code1),
+        " (code: ",
+        std::to_string(static_cast<int>(code1)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+
+    // We map padding to 65, which is the value of "A".
+    const unsigned char code2 = i + 2 < len_wo_pad ? text[i + 2] : 65;
+    if (code2 >= base64_lookup_len) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 2),
+        ": ",
+        std::to_string(code2),
+        " (code: ",
+        std::to_string(static_cast<int>(code2)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+    const std::uint8_t encoded2 = kBase64Lookup[code2];
+    if (encoded2 == 255) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 2),
+        ": ",
+        std::to_string(code2),
+        " (code: ",
+        std::to_string(static_cast<int>(code2)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+
+    // We map padding to 65, which is the value of 'A'.
+    const unsigned char code3 = i + 3 < len_wo_pad ? text[i + 3] : 65;
+    if (code3 >= base64_lookup_len) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 3),
+        ": ",
+        std::to_string(code3),
+        " (code: ",
+        std::to_string(static_cast<int>(code3)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+    const std::uint8_t encoded3 = kBase64Lookup[code3];
+    if (encoded3 == 255) {
+      std::string message = common::Concat(
+        "Expected a valid character from base64-encoded string, "
+        "but got at index ",
+        std::to_string(i + 3),
+        ": ",
+        std::to_string(code3),
+        " (code: ",
+        std::to_string(static_cast<int>(code3)),
+        ")"
+      );
+
+      return common::make_unexpected(message);
+    }
+
+    if (pointer >= bytes_length) {
+      break;
+    }
+    bytes[pointer] = (encoded0 << 2) | (encoded1 >> 4);
+    pointer++;
+
+    if (pointer >= bytes_length) {
+      break;
+    }
+    bytes[pointer] = ((encoded1 & 15) << 4) | (encoded2 >> 2);
+    pointer++;
+
+    if (pointer >= bytes_length) {
+      break;
+    }
+    bytes[pointer] = ((encoded2 & 3) << 6) | (encoded3 & 63);
+    pointer++;
+  }
+
+  return bytes;
+}
+
+}  // namespace stringification
+/**@}*/
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/types.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/types.cpp
new file mode 100644
index 000000000..6dac0313f
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/types.cpp
@@ -0,0 +1,375 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/constants.hpp"
+#include "dummy/types.hpp"
+
+namespace dummy {
+namespace types {
+
+// region SomeItem
+
+SomeItem::SomeItem(
+  std::wstring name,
+  common::optional<std::wstring> nickname
+) {
+  name_ = std::move(name);
+
+  nickname_ = std::move(nickname);
+}
+
+ModelType SomeItem::model_type() const {
+  return ModelType::kSomeItem;
+}
+
+const std::wstring& SomeItem::name() const {
+  return name_;
+}
+
+std::wstring& SomeItem::mutable_name() {
+  return name_;
+}
+
+void SomeItem::set_name(
+  std::wstring value
+) {
+  name_ = value;
+}
+
+const common::optional<std::wstring>& SomeItem::nickname() const {
+  return nickname_;
+}
+
+common::optional<std::wstring>& SomeItem::mutable_nickname() {
+  return nickname_;
+}
+
+void SomeItem::set_nickname(
+  common::optional<std::wstring> value
+) {
+  nickname_ = value;
+}
+
+// endregion SomeItem
+
+// region SpecialItem
+
+SpecialItem::SpecialItem(
+  std::wstring name,
+  int64_t level,
+  common::optional<std::wstring> nickname
+) {
+  name_ = std::move(name);
+
+  nickname_ = std::move(nickname);
+
+  level_ = level;
+}
+
+ModelType SpecialItem::model_type() const {
+  return ModelType::kSpecialItem;
+}
+
+const std::wstring& SpecialItem::name() const {
+  return name_;
+}
+
+std::wstring& SpecialItem::mutable_name() {
+  return name_;
+}
+
+void SpecialItem::set_name(
+  std::wstring value
+) {
+  name_ = value;
+}
+
+const common::optional<std::wstring>& SpecialItem::nickname() const {
+  return nickname_;
+}
+
+common::optional<std::wstring>& SpecialItem::mutable_nickname() {
+  return nickname_;
+}
+
+void SpecialItem::set_nickname(
+  common::optional<std::wstring> value
+) {
+  nickname_ = value;
+}
+
+int64_t SpecialItem::level() const {
+  return level_;
+}
+
+int64_t& SpecialItem::mutable_level() {
+  return level_;
+}
+
+void SpecialItem::set_level(
+  int64_t value
+) {
+  level_ = value;
+}
+
+// endregion SpecialItem
+
+// region Container
+
+Container::Container(
+  std::vector<
+    std::shared_ptr<IItem>
+  > items,
+  std::vector<
+    std::shared_ptr<ISomeItem>
+  > some_items,
+  common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  > special_items
+) {
+  items_ = std::move(items);
+
+  some_items_ = std::move(some_items);
+
+  special_items_ = std::move(special_items);
+}
+
+ModelType Container::model_type() const {
+  return ModelType::kContainer;
+}
+
+const std::vector<
+  std::shared_ptr<IItem>
+>& Container::items() const {
+  return items_;
+}
+
+std::vector<
+  std::shared_ptr<IItem>
+>& Container::mutable_items() {
+  return items_;
+}
+
+void Container::set_items(
+  std::vector<
+    std::shared_ptr<IItem>
+  > value
+) {
+  items_ = value;
+}
+
+const std::vector<
+  std::shared_ptr<ISomeItem>
+>& Container::some_items() const {
+  return some_items_;
+}
+
+std::vector<
+  std::shared_ptr<ISomeItem>
+>& Container::mutable_some_items() {
+  return some_items_;
+}
+
+void Container::set_some_items(
+  std::vector<
+    std::shared_ptr<ISomeItem>
+  > value
+) {
+  some_items_ = value;
+}
+
+const common::optional<
+  std::vector<
+    std::shared_ptr<ISpecialItem>
+  >
+>& Container::special_items() const {
+  return special_items_;
+}
+
+common::optional<
+  std::vector<
+    std::shared_ptr<ISpecialItem>
+  >
+>& Container::mutable_special_items() {
+  return special_items_;
+}
+
+void Container::set_special_items(
+  common::optional<
+    std::vector<
+      std::shared_ptr<ISpecialItem>
+    >
+  > value
+) {
+  special_items_ = value;
+}
+
+int64_t Container::CountItems(
+  const std::vector<
+    std::shared_ptr<IItem>
+  >& items
+) const {
+  return items.size();
+}
+
+// endregion Container
+
+// region Wrapper
+
+Wrapper::Wrapper(
+  std::shared_ptr<IContainer> container
+) {
+  container_ = std::move(container);
+}
+
+ModelType Wrapper::model_type() const {
+  return ModelType::kWrapper;
+}
+
+const std::shared_ptr<IContainer>& Wrapper::container() const {
+  return container_;
+}
+
+std::shared_ptr<IContainer>& Wrapper::mutable_container() {
+  return container_;
+}
+
+void Wrapper::set_container(
+  std::shared_ptr<IContainer> value
+) {
+  container_ = value;
+}
+
+// endregion Wrapper
+
+// region Is-a functions
+
+bool IsItem(
+  const IClass& that
+) {
+  switch (that.model_type()) {
+    case ModelType::kSomeItem:
+      return true;
+    case ModelType::kSpecialItem:
+      return true;
+    case ModelType::kContainer:
+      return false;
+    case ModelType::kWrapper:
+      return false;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that.model_type())
+          )
+        )
+      );
+  }
+}
+
+bool IsSomeItem(
+  const IClass& that
+) {
+  switch (that.model_type()) {
+    case ModelType::kSomeItem:
+      return true;
+    case ModelType::kSpecialItem:
+      return true;
+    case ModelType::kContainer:
+      return false;
+    case ModelType::kWrapper:
+      return false;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that.model_type())
+          )
+        )
+      );
+  }
+}
+
+bool IsSpecialItem(
+  const IClass& that
+) {
+  switch (that.model_type()) {
+    case ModelType::kSomeItem:
+      return false;
+    case ModelType::kSpecialItem:
+      return true;
+    case ModelType::kContainer:
+      return false;
+    case ModelType::kWrapper:
+      return false;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that.model_type())
+          )
+        )
+      );
+  }
+}
+
+bool IsContainer(
+  const IClass& that
+) {
+  switch (that.model_type()) {
+    case ModelType::kSomeItem:
+      return false;
+    case ModelType::kSpecialItem:
+      return false;
+    case ModelType::kContainer:
+      return true;
+    case ModelType::kWrapper:
+      return false;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that.model_type())
+          )
+        )
+      );
+  }
+}
+
+bool IsWrapper(
+  const IClass& that
+) {
+  switch (that.model_type()) {
+    case ModelType::kSomeItem:
+      return false;
+    case ModelType::kSpecialItem:
+      return false;
+    case ModelType::kContainer:
+      return false;
+    case ModelType::kWrapper:
+      return true;
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that.model_type())
+          )
+        )
+      );
+  }
+}
+
+// endregion Is-a functions
+
+}  // namespace types
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/verification.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/verification.cpp
new file mode 100644
index 000000000..ea55dcf18
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/verification.cpp
@@ -0,0 +1,1246 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/constants.hpp"
+#include "dummy/pattern.hpp"
+#include "dummy/revm.hpp"
+#include "dummy/stringification.hpp"
+#include "dummy/verification.hpp"
+
+#pragma warning(push, 0)
+#include <map>
+#include <set>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+namespace verification {
+
+// region struct Error
+
+Error::Error(
+  std::wstring a_cause
+) :
+  cause(std::move(a_cause)) {
+  // Intentionally empty.
+}
+
+Error::Error(
+  std::wstring a_cause,
+  iteration::Path a_path
+) :
+  cause(std::move(a_cause)),
+  path(std::move(a_path)) {
+  // Intentionally empty.
+}
+
+// endregion struct Error
+
+// region Verification functions
+
+bool ContainsSpecialItem(
+  const std::shared_ptr<types::ISpecialItem>& special_item,
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& items
+) {
+  return (
+    common::Contains(
+      items,
+      special_item
+    )
+  );
+}
+
+bool ContainerNamesAreUnique(
+  const std::shared_ptr<types::IContainer>& container
+) {
+  const auto& some_items = container->some_items();
+  const std::vector<std::shared_ptr<types::ISomeItem> >& all_some_items = container->some_items();
+  return (
+    (
+      NamesAreUnique(
+        some_items
+      )
+      && NamesAreUnique(
+        all_some_items
+      )
+      && OptionalNamesAreUnique(
+        common::make_optional(
+          all_some_items
+        )
+      )
+    )
+  );
+}
+
+bool LevelsArePositive(
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& items
+) {
+  return (
+    common::All(
+      [&](const std::shared_ptr<types::ISpecialItem>& item) -> bool {
+        return item->level() > 0;
+      },
+      items
+    )
+  );
+}
+
+// endregion Verification functions
+
+namespace {
+
+/**
+ * \brief Enumerate the shapes of the values that we verify.
+ *
+ * A shape tells which checks apply to a value, see \ref ChecksOf.
+ */
+enum class Shape : std::uint32_t {
+  kContainer = 0,
+  kWrapper = 1
+};  // enum class Shape
+
+/**
+ * \brief Represent a single check of a value.
+ *
+ * The checks of a shape are listed in \ref ChecksOf.
+ */
+struct Check {
+  /**
+   * Check that the invariant holds for the value
+   */
+  bool (*holds)(const void* value);
+
+  /**
+   * Human-readable description of the invariant, reported if it does not hold
+   */
+  const wchar_t* message;
+};  // struct Check
+
+// region Checks
+
+bool Container_0(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return !(that->special_items().has_value())
+  || common::All(
+    [&](const std::shared_ptr<types::ISpecialItem>& special_item) -> bool {
+      return verification::ContainsSpecialItem(
+        special_item,
+        (*(that->special_items()))
+      );
+    },
+    (*(that->special_items()))
+  );
+}
+
+bool Container_1(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return (
+    that->some_items().size() == 0
+    || verification::ItemsOverlap(
+      that->items(),
+      that->some_items()
+    )
+  );
+}
+
+bool Container_2(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return common::All(
+    [&](const std::shared_ptr<types::ISomeItem>& some_item) -> bool {
+      return verification::ContainsSomeItem(
+        some_item,
+        that->items()
+      );
+    },
+    that->some_items()
+  );
+}
+
+bool Container_3(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::AliasedNamesAreUnique(
+    that->some_items(),
+    that->special_items()
+  );
+}
+
+bool Container_4(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::NamesAreDisjoint(
+    that->items(),
+    that->some_items(),
+    L"x"
+  );
+}
+
+bool Container_5(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return !verification::SomeSpecialItemHasLevel(
+    that->items()
+  )
+  || verification::LastIsSpecial(
+    that->items()
+  );
+}
+
+bool Container_6(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::LevelsOfSpecialItemsArePositive(
+    that->items()
+  );
+}
+
+bool Container_7(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::NicknamesAreUnique(
+    that->some_items()
+  );
+}
+
+bool Container_8(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return that->CountItems(
+    that->items()
+  ) == static_cast<int64_t>(that->items().size());
+}
+
+bool Container_9(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::OptionalNamesAreUnique(
+    that->special_items()
+  );
+}
+
+bool Container_10(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return !(that->special_items().has_value())
+  || verification::FirstIsSpecial(
+    (*(that->special_items()))
+  );
+}
+
+bool Container_11(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return !(that->special_items().has_value())
+  || verification::LevelsArePositive(
+    (*(that->special_items()))
+  );
+}
+
+bool Container_12(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return !verification::SomeSpecialItemHasLevel(
+    that->items()
+  )
+  || verification::FirstIsSpecial(
+    that->items()
+  );
+}
+
+bool Container_13(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::NamesAreNonEmpty(
+    that->some_items()
+  );
+}
+
+bool Container_14(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::SomeNamesAreUnique(
+    that->some_items(),
+    that->special_items()
+  );
+}
+
+bool Container_15(
+  const void* value
+) {
+  const types::IContainer* that = (
+    static_cast<const types::IContainer*>(value)
+  );
+  return verification::NamesAreUnique(
+    that->items()
+  );
+}
+
+bool Wrapper_0(
+  const void* value
+) {
+  const types::IWrapper* that = (
+    static_cast<const types::IWrapper*>(value)
+  );
+  return verification::ContainerNamesAreUnique(
+    that->container()
+  );
+}
+
+/**
+ * Give out the checks of the values of the \p shape.
+ */
+const std::vector<Check>& ChecksOf(Shape shape) {
+  switch (shape) {
+    case Shape::kContainer: {
+      static const std::vector<Check> checks = {
+        {
+          &Container_0,
+          L"Each special item must be among the special items."
+        },
+        {
+          &Container_1,
+          L"If there are some items, they must overlap with the items."
+        },
+        {
+          &Container_2,
+          L"Some items must be among the items."
+        },
+        {
+          &Container_3,
+          L"Names of some items and of special items must be unique "
+          L"through aliases."
+        },
+        {
+          &Container_4,
+          L"Names of the items and of some items must be disjoint."
+        },
+        {
+          &Container_5,
+          L"If there is a special item with level, the last item must "
+          L"be special."
+        },
+        {
+          &Container_6,
+          L"Levels of the special items among the items must be "
+          L"positive."
+        },
+        {
+          &Container_7,
+          L"Nicknames of some items must be unique."
+        },
+        {
+          &Container_8,
+          L"Count of the items must match the number of the items."
+        },
+        {
+          &Container_9,
+          L"Names of the special items must be unique."
+        },
+        {
+          &Container_10,
+          L"The first special item must be special."
+        },
+        {
+          &Container_11,
+          L"Levels of the special items must be positive."
+        },
+        {
+          &Container_12,
+          L"If there is a special item with level, the first item must "
+          L"be special."
+        },
+        {
+          &Container_13,
+          L"Names of some items must be non-empty."
+        },
+        {
+          &Container_14,
+          L"Names of some items and of special items must be unique."
+        },
+        {
+          &Container_15,
+          L"Names of the items must be unique."
+        }
+      };
+      return checks;
+    }
+    case Shape::kWrapper: {
+      static const std::vector<Check> checks = {
+        {
+          &Wrapper_0,
+          L"Names of some items of the container must be unique."
+        }
+      };
+      return checks;
+    }
+    default:
+      throw std::logic_error(
+        common::Concat(
+          "Unexpected shape: ",
+          std::to_string(static_cast<std::uint32_t>(shape))
+        )
+      );
+  }
+}
+
+// endregion Checks
+
+/**
+ * \brief Create the nested verification of the \p value, if its \p shape has one.
+ *
+ * \return nullptr if the shape has no nested verification
+ */
+std::unique_ptr<impl::IVerificator> NewNestedVerificator(
+  Shape,
+  const void*
+) {
+  // NOTE (mristin):
+  // The meta-model uses no JSON-able values, so no value needs a nested
+  // verification.
+  return nullptr;
+}
+
+// region Iteration over the values
+
+/**
+ * \brief Iterate lazily over the values to be verified.
+ *
+ * Every value comes with its \ref Shape, which tells which checks apply to it.
+ *
+ * We build no paths while iterating. The path to the current value is built only
+ * when an error has been found, see \ref AppendToPath.
+ *
+ * The iterators are combined out of the combinators below. They follow three rules
+ * so that we never build the iterators over the whole model up front:
+ * 1. \ref ChainIterator starts a child only once the previous child is done.
+ * 2. \ref DispatchingIterator dispatches on the instance only in \ref Start.
+ * 3. \ref EachIterator builds the iterator over an item only once the iteration
+ *    reaches the item.
+ *
+ * Under these rules, every combinator is cheap to construct eagerly.
+ */
+class IIterator {
+ public:
+  /**
+   * Position at the first value, or become done if there are no values.
+   */
+  virtual void Start() = 0;
+
+  /**
+   * Move to the next value, or become done if there are no more values.
+   */
+  virtual void Next() = 0;
+
+  virtual bool Done() const = 0;
+
+  /**
+   * \brief Point to the current value.
+   *
+   * The pointer is valid only until the next call to \ref Next.
+   */
+  virtual const void* Value() const = 0;
+
+  virtual Shape ShapeOf() const = 0;
+
+  /**
+   * \brief Append the segments leading to the current value to the \p path.
+   *
+   * Only called when an error is found, so the iteration itself builds no paths.
+   */
+  virtual void AppendToPath(iteration::Path& path) const = 0;
+
+  virtual std::unique_ptr<IIterator> Clone() const = 0;
+
+  virtual ~IIterator() = default;
+};  // class IIterator
+
+/**
+ * Iterate over no values at all.
+ */
+class EmptyIterator : public IIterator {
+ public:
+  void Start() override {
+    // Intentionally empty.
+  }
+
+  void Next() override {
+    throw std::logic_error(
+      "You want to move an EmptyIterator, but it is always done."
+    );
+  }
+
+  bool Done() const override {
+    return true;
+  }
+
+  const void* Value() const override {
+    throw std::logic_error(
+      "You want to get a value from an EmptyIterator, but it is always done."
+    );
+  }
+
+  Shape ShapeOf() const override {
+    throw std::logic_error(
+      "You want to get a shape from an EmptyIterator, but it is always done."
+    );
+  }
+
+  void AppendToPath(iteration::Path&) const override {
+    throw std::logic_error(
+      "You want to append the path of an EmptyIterator, but it is always done."
+    );
+  }
+
+  std::unique_ptr<IIterator> Clone() const override {
+    return common::make_unique<EmptyIterator>(*this);
+  }
+};  // class EmptyIterator
+
+std::unique_ptr<IIterator> Empty() {
+  return common::make_unique<EmptyIterator>();
+}
+
+/**
+ * Iterate over a single value which lives in the model.
+ */
+class OneIterator : public IIterator {
+ public:
+  OneIterator(
+    const void* value,
+    Shape shape
+  ) :
+    value_(value),
+    shape_(shape),
+    done_(true) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    done_ = false;
+  }
+
+  void Next() override {
+    done_ = true;
+  }
+
+  bool Done() const override {
+    return done_;
+  }
+
+  const void* Value() const override {
+    return value_;
+  }
+
+  Shape ShapeOf() const override {
+    return shape_;
+  }
+
+  void AppendToPath(iteration::Path&) const override {
+    // Intentionally empty, as the value itself is the end of the path.
+  }
+
+  std::unique_ptr<IIterator> Clone() const override {
+    return common::make_unique<OneIterator>(*this);
+  }
+
+ private:
+  const void* value_;
+  Shape shape_;
+  bool done_;
+};  // class OneIterator
+
+std::unique_ptr<IIterator> One(
+  const void* value,
+  Shape shape
+) {
+  return common::make_unique<OneIterator>(value, shape);
+}
+
+/**
+ * \brief Iterate over the values of the children, one child after another.
+ *
+ * A child is started only once the previous child is done.
+ */
+class ChainIterator : public IIterator {
+ public:
+  explicit ChainIterator(
+    std::vector<std::unique_ptr<IIterator> > children
+  ) :
+    children_(std::move(children)),
+    active_(0) {
+    // Intentionally empty.
+  }
+
+  ChainIterator(const ChainIterator& other) :
+    active_(other.active_) {
+    children_.reserve(other.children_.size());
+    for (const std::unique_ptr<IIterator>& child : other.children_) {
+      children_.emplace_back(child->Clone());
+    }
+  }
+
+  void Start() override {
+    active_ = 0;
+    if (!children_.empty()) {
+      children_[0]->Start();
+    }
+    SkipDoneChildren();
+  }
+
+  void Next() override {
+    children_[active_]->Next();
+    SkipDoneChildren();
+  }
+
+  bool Done() const override {
+    return active_ >= children_.size();
+  }
+
+  const void* Value() const override {
+    return children_[active_]->Value();
+  }
+
+  Shape ShapeOf() const override {
+    return children_[active_]->ShapeOf();
+  }
+
+  void AppendToPath(iteration::Path& path) const override {
+    children_[active_]->AppendToPath(path);
+  }
+
+  std::unique_ptr<IIterator> Clone() const override {
+    return common::make_unique<ChainIterator>(*this);
+  }
+
+ private:
+  std::vector<std::unique_ptr<IIterator> > children_;
+
+  /**
+   * Index of the child we currently iterate over
+   */
+  std::size_t active_;
+
+  /**
+   * Move on to the next children, and start them, until one is not done.
+   */
+  void SkipDoneChildren() {
+    while (active_ < children_.size() && children_[active_]->Done()) {
+      ++active_;
+      if (active_ < children_.size()) {
+        children_[active_]->Start();
+      }
+    }
+  }
+};  // class ChainIterator
+
+void CollectChildren(
+  std::vector<std::unique_ptr<IIterator> >&
+) {
+  // Intentionally empty, as there are no more children to collect.
+}
+
+template<typename... Rest>
+void CollectChildren(
+  std::vector<std::unique_ptr<IIterator> >& children,
+  std::unique_ptr<IIterator> first,
+  Rest... rest
+) {
+  children.emplace_back(std::move(first));
+  CollectChildren(children, std::move(rest)...);
+}
+
+// NOTE (mristin):
+// We can not use an initializer list here, as we can not move the unique pointers
+// out of it.
+template<typename... Children>
+std::unique_ptr<IIterator> Chain(
+  Children... children
+) {
+  std::vector<std::unique_ptr<IIterator> > collected;
+  collected.reserve(sizeof...(Children));
+  CollectChildren(collected, std::move(children)...);
+
+  return common::make_unique<ChainIterator>(std::move(collected));
+}
+
+/**
+ * Iterate over the values of the \p child, which lives in a property.
+ */
+class InPropertyIterator : public IIterator {
+ public:
+  InPropertyIterator(
+    iteration::Property property,
+    std::unique_ptr<IIterator> child
+  ) :
+    property_(property),
+    child_(std::move(child)) {
+    // Intentionally empty.
+  }
+
+  InPropertyIterator(const InPropertyIterator& other) :
+    property_(other.property_),
+    child_(other.child_->Clone()) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    child_->Start();
+  }
+
+  void Next() override {
+    child_->Next();
+  }
+
+  bool Done() const override {
+    return child_->Done();
+  }
+
+  const void* Value() const override {
+    return child_->Value();
+  }
+
+  Shape ShapeOf() const override {
+    return child_->ShapeOf();
+  }
+
+  void AppendToPath(iteration::Path& path) const override {
+    path.segments.emplace_back(
+      common::make_unique<iteration::PropertySegment>(property_)
+    );
+    child_->AppendToPath(path);
+  }
+
+  std::unique_ptr<IIterator> Clone() const override {
+    return common::make_unique<InPropertyIterator>(*this);
+  }
+
+ private:
+  iteration::Property property_;
+  std::unique_ptr<IIterator> child_;
+};  // class InPropertyIterator
+
+std::unique_ptr<IIterator> InProperty(
+  iteration::Property property,
+  std::unique_ptr<IIterator> child
+) {
+  return common::make_unique<InPropertyIterator>(property, std::move(child));
+}
+
+/**
+ * \brief Iterate over the values of an instance, dispatched on its runtime type.
+ *
+ * Defined below, once all the classes have been covered.
+ */
+std::unique_ptr<IIterator> DispatchOnModelType(
+  const types::IClass& instance,
+  bool recursive
+);
+
+/**
+ * \brief Iterate recursively over the values of an instance referenced from
+ * another instance.
+ *
+ * We dispatch on the runtime type of the instance only in \ref Start so that
+ * we descend into the instance only once the iteration reaches it.
+ */
+class DispatchingIterator : public IIterator {
+ public:
+  explicit DispatchingIterator(
+    const types::IClass* instance
+  ) :
+    instance_(instance) {
+    // Intentionally empty.
+  }
+
+  DispatchingIterator(const DispatchingIterator& other) :
+    instance_(other.instance_),
+    child_(other.child_ == nullptr ? nullptr : other.child_->Clone()) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    child_ = DispatchOnModelType(*instance_, true);
+    child_->Start();
+  }
+
+  void Next() override {
+    child_->Next();
+  }
+
+  bool Done() const override {
+    return child_->Done();
+  }
+
+  const void* Value() const override {
+    return child_->Value();
+  }
+
+  Shape ShapeOf() const override {
+    return child_->ShapeOf();
+  }
+
+  void AppendToPath(iteration::Path& path) const override {
+    child_->AppendToPath(path);
+  }
+
+  std::unique_ptr<IIterator> Clone() const override {
+    return common::make_unique<DispatchingIterator>(*this);
+  }
+
+ private:
+  const types::IClass* instance_;
+  std::unique_ptr<IIterator> child_;
+};  // class DispatchingIterator
+
+std::unique_ptr<IIterator> Over(
+  const types::IClass& instance,
+  bool recursive
+) {
+  if (!recursive) {
+    // NOTE (mristin):
+    // In the non-recursive mode, we verify only the instance itself, but not
+    // the instances that it references.
+    return Empty();
+  }
+
+  return common::make_unique<DispatchingIterator>(&instance);
+}
+
+template<typename T>
+std::unique_ptr<IIterator> ThroughPointer(
+  const std::shared_ptr<T>& instance,
+  bool recursive
+) {
+  return Over(*instance, recursive);
+}
+
+std::unique_ptr<IIterator> Over_Container(
+  const types::IContainer& that,
+  bool
+) {
+  return One(&that, Shape::kContainer);
+}
+
+std::unique_ptr<IIterator> Over_Wrapper(
+  const types::IWrapper& that,
+  bool recursive
+) {
+  return Chain(
+    One(&that, Shape::kWrapper),
+    InProperty(
+      iteration::Property::kContainer,
+      Over(*that.container(), recursive)
+    )
+  );
+}
+
+/**
+ * Iterate over the values of the \p instance, dispatched on its runtime type.
+ */
+std::unique_ptr<IIterator> DispatchOnModelType(
+  const types::IClass& instance,
+  bool recursive
+) {
+  switch (instance.model_type()) {
+    case types::ModelType::kContainer:
+      return Over_Container(
+        dynamic_cast<const types::IContainer&>(instance),
+        recursive
+      );
+    case types::ModelType::kWrapper:
+      return Over_Wrapper(
+        dynamic_cast<const types::IWrapper&>(instance),
+        recursive
+      );
+    default:
+      // NOTE (mristin):
+      // The instances of the other classes have nothing to verify.
+      return Empty();
+  }
+}
+
+// endregion Iteration over the values
+
+// region Iteration over the errors
+
+/**
+ * \brief Iterate over the errors of the values, one error at a time.
+ *
+ * For every value, we first run the checks of its shape, each reporting at most
+ * one error. Then we run the nested verification of the value, if its shape has
+ * one, which can report many errors, see \ref NewNestedVerificator.
+ *
+ * We do only the work needed to find the next error, and build the path to
+ * the erroneous value only once an error has been found.
+ */
+class ErrorIterator : public impl::IVerificator {
+ public:
+  explicit ErrorIterator(
+    std::unique_ptr<IIterator> values
+  ) :
+    values_(std::move(values)),
+    check_(0),
+    nested_started_(false),
+    index_(-1) {
+    // Intentionally empty.
+  }
+
+  ErrorIterator(const ErrorIterator& other) :
+    values_(other.values_->Clone()),
+    check_(other.check_),
+    nested_started_(other.nested_started_),
+    nested_(other.nested_ == nullptr ? nullptr : other.nested_->Clone()),
+    error_(other.error_),
+    index_(other.index_) {
+    // Intentionally empty.
+  }
+
+  void Start() override {
+    values_->Start();
+    check_ = 0;
+    nested_started_ = false;
+    nested_ = nullptr;
+    index_ = -1;
+
+    Advance();
+  }
+
+  void Next() override {
+    #ifdef DEBUG
+    if (Done()) {
+      throw std::logic_error(
+        "You want to move an ErrorIterator, but it was done."
+      );
+    }
+    #endif
+
+    Advance();
+  }
+
+  bool Done() const override {
+    return values_->Done();
+  }
+
+  const Error& Get() const override {
+    #ifdef DEBUG
+    if (Done()) {
+      throw std::logic_error(
+        "You want to get from an ErrorIterator, but it was done."
+      );
+    }
+    #endif
+
+    return *error_;
+  }
+
+  Error& GetMutable() override {
+    #ifdef DEBUG
+    if (Done()) {
+      throw std::logic_error(
+        "You want to get mutable from an ErrorIterator, but it was done."
+      );
+    }
+    #endif
+
+    return *error_;
+  }
+
+  long Index() const override {
+    return index_;
+  }
+
+  std::unique_ptr<impl::IVerificator> Clone() const override {
+    return common::make_unique<ErrorIterator>(*this);
+  }
+
+ private:
+  std::unique_ptr<IIterator> values_;
+
+  /**
+   * Index of the next check to run on the current value
+   */
+  std::size_t check_;
+
+  /**
+   * Set if we already started the nested verification of the current value
+   */
+  bool nested_started_;
+
+  /**
+   * Nested verification of the current value, if its shape has one
+   */
+  std::unique_ptr<impl::IVerificator> nested_;
+
+  common::optional<Error> error_;
+
+  /**
+   * Index of the current error, -1 if done
+   */
+  long index_;
+
+  /**
+   * Move on to the next error, or become done if there are no more errors.
+   */
+  void Advance() {
+    while (!values_->Done()) {
+      const void* value = values_->Value();
+      const Shape shape = values_->ShapeOf();
+
+      const std::vector<Check>& checks = ChecksOf(shape);
+      while (check_ < checks.size()) {
+        const Check& check = checks[check_];
+        ++check_;
+
+        if (!check.holds(value)) {
+          error_ = Error(check.message);
+          values_->AppendToPath(error_->path);
+          ++index_;
+          return;
+        }
+      }
+
+      // NOTE (mristin):
+      // All the checks of the value have been run. We now either start the nested
+      // verification of the value, or resume it where we stopped at its last error.
+      if (!nested_started_) {
+        nested_started_ = true;
+        nested_ = NewNestedVerificator(shape, value);
+        if (nested_ != nullptr) {
+          nested_->Start();
+        }
+      } else if (nested_ != nullptr) {
+        nested_->Next();
+      }
+
+      if (nested_ != nullptr && !nested_->Done()) {
+        // NOTE (mristin):
+        // The path of the nested error is relative to the value, so we prefix it
+        // with the path to the value. We take over the data members of the nested
+        // error to avoid a costly copy, as we move the nested verification on
+        // before we look at its error again.
+        Error& nested_error = nested_->GetMutable();
+
+        error_ = Error(std::move(nested_error.cause));
+        values_->AppendToPath(error_->path);
+        for (
+          std::unique_ptr<iteration::ISegment>& segment
+          : nested_error.path.segments
+        ) {
+          error_->path.segments.emplace_back(std::move(segment));
+        }
+
+        ++index_;
+        return;
+      }
+
+      values_->Next();
+      check_ = 0;
+      nested_started_ = false;
+      nested_ = nullptr;
+    }
+
+    error_ = common::nullopt;
+    index_ = -1;
+  }
+};  // class ErrorIterator
+
+/**
+ * Start iterating over the errors of the \p values.
+ */
+Iterator IterateErrors(
+  std::unique_ptr<IIterator> values
+) {
+  std::unique_ptr<impl::IVerificator> verificator(
+    common::make_unique<ErrorIterator>(std::move(values))
+  );
+  verificator->Start();
+
+  return Iterator(std::move(verificator));
+}
+
+/**
+ * Give out the iterator past the last error, shared by all the verifications.
+ */
+const Iterator& PastLastError() {
+  static const Iterator iterator(IterateErrors(Empty()));
+  return iterator;
+}
+
+// endregion Iteration over the errors
+
+}  // namespace
+
+// region NonRecursiveVerification
+
+NonRecursiveVerification::NonRecursiveVerification(
+  const std::shared_ptr<types::IClass>& instance
+) : instance_(instance) {
+  // Intentionally empty.
+}
+
+Iterator NonRecursiveVerification::begin() const {
+  return IterateErrors(DispatchOnModelType(*instance_, false));
+}
+
+const Iterator& NonRecursiveVerification::end() const {
+  return PastLastError();
+}
+
+// endregion NonRecursiveVerification
+
+// region RecursiveVerification
+
+RecursiveVerification::RecursiveVerification(
+  const std::shared_ptr<types::IClass>& instance
+) : instance_(instance) {
+  // Intentionally empty.
+}
+
+Iterator RecursiveVerification::begin() const {
+  return IterateErrors(DispatchOnModelType(*instance_, true));
+}
+
+const Iterator& RecursiveVerification::end() const {
+  return PastLastError();
+}
+
+// endregion RecursiveVerification
+
+// region struct Iterator
+
+Iterator::Iterator(
+  const Iterator& other
+) :
+  verificator_(other.verificator_->Clone()) {
+  // Intentionally empty.
+}
+
+Iterator::Iterator(
+  Iterator&& other
+) :
+  verificator_(std::move(other.verificator_)) {
+  // Intentionally empty.
+}
+
+Iterator& Iterator::operator=(const Iterator& other) {
+  return *this = Iterator(other);
+}
+
+Iterator& Iterator::operator=(Iterator&& other) {
+  if (this != &other) {
+    verificator_ = std::move(other.verificator_);
+  }
+
+  return *this;
+}
+
+const Error& Iterator::operator*() const {
+  if (verificator_->Done()) {
+    throw std::logic_error(
+      "You want to de-reference from a completed iterator "
+      "over verification errors."
+    );
+  }
+
+  return verificator_->Get();
+}
+
+const Error* Iterator::operator->() const {
+  if (verificator_->Done()) {
+    throw std::logic_error(
+      "You want to de-reference from a completed iterator "
+      "over verification errors."
+    );
+  }
+
+  return &(verificator_->Get());
+}
+
+// Prefix increment
+Iterator& Iterator::operator++() {
+  if (verificator_->Done()) {
+    throw std::logic_error(
+      "You want to move a completed iterator "
+      "over verification errors."
+    );
+  }
+
+  verificator_->Next();
+  return *this;
+}
+
+// Postfix increment
+Iterator Iterator::operator++(int) {
+  Iterator result(*this);
+  ++(*this);
+  return result;
+}
+
+bool operator==(const Iterator& a, const Iterator& b) {
+  return a.verificator_->Index() == b.verificator_->Index();
+}
+
+bool operator!=(const Iterator& a, const Iterator& b) {
+  return a.verificator_->Index() != b.verificator_->Index();
+}
+
+// endregion struct Iterator
+
+}  // namespace verification
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/visitation.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/visitation.cpp
new file mode 100644
index 000000000..3735f83cf
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/visitation.cpp
@@ -0,0 +1,186 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/types.hpp"
+#include "dummy/stringification.hpp"
+#include "dummy/visitation.hpp"
+
+#pragma warning(push, 0)
+#include <sstream>
+#pragma warning(pop)
+
+namespace dummy {
+namespace visitation {
+
+// region AbstractVisitor
+
+void AbstractVisitor::Visit(
+  const std::shared_ptr<types::IClass>& that
+) {
+  // NOTE (mristin):
+  // We have to dynamically cast the pointers due to the virtual multiple
+  // inheritance, and also because we used shared pointers for references.
+  // If we used constant references instead of shared pointers, we could use
+  // a pattern such as double dispatch. However, this has the limitation that
+  // it would prevent us from collecting the instances in the visitor, such that
+  // they outlive the original structures.
+
+  switch (that->model_type()) {
+    case types::ModelType::kSomeItem:
+      VisitSomeItem(
+        std::dynamic_pointer_cast<
+          types::ISomeItem
+        >(that)
+      );
+      break;
+    case types::ModelType::kSpecialItem:
+      VisitSpecialItem(
+        std::dynamic_pointer_cast<
+          types::ISpecialItem
+        >(that)
+      );
+      break;
+    case types::ModelType::kContainer:
+      VisitContainer(
+        std::dynamic_pointer_cast<
+          types::IContainer
+        >(that)
+      );
+      break;
+    case types::ModelType::kWrapper:
+      VisitWrapper(
+        std::dynamic_pointer_cast<
+          types::IWrapper
+        >(that)
+      );
+      break;
+    default:
+      throw std::logic_error(
+        common::Concat(
+          "Unexpected model type: ",
+          std::to_string(
+            static_cast<std::uint32_t>(that->model_type())
+          )
+        )
+      );
+  }
+}
+
+// endregion
+
+namespace {
+
+// region Pass-through over the containers
+
+/**
+ * Pass the \p visitor through the instances held by \p that.
+ */
+void PassThrough_listOf_Item(
+  IVisitor* visitor,
+  const std::vector<
+    std::shared_ptr<types::IItem>
+  >& that
+) {
+  for (
+    const std::shared_ptr<types::IItem>& item :
+    that
+  ) {
+    visitor->Visit(item);
+  }
+}
+
+/**
+ * Pass the \p visitor through the instances held by \p that.
+ */
+void PassThrough_listOf_SomeItem(
+  IVisitor* visitor,
+  const std::vector<
+    std::shared_ptr<types::ISomeItem>
+  >& that
+) {
+  for (
+    const std::shared_ptr<types::ISomeItem>& item :
+    that
+  ) {
+    visitor->Visit(item);
+  }
+}
+
+/**
+ * Pass the \p visitor through the instances held by \p that.
+ */
+void PassThrough_listOf_SpecialItem(
+  IVisitor* visitor,
+  const std::vector<
+    std::shared_ptr<types::ISpecialItem>
+  >& that
+) {
+  for (
+    const std::shared_ptr<types::ISpecialItem>& item :
+    that
+  ) {
+    visitor->Visit(item);
+  }
+}
+
+// endregion Pass-through over the containers
+
+}  // namespace
+
+// region PassThroughVisitor
+
+void PassThroughVisitor::VisitSomeItem(
+  const std::shared_ptr<types::ISomeItem>&
+) {
+  // No properties to be passed through.
+}
+
+void PassThroughVisitor::VisitSpecialItem(
+  const std::shared_ptr<types::ISpecialItem>&
+) {
+  // No properties to be passed through.
+}
+
+void PassThroughVisitor::VisitContainer(
+  const std::shared_ptr<types::IContainer>& that
+) {
+  // mutable_items
+  PassThrough_listOf_Item(this, that->mutable_items());
+
+  // mutable_some_items
+  PassThrough_listOf_SomeItem(
+    this,
+    that->mutable_some_items()
+  );
+
+  // region mutable_special_items
+  const common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  >& maybe_special_items(
+    that->mutable_special_items()
+  );
+  if (maybe_special_items.has_value()) {
+    PassThrough_listOf_SpecialItem(
+      this,
+      maybe_special_items.value()
+    );
+  }
+  // endregion
+}
+
+void PassThroughVisitor::VisitWrapper(
+  const std::shared_ptr<types::IWrapper>& that
+) {
+  // mutable_container
+  this->Visit(that->mutable_container());
+}
+
+// endregion
+
+}  // namespace visitation
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/wstringification.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/wstringification.cpp
new file mode 100644
index 000000000..eef0b37f5
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/wstringification.cpp
@@ -0,0 +1,94 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/wstringification.hpp"
+
+#pragma warning(push, 0)
+#include <unordered_map>
+#pragma warning(pop)
+
+namespace dummy {
+namespace wstringification {
+
+const std::unordered_map<
+  std::wstring,
+  types::ModelType
+> kModelTypeFromWstringMap = {
+  {
+    L"SomeItem",
+    types::ModelType::kSomeItem
+  },
+  {
+    L"SpecialItem",
+    types::ModelType::kSpecialItem
+  },
+  {
+    L"Container",
+    types::ModelType::kContainer
+  },
+  {
+    L"Wrapper",
+    types::ModelType::kWrapper
+  }
+};
+
+common::optional<types::ModelType> ModelTypeFromWstring(
+  const std::wstring& text
+) {
+  const auto it = kModelTypeFromWstringMap.find(
+    text
+  );
+  if (it == kModelTypeFromWstringMap.end()) {
+    return {};
+  }
+  return it->second;
+}
+
+types::ModelType MustModelTypeFromWstring(
+  const std::wstring& text
+) {
+  const auto it = kModelTypeFromWstringMap.find(
+    text
+  );
+  if (it == kModelTypeFromWstringMap.end()) {
+    throw std::invalid_argument(
+      common::WstringToUtf8(
+        common::Concat(
+          L"Unexpected ModelType literal: ",
+          text
+        )
+      )
+    );
+  }
+  return it->second;
+}
+
+std::wstring to_wstring(
+  types::ModelType model_type
+) {
+  switch (model_type) {
+    case types::ModelType::kSomeItem:
+    return L"SomeItem";
+    case types::ModelType::kSpecialItem:
+    return L"SpecialItem";
+    case types::ModelType::kContainer:
+    return L"Container";
+    case types::ModelType::kWrapper:
+    return L"Wrapper";
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected ModelType literal: ",
+          std::to_string(
+            static_cast<std::uint32_t>(model_type)
+          )
+        )
+      );
+  }
+}
+
+}  // namespace wstringification
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.cpp
new file mode 100644
index 000000000..76d2b8e59
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.cpp
@@ -0,0 +1,1624 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "xml_common.hpp"
+
+#include "dummy/stringification.hpp"
+
+#pragma warning(push, 0)
+#include <expat.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstdint>
+#include <iomanip>
+#include <istream>
+#include <limits>
+#include <locale>
+#include <ostream>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+#include <vector>
+#pragma warning(pop)
+
+static_assert(
+  !std::is_same<XML_Char, wchar_t>::value,
+  "Expected Expat to be compiled with UTF-8 support, i.e., that character is "
+  "stored as char internally, "
+  "but Expat was compiled to store characters internally as UTF-16."
+);
+
+static_assert(
+  std::is_same<XML_Char, char>::value,
+  "Expected Expat to be compiled with UTF-8 support, i.e., that "
+  "character is stored as char internally, "
+  "but it was not."
+);
+
+namespace dummy {
+namespace xml_common {
+
+const char* const kNamespace = "https://dummy.com";
+
+// region Node kind
+
+const std::unordered_map<
+  NodeKind,
+  std::string
+> kNodeKindToHumanReadableString = {
+  {NodeKind::Bof, "a beginning-of-input"},
+  {NodeKind::Start, "a start element"},
+  {NodeKind::Stop, "a stop element"},
+  {NodeKind::Text, "a text"},
+  {NodeKind::Eof, "an end-of-input"},
+  {NodeKind::Error, "an error"},
+  {NodeKind::StartInNoNamespace, "a start element in no namespace"},
+  {NodeKind::StopInNoNamespace, "a stop element in no namespace"},
+};
+
+const std::string& NodeKindToHumanReadableString(NodeKind kind) {
+  auto it = kNodeKindToHumanReadableString.find(kind);
+  if (it == kNodeKindToHumanReadableString.end()) {
+    throw std::invalid_argument(
+      common::Concat(
+        "Unexpected node kind: ",
+        std::to_string(
+          static_cast<std::uint32_t>(kind)
+        )
+      )
+    );
+  }
+
+  return it->second;
+}
+
+// endregion Node kind
+
+std::string NodeToHumanReadableString(
+  const INode& node
+) {
+  switch (node.kind()) {
+    case NodeKind::Bof:
+      return "beginning-of-input";
+
+    case NodeKind::Start:
+    case NodeKind::StartInNoNamespace: {
+      const StartNode& start_node(
+        static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const StartNode&
+        >(node)
+      );
+
+      return common::Concat(
+        "a start node <",
+        start_node.name,
+        ">"
+      );
+    }
+
+    case NodeKind::Stop:
+    case NodeKind::StopInNoNamespace: {
+      const StopNode& stop_node(
+        static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const StopNode&
+        >(node)
+      );
+
+      return common::Concat(
+        "a stop node </",
+        stop_node.name,
+        ">"
+      );
+    }
+
+    case NodeKind::Text:
+      return "an XML text";
+
+    case NodeKind::Eof:
+      return "end-of-input";
+
+    case NodeKind::Error:
+      return "an XML error";
+
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected node kind: ",
+          std::to_string(
+            static_cast<std::uint32_t>(node.kind())
+          )
+        )
+      );
+  }
+}
+
+std::wstring NodeToHumanReadableWstring(
+  const INode& node
+) {
+  switch (node.kind()) {
+    case NodeKind::Bof:
+      return L"beginning-of-input";
+
+    case NodeKind::Start:
+    case NodeKind::StartInNoNamespace: {
+      const StartNode& start_node(
+        static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const StartNode&
+        >(node)
+      );
+
+      return common::Concat(
+        L"a start node <",
+        common::Utf8ToWstring(start_node.name),
+        L">"
+      );
+    }
+
+    case NodeKind::Stop:
+    case NodeKind::StopInNoNamespace: {
+      const StopNode& stop_node(
+        static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+          const StopNode&
+        >(node)
+      );
+
+      return common::Concat(
+        L"a stop node </",
+        common::Utf8ToWstring(stop_node.name),
+        L">"
+      );
+    }
+
+    case NodeKind::Text:
+      return L"an XML text";
+
+    case NodeKind::Eof:
+      return L"end-of-input";
+
+    case NodeKind::Error:
+      return L"an XML error";
+
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Unexpected node kind: ",
+          std::to_string(
+            static_cast<std::uint32_t>(node.kind())
+          )
+        )
+      );
+  }
+}
+
+bool IsStopNodeWithName(
+  const INode& node,
+  const std::string& expected_name
+) {
+  if (node.kind() != NodeKind::Stop) {
+    return false;
+  }
+
+  const std::string& name(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const StopNode&
+    >(node).name
+  );
+  if (name != expected_name) {
+    return false;
+  }
+
+  return true;
+}
+
+bool IsStopNodeWithNameInNoNamespace(
+  const INode& node,
+  const std::string& expected_name
+) {
+  if (node.kind() != NodeKind::StopInNoNamespace) {
+    return false;
+  }
+
+  const std::string& name(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const StopNode&
+    >(node).name
+  );
+  if (name != expected_name) {
+    return false;
+  }
+
+  return true;
+}
+
+// region XSD lexical forms
+
+std::string CollapseWhitespace(const std::string& text) {
+  std::string result;
+  result.reserve(text.size());
+
+  bool pending_space = false;
+  for (const char character : text) {
+    if (
+      character == ' '
+      || character == '\t'
+      || character == '\n'
+      || character == '\r'
+    ) {
+      // NOTE (mristin):
+      // A space is only worth keeping once something has come before it,
+      // which trims the leading ones, and it is written out only when
+      // something follows, which trims the trailing ones.
+      pending_space = !result.empty();
+    } else {
+      if (pending_space) {
+        result += ' ';
+        pending_space = false;
+      }
+      result += character;
+    }
+  }
+
+  return result;
+}
+
+bool MatchesXsLongNumeral(const std::string& text) {
+  std::size_t cursor = 0;
+  const std::size_t size = text.size();
+
+  if (cursor < size && (text[cursor] == '+' || text[cursor] == '-')) {
+    ++cursor;
+  }
+
+  std::size_t digits = 0;
+  while (cursor < size && text[cursor] >= '0' && text[cursor] <= '9') {
+    ++cursor;
+    ++digits;
+  }
+
+  return digits > 0 && cursor == size;
+}
+
+bool MatchesXsDoubleNumeral(const std::string& text) {
+  std::size_t cursor = 0;
+  const std::size_t size = text.size();
+
+  if (cursor < size && (text[cursor] == '+' || text[cursor] == '-')) {
+    ++cursor;
+  }
+
+  std::size_t digits_before_the_point = 0;
+  while (cursor < size && text[cursor] >= '0' && text[cursor] <= '9') {
+    ++cursor;
+    ++digits_before_the_point;
+  }
+
+  std::size_t digits_after_the_point = 0;
+  if (cursor < size && text[cursor] == '.') {
+    ++cursor;
+    while (cursor < size && text[cursor] >= '0' && text[cursor] <= '9') {
+      ++cursor;
+      ++digits_after_the_point;
+    }
+  }
+
+  // NOTE (mristin):
+  // A numeral needs a digit somewhere, but on either side of the point will
+  // do: both "1." and ".5" are good xs:double numerals.
+  if (digits_before_the_point == 0 && digits_after_the_point == 0) {
+    return false;
+  }
+
+  if (cursor < size && (text[cursor] == 'e' || text[cursor] == 'E')) {
+    ++cursor;
+
+    if (cursor < size && (text[cursor] == '+' || text[cursor] == '-')) {
+      ++cursor;
+    }
+
+    std::size_t digits_in_the_exponent = 0;
+    while (cursor < size && text[cursor] >= '0' && text[cursor] <= '9') {
+      ++cursor;
+      ++digits_in_the_exponent;
+    }
+
+    if (digits_in_the_exponent == 0) {
+      return false;
+    }
+  }
+
+  return cursor == size;
+}
+
+bool MatchesXsBase64Binary(const std::string& text) {
+  if (text.size() % 4 != 0) {
+    return false;
+  }
+
+  if (text.empty()) {
+    return true;
+  }
+
+  std::size_t pads = 0;
+  if (text[text.size() - 1] == '=') {
+    pads = 1;
+    if (text[text.size() - 2] == '=') {
+      pads = 2;
+    }
+  }
+
+  for (std::size_t i = 0; i < text.size() - pads; ++i) {
+    const char character = text[i];
+    const bool in_alphabet(
+      (character >= 'A' && character <= 'Z')
+        || (character >= 'a' && character <= 'z')
+        || (character >= '0' && character <= '9')
+        || character == '+'
+        || character == '/'
+    );
+    if (!in_alphabet) {
+      return false;
+    }
+  }
+
+  // NOTE (mristin):
+  // Only these sixteen characters leave the two dropped bits at zero, and
+  // only these four leave the four dropped bits at zero.
+  if (pads == 1) {
+    return std::string("AEIMQUYcgkosw048").find(text[text.size() - 2])
+      != std::string::npos;
+  }
+
+  if (pads == 2) {
+    return std::string("AQgw").find(text[text.size() - 3])
+      != std::string::npos;
+  }
+
+  return true;
+}
+
+std::string RemoveWhitespace(const std::string& text) {
+  std::string result;
+  result.reserve(text.size());
+
+  for (const char character : text) {
+    if (
+      character != ' '
+      && character != '\t'
+      && character != '\n'
+      && character != '\r'
+    ) {
+      result += character;
+    }
+  }
+
+  return result;
+}
+
+// endregion XSD lexical forms
+
+// region class Reader
+
+/**
+ * Structure the data passed over to Expat XML reader.
+ */
+struct OurData {
+  bool additional_attributes;
+  size_t buffer_size;
+  XML_Parser parser;
+
+  std::deque<std::unique_ptr<INode> >& node_buffer;
+
+  bool stopped = false;
+
+  OurData(
+    bool the_additional_attributes,
+    size_t a_buffer_size,
+    XML_Parser a_parser,
+    std::deque<std::unique_ptr<INode> >& a_node_buffer
+  ) :
+    additional_attributes(the_additional_attributes),
+    buffer_size(a_buffer_size),
+    parser(a_parser),
+    node_buffer(a_node_buffer) {
+    // Intentionally empty.
+  }
+};  // struct OurData
+
+Reader::Reader(
+  std::istream& is,
+  bool additional_attributes,
+  size_t buffer_size
+) :
+  additional_attributes_(additional_attributes),
+  buffer_size_(buffer_size),
+  is_(is),
+  parser_(nullptr),
+  current_(common::make_unique<BofNode>()),
+  eof_(false),
+  error_(false) {
+  // Intentionally empty.
+}
+
+const char kNamespaceSeparator = '|';
+
+void XMLCALL OnStartElement(
+  void* user_data,
+  const char* name,
+  const char* attributes[]
+) {
+  auto our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->stopped) {
+    return;
+  }
+
+  const std::string name_str(name);
+
+  // NOTE (mristin):
+  // Expat spells a namespaced element as `namespace|local`, and an element
+  // in no namespace as the bare local name. We accept the both: the elements
+  // of the document reside in \ref kNamespace, and the elements of
+  // the XML-RPC subset in no namespace at all. Which of the two is expected
+  // where is decided by the caller, as it depends on the grammar and not on
+  // the document.
+  size_t separator_i = name_str.find(kNamespaceSeparator);
+
+  const bool in_namespace = separator_i != std::string::npos;
+
+  if (separator_i == 0) {
+    std::string message = common::Concat(
+      "The namespace is empty in the start element <",
+      name_str,
+      ">"
+    );
+
+    our_data->node_buffer.emplace_back(
+      common::make_unique<ErrorNode>(
+        XML_GetCurrentLineNumber(our_data->parser),
+        XML_GetCurrentColumnNumber(our_data->parser),
+        message
+      )
+    );
+
+    XML_StopParser(our_data->parser, false);
+    our_data->stopped = true;
+    return;
+  }
+
+  const std::string local_name(
+    in_namespace
+      ? name_str.substr(separator_i + 1)
+      : name_str
+  );
+
+  if (
+    in_namespace
+    && name_str.compare(0, separator_i, kNamespace) != 0
+  ) {
+    std::string message = common::Concat(
+      "We expected the XML namespace ",
+      kNamespace,
+      ", or no namespace at all, but we got the namespace ",
+      name_str.substr(0, separator_i),
+      " in the start element <",
+      local_name,
+      ">"
+    );
+
+    our_data->node_buffer.emplace_back(
+      common::make_unique<ErrorNode>(
+        XML_GetCurrentLineNumber(our_data->parser),
+        XML_GetCurrentColumnNumber(our_data->parser),
+        message
+      )
+    );
+
+    XML_StopParser(our_data->parser, false);
+    our_data->stopped = true;
+    return;
+  }
+
+  if (
+    attributes[0] != nullptr
+    && !(our_data->additional_attributes)
+  ) {
+    std::string message = common::Concat(
+      "Additional attributes are not allowed, "
+      "but the attribute ",
+      attributes[0],
+      " was read in the start element <",
+      local_name,
+      ">"
+    );
+
+    our_data->node_buffer.emplace_back(
+      common::make_unique<ErrorNode>(
+        XML_GetCurrentLineNumber(our_data->parser),
+        XML_GetCurrentColumnNumber(our_data->parser),
+        message
+      )
+    );
+
+    XML_StopParser(our_data->parser, false);
+    our_data->stopped = true;
+    return;
+  }
+
+  our_data->node_buffer.emplace_back(
+    common::make_unique<StartNode>(
+      local_name,
+      in_namespace
+    )
+  );
+}
+
+void XMLCALL OnStopElement(
+  void* user_data,
+  const char* name
+) {
+  auto* our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->stopped) {
+    return;
+  }
+
+  const std::string name_str(name);
+
+  size_t separator_i = name_str.find(kNamespaceSeparator);
+
+  const bool in_namespace = separator_i != std::string::npos;
+
+  if (separator_i == 0) {
+    std::string message = common::Concat(
+      "The namespace is empty in the stop element </",
+      name_str,
+      ">"
+    );
+
+    our_data->node_buffer.emplace_back(
+      common::make_unique<ErrorNode>(
+        XML_GetCurrentLineNumber(our_data->parser),
+        XML_GetCurrentColumnNumber(our_data->parser),
+        message
+      )
+    );
+
+    XML_StopParser(our_data->parser, false);
+    our_data->stopped = true;
+    return;
+  }
+
+  const std::string local_name(
+    in_namespace
+      ? name_str.substr(separator_i + 1)
+      : name_str
+  );
+
+  if (
+    in_namespace
+    && name_str.compare(0, separator_i, kNamespace) != 0
+  ) {
+    std::string message = common::Concat(
+      "We expected the XML namespace ",
+      kNamespace,
+      ", or no namespace at all, but we got the namespace ",
+      name_str.substr(0, separator_i),
+      " in the stop element </",
+      local_name,
+      ">"
+    );
+
+    our_data->node_buffer.emplace_back(
+      common::make_unique<ErrorNode>(
+        XML_GetCurrentLineNumber(our_data->parser),
+        XML_GetCurrentColumnNumber(our_data->parser),
+        message
+      )
+    );
+
+    XML_StopParser(our_data->parser, false);
+    our_data->stopped = true;
+    return;
+  }
+
+  our_data->node_buffer.emplace_back(
+    common::make_unique<StopNode>(
+      local_name,
+      in_namespace
+    )
+  );
+}
+
+void XMLCALL OnText(
+  void* user_data,
+  const char* val,
+  int len
+) {
+  auto our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->stopped) {
+    return;
+  }
+
+  our_data->node_buffer.emplace_back(
+    common::make_unique<TextNode>(
+      std::string(val, len)
+    )
+  );
+}
+
+void Reader::Initialize() {
+  // NOTE (mristin):
+  // We set up the underlying parser here instead of the constructor
+  // to avoid throwing exceptions in the constructor.
+
+  if (parser_ != nullptr) {
+    throw std::logic_error(
+      "You are trying to re-initialize an initialized XML reader."
+    );
+  }
+
+  if (
+    buffer_size_
+    > static_cast<size_t>(
+      (std::numeric_limits<int>::max)()
+    )
+  ) {
+    throw std::invalid_argument(
+      common::Concat(
+        "Expat library expects the buffer size as int, "
+        "but the given buffer size ",
+        std::to_string(buffer_size_),
+        " does not fit in an int as it is larger than the maximum int ",
+        std::to_string(std::numeric_limits<int>::max())
+      )
+    );
+  }
+
+  parser_ = XML_ParserCreateNS(nullptr, kNamespaceSeparator);
+  our_data_ = common::make_unique<OurData>(
+    additional_attributes_,
+    buffer_size_,
+    parser_,
+    node_buffer_
+  );
+
+  XML_SetUserData(parser_, our_data_.get());
+  XML_SetElementHandler(
+    parser_,
+    OnStartElement,
+    OnStopElement
+  );
+  XML_SetCharacterDataHandler(parser_, OnText);
+
+  chunk_.resize(buffer_size_);
+
+  Read();
+}
+
+void Reader::Read() {
+  if (parser_ == nullptr) {
+    throw std::logic_error(
+      "You are trying to read from an uninitialized XML reader"
+    );
+  }
+
+  if (eof_) {
+    throw std::logic_error(
+      "The XML reader reached the end-of-input, "
+      "but you called Read()"
+    );
+  }
+
+  if (error_) {
+    throw std::logic_error(
+      "There was an error while reading XML, "
+      "but you called Read() again"
+    );
+  }
+
+  while (node_buffer_.empty()) {
+    // NOTE (mristin):
+    // We read and parse the next chunk of input, until we parsed a whole node.
+    // The text, however, will be fragmented by Expat's design.
+
+    is_.read(&(chunk_[0]), buffer_size_);
+
+    const std::streamsize actual_bytes_read = is_.gcount();
+
+    if (is_.bad()) {
+      SetCurrentAndEofAndError(
+        common::make_unique<ErrorNode>(
+          0,
+          0,
+          "Failed to read from the input"
+        )
+      );
+      return;
+    }
+
+    if (actual_bytes_read == 0) {
+      if (is_.eof()) {
+        SetCurrentAndEofAndError(common::make_unique<EofNode>());
+        return;
+      } else {
+        SetCurrentAndEofAndError(
+          common::make_unique<ErrorNode>(
+            0,
+            0,
+            "Read zero bytes from the input, "
+            "but the input is neither eof() nor bad()"
+          )
+        );
+        return;
+      }
+    } else {
+      const bool done = is_.eof();
+
+      if (actual_bytes_read > std::numeric_limits<int>::max()) {
+        std::string message = common::Concat(
+          "Expat library expects the buffer size as int, ",
+          "but the actual number of bytes read ",
+          std::to_string(actual_bytes_read),
+          " does not fit in an int as it is larger than the maximum int ",
+          std::to_string(std::numeric_limits<int>::max())
+        );
+
+        throw std::runtime_error(message);
+      }
+
+      const auto actual_bytes_read_int = static_cast<int>(actual_bytes_read);
+
+      XML_Status status = XML_Parse(
+        parser_,
+        &(chunk_[0]),
+        actual_bytes_read_int,
+        done
+      );
+
+      if (status == XML_STATUS_ERROR) {
+        XML_Error error_code = XML_GetErrorCode(parser_);
+
+        if (error_code == XML_ERROR_ABORTED) {
+          if (node_buffer_.empty()) {
+            throw std::logic_error(
+              "The XML parsing was aborted, "
+              "so we expected an error node on the buffer, "
+              "but the buffer was empty"
+            );
+          }
+
+          if (node_buffer_.back()->kind() != NodeKind::Error) {
+            std::string message = common::Concat(
+              "The XML parsing was aborted, "
+              "so we expected an error node on the buffer, "
+              "but we got ",
+              NodeKindToHumanReadableString(node_buffer_.back()->kind())
+            );
+
+            throw std::logic_error(message);
+          }
+        } else {
+          const XML_LChar* error_str = XML_ErrorString(error_code);
+
+          node_buffer_.emplace_back(
+            common::make_unique<ErrorNode>(
+              XML_GetCurrentLineNumber(parser_),
+              XML_GetCurrentColumnNumber(parser_),
+              std::string(error_str)
+            )
+          );
+        }
+      } else {
+        if (done) {
+          node_buffer_.emplace_back(common::make_unique<EofNode>());
+        }
+      }
+    }
+  }
+
+  SetCurrentAndEofAndError(std::move(node_buffer_.front()));
+  node_buffer_.pop_front();
+}
+
+const INode& Reader::node() const {
+  return *current_;
+}
+
+std::unique_ptr<INode> Reader::moved_node() {
+  return std::move(current_);
+}
+
+Reader::~Reader() {
+  if (parser_ != nullptr) {
+    XML_ParserFree(parser_);
+  }
+}
+
+void Reader::SetCurrentAndEofAndError(
+  std::unique_ptr<INode> node
+) {
+  current_ = std::move(node);
+
+  #ifdef __clang__
+  #pragma clang diagnostic push
+  #pragma clang diagnostic ignored "-Wswitch"
+  #endif
+  switch (current_->kind()) {
+    case NodeKind::Eof:
+      eof_ = true;
+      break;
+    case NodeKind::Error:
+      error_ = true;
+      break;
+  }
+  #ifdef __clang__
+  #pragma clang diagnostic pop
+  #endif
+}
+
+// endregion class Reader
+
+// region class ReaderMergingText
+
+ReaderMergingText::ReaderMergingText(
+    std::istream& is,
+    bool additional_attributes,
+    size_t buffer_size
+) :
+  initialized_(false),
+  reader_(is, additional_attributes, buffer_size),
+  current_(common::make_unique<BofNode>()),
+  error_(false),
+  eof_(false) {
+  // Intentionally empty.
+}
+
+void ReaderMergingText::Initialize() {
+  if (initialized_) {
+    throw std::logic_error(
+      "You are trying to initialize "
+      "an already initialized ReaderMergingText"
+    );
+  }
+
+  reader_.Initialize();
+
+  // NOTE (mristin):
+  // The `reader_` has already read a node. Hence, we need to parse it here
+  // separately from `ReaderMergingText::Read` method.
+
+  if (reader_.node().kind() != NodeKind::Text) {
+    SetCurrentAndEofAndError(reader_.moved_node());
+  } else {
+    ReadAndMergeAllTextAndSetLookahead();
+  }
+
+  initialized_ = true;
+}
+
+void ReaderMergingText::Read() {
+  if (!initialized_) {
+    throw std::logic_error(
+      "You are reading from an uninitialized ReaderMergingText"
+    );
+  }
+
+  if (eof()) {
+    throw std::logic_error(
+      "You are trying to read from a ReaderMergingText, "
+      "but it reached the end-of-input"
+    );
+  }
+
+  if (error()) {
+    throw std::logic_error(
+      "You are trying to read from a ReaderMergingText, "
+      "but an error already occurred"
+    );
+  }
+
+  if (look_ahead_ != nullptr) {
+    SetCurrentAndEofAndError(std::move(look_ahead_));
+    return;
+  }
+
+  reader_.Read();
+  if (reader_.node().kind() != NodeKind::Text) {
+    SetCurrentAndEofAndError(reader_.moved_node());
+  } else {
+    ReadAndMergeAllTextAndSetLookahead();
+  }
+}
+
+const INode& ReaderMergingText::node() const {
+  return *current_;
+}
+
+bool ReaderMergingText::error() const {
+  return error_;
+}
+
+bool ReaderMergingText::eof() const {
+  return eof_;
+}
+
+void ReaderMergingText::ReadAndMergeAllTextAndSetLookahead() {
+  if (reader_.node().kind() != NodeKind::Text) {
+    std::string message = common::Concat(
+      "Expected the current node in the reader "
+      "underlying ReaderMergingText to be a text, "
+      "but it was ",
+      NodeKindToHumanReadableString(reader_.node().kind())
+    );
+
+    throw std::logic_error(message);
+  }
+
+  std::deque<std::string> text_buffer;
+
+  while (reader_.node().kind() == NodeKind::Text) {
+    const TextNode& fragment_text_node(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const TextNode&
+      >(
+        reader_.node()
+      )
+    );
+
+    text_buffer.emplace_back(fragment_text_node.text);
+
+    reader_.Read();
+  }
+  look_ahead_ = reader_.moved_node();
+
+  size_t size = 0;
+  for (const std::string& fragment : text_buffer) {
+    size += fragment.size();
+  }
+
+  std::string text;
+  text.reserve(size);
+  while (!text_buffer.empty()) {
+    text.append(text_buffer.front());
+    text_buffer.pop_front();
+  }
+
+  SetCurrentAndEofAndError(common::make_unique<TextNode>(text));
+}
+
+void ReaderMergingText::SetCurrentAndEofAndError(std::unique_ptr<INode> node) {
+  current_ = std::move(node);
+
+  #ifdef __clang__
+  #pragma clang diagnostic push
+  #pragma clang diagnostic ignored "-Wswitch"
+  #endif
+  switch (current_->kind()) {
+    case NodeKind::Eof:eof_ = true;
+      break;
+    case NodeKind::Error:error_ = true;
+      break;
+  }
+  #ifdef __clang__
+  #pragma clang diagnostic pop
+  #endif
+}
+
+// endregion class ReaderMergingText
+
+SerializationError::SerializationError(
+  std::wstring a_cause
+) :
+  cause(std::move(a_cause)) {
+  // Intentionally empty.
+}
+
+const std::wstring kTheOutputStreamIsInABadState(
+    L"The output stream is in a bad state."
+);
+
+common::optional<SerializationError> CheckOstreamState(
+  const std::ostream& os
+) {
+  if (os.bad()) {
+    return common::make_optional<SerializationError>(
+      kTheOutputStreamIsInABadState
+    );
+  }
+
+  return common::nullopt;
+}
+
+// region class SelfClosingWriter
+
+SelfClosingWriter::SelfClosingWriter(
+  std::ostream& os,
+  const char* root_attributes
+) :
+  os_(os),
+  root_attributes_(root_attributes),
+  pending_attributes_("") {
+  // Intentionally empty.
+}
+
+void SelfClosingWriter::StartElement(
+  std::string name
+) {
+  #ifdef DEBUG
+  if (error_.has_value()) {
+    throw std::logic_error(
+      "You are trying to queue a start element with a SelfClosingWriter "
+      "which caught an error."
+    );
+  }
+  #endif
+
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  pending_start_wo_text_ = std::move(name);
+
+  // NOTE (mristin):
+  // The outermost element carries the attributes of the root, and every other
+  // element carries none. We take them here instead of asking whether this is
+  // the first element, since the assignment has to happen either way.
+  pending_attributes_ = root_attributes_;
+  root_attributes_ = "";
+}
+
+void SelfClosingWriter::StopElement(
+  const std::string& name
+) {
+  #ifdef DEBUG
+  if (error_.has_value()) {
+    throw std::logic_error(
+      "You are trying to write a stop element with a SelfClosingWriter "
+      "which caught an error before."
+    );
+  }
+  #endif
+
+  if (pending_start_wo_text_.has_value()) {
+    #ifdef DEBUG
+    if (*pending_start_wo_text_ != name) {
+      throw std::logic_error(
+        common::Concat(
+          "The start element <",
+          *pending_start_wo_text_,
+          "> is pending for writing, "
+          "but you are trying to write a stop element </",
+          name,
+          ">"
+        )
+      );
+    }
+    #endif
+
+    pending_start_wo_text_ = common::nullopt;
+
+    WriteStringWithoutEscapingNorFlushing(
+      common::Concat(
+        "<",
+        name,
+        pending_attributes_,
+        "/>"
+      )
+    );
+  } else {
+    WritePendingStartElementIfAvailable();
+    if (error_.has_value()) {
+      return;
+    }
+
+    WriteStringWithoutEscapingNorFlushing(
+      common::Concat(
+        "</",
+        name,
+        ">"
+      )
+    );
+  }
+}
+
+void SelfClosingWriter::SerializeBool(
+  bool value
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  WriteStringWithoutEscapingNorFlushing(
+    value ? "true" : "false"
+  );
+}
+
+void SelfClosingWriter::SerializeInt64(
+  int64_t value
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  WriteStringWithoutEscapingNorFlushing(
+    std::to_string(value)
+  );
+}
+
+void SelfClosingWriter::SerializeDouble(
+  double value
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  // NOTE (mristin):
+  // We handle edge values infinity and not-a-number explicitly here
+  // as some C/C++ implementations might not convert them to XML-conformant
+  // strings.
+
+  if (std::isinf(value)) {
+    if (value < 0) {
+      WriteStringWithoutEscapingNorFlushing("-INF");
+    } else {
+      WriteStringWithoutEscapingNorFlushing("INF");
+    }
+  } else if(std::isnan(value)) {
+    WriteStringWithoutEscapingNorFlushing("NaN");
+  } else {
+    // NOTE (mristin):
+    // We have to use a stream to avoid trailing zeros. std::to_string always
+    // outputs trailing zeros up to a certain number of decimal places (usually 6).
+    //
+    // A stream left at its default precision is no good either: that is six
+    // *significant* digits, so 1.2345678901234567 would go out as 1.23457, and
+    // the value could never be read back. We have to write as many digits as it
+    // takes for the text to read back as the very same double, and no more.
+    //
+    // std::to_chars would give us exactly that in one call, but it is C++17,
+    // and the library has to compile as C++11. Seventeen significant digits
+    // always suffice, and fewer usually do, so the candidates are tried in
+    // turn and the first one which round-trips is kept. The stream strips
+    // the trailing zeros of each, so a short value stays short.
+    //
+    // The classic locale is imposed on both streams: a global locale with
+    // a decimal comma would otherwise write 1,2345, which no XML parser reads
+    // back as a number.
+    std::ostringstream oss;
+    oss.imbue(std::locale::classic());
+
+    for (int precision = 15; precision <= 17; ++precision) {
+      oss.str("");
+      oss.clear();
+      oss << std::setprecision(precision) << value;
+
+      std::istringstream iss(oss.str());
+      iss.imbue(std::locale::classic());
+      double round_tripped = 0.0;
+      iss >> round_tripped;
+
+      // NOTE (mristin):
+      // The failbit has to be consulted, and not only the value. On overflow
+      // the stream stores the largest representable double and *fails*, so
+      // comparing the value alone would accept a text which every correctly
+      // rounding parser reads as an infinity: 15 significant digits of
+      // the largest double give 1.79769313486232e+308, which lies above
+      // the overflow threshold.
+      if (!iss.fail() && round_tripped == value) {
+        break;
+      }
+    }
+
+    WriteStringWithoutEscapingNorFlushing(
+      oss.str()
+    );
+  }
+}
+
+void SelfClosingWriter::SerializeString(
+  const std::string& text
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  // NOTE (mristin):
+  // We optimize here for short and long texts, respectively.
+  // The main assumption is that the short texts can be escaped and converted
+  // in one go, while the longer texts need to be converted in chunks.
+
+  if (text.size() < 1024) {
+    common::optional<std::string> escaped = EscapeForXml(text);
+
+    if (escaped.has_value()) {
+      WriteStringWithoutEscapingNorFlushing(
+        *escaped
+      );
+      return;
+    } else {
+      WriteStringWithoutEscapingNorFlushing(
+        text
+      );
+      return;
+    }
+  }
+
+  size_t start = 0;
+  while (start < text.size()) {
+    const size_t end = std::min(start + 1024, text.size());
+    const size_t chunk_size = end - start;
+
+    // NOTE (mristin):
+    // We assume that making short copies of text substrings does not hurt
+    // the performance here, but makes the code more readable.
+
+    const std::string chunk = text.substr(start, chunk_size);
+
+    common::optional<std::string> escaped = EscapeForXml(chunk);
+
+    if (escaped.has_value()) {
+      WriteStringWithoutEscapingNorFlushing(
+        *escaped
+      );
+    } else {
+      WriteStringWithoutEscapingNorFlushing(
+        chunk
+      );
+    }
+
+    if (error_.has_value()) {
+      return;
+    }
+
+    start += chunk_size;
+  }
+}
+
+void SelfClosingWriter::SerializeWstring(
+  const std::wstring& text
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  // NOTE (mristin):
+  // We optimize here for short and long texts, respectively.
+  // The main assumption is that the short texts can be escaped and converted
+  // in one go, while the longer texts need to be converted in chunks.
+
+  if (text.size() < 1024) {
+    common::optional<std::wstring> escaped = EscapeForXml(text);
+
+    if (escaped.has_value()) {
+      WriteStringWithoutEscapingNorFlushing(
+        common::WstringToUtf8(*escaped)
+      );
+      return;
+    } else {
+      WriteStringWithoutEscapingNorFlushing(
+        common::WstringToUtf8(text)
+      );
+      return;
+    }
+  }
+
+  size_t start = 0;
+  while (start < text.size()) {
+    const size_t end = std::min(start + 1024, text.size());
+    const size_t chunk_size = end - start;
+
+    // NOTE (mristin):
+    // We assume that making short copies of text substrings does not hurt
+    // the performance here, but makes the code more readable.
+
+    const std::wstring chunk = text.substr(start, chunk_size);
+
+    common::optional<std::wstring> escaped = EscapeForXml(chunk);
+
+    if (escaped.has_value()) {
+      WriteStringWithoutEscapingNorFlushing(
+        common::WstringToUtf8(*escaped)
+      );
+    } else {
+      WriteStringWithoutEscapingNorFlushing(
+        common::WstringToUtf8(chunk)
+      );
+    }
+
+    if (error_.has_value()) {
+      return;
+    }
+
+    start += chunk_size;
+  }
+}
+
+void SelfClosingWriter::SerializeByteArray(
+  const std::vector<std::uint8_t>& byte_array
+) {
+  WritePendingStartElementIfAvailable();
+  if (error_.has_value()) {
+    return;
+  }
+
+  // NOTE (mristin):
+  // We optimize here for short and long byte arrays, respectively.
+  // The main assumption is that the short texts can be escaped and converted
+  // in one go, while the longer texts need to be converted in chunks.
+  //
+  // Optimally, we would write an encoding function such that it encodes directly
+  // to the output stream. As we lack the time resources for that at the moment,
+  // we go for the compromise with one pass and chunking, respectively.
+
+  if (byte_array.size() <= 1536) {
+    WriteStringWithoutEscapingNorFlushing(
+      stringification::Base64Encode(byte_array)
+    );
+    return;
+  }
+
+  // NOTE (mristin):
+  // We assume here that making copies of small sub-arrays does not hurt
+  // the performance, but makes the code substantially more readable.
+
+  size_t start = 0;
+  while (start < byte_array.size()) {
+    // NOTE (mristin):
+    // We pick a multiple of 3 for the chunk size in order to make the encoding
+    // of chunking identical to the output as we encoded all bytes at the same time.
+    //
+    // See: https://stackoverflow.com/questions/7920780/is-it-possible-to-base64-encode-a-file-in-chunks
+
+    const size_t end = std::min(start + 1536, byte_array.size());
+
+    const std::vector<std::uint8_t> chunk(
+      byte_array.begin() + start,
+      byte_array.begin() + end
+    );
+
+    WriteStringWithoutEscapingNorFlushing(
+      stringification::Base64Encode(chunk)
+    );
+    if (error_.has_value()) {
+      return;
+    }
+  }
+}
+
+void SelfClosingWriter::Finish() {
+  WritePendingStartElementIfAvailable();
+}
+
+const common::optional<SerializationError>& SelfClosingWriter::error() const {
+  return error_;
+}
+
+common::optional<SerializationError>&& SelfClosingWriter::move_error() {
+  return std::move(error_);
+}
+
+common::optional<std::wstring> SelfClosingWriter::EscapeForXml(
+  const std::wstring& text
+) {
+  size_t out_len = 0;
+
+  // NOTE (mristin):
+  // We use sizeof on *strings* instead of *wide strings* to get
+  // the number of *characters*. Otherwise, if we used wide strings,
+  // we would obtain the wrong number of characters as we would count
+  // bytes instead of characters with `sizeof`, which differ in wide strings
+  // due to encoding.
+
+  for (wchar_t character : text ) {
+    switch (character) {
+      case L'&': {
+        out_len += sizeof("&amp;");
+        break;
+      }
+      case L'<': {
+        out_len += sizeof("&lt;");
+        break;
+      }
+      case L'>': {
+        out_len += sizeof("&gt;");
+        break;
+      }
+      case L'"': {
+        out_len += sizeof("&quot;");
+        break;
+      }
+      case L'\'': {
+        out_len += sizeof("&apos;");
+        break;
+      }
+      default:
+        ++out_len;
+        break;
+    }
+  }
+
+  // NOTE (mristin):
+  // We assume here that XML encoding is always *longer* than
+  // the original text.
+
+  if (out_len == text.size()) {
+    return common::nullopt;
+  }
+
+  std::wstring out;
+  out.reserve(out_len);
+
+  for (wchar_t character : text ) {
+    switch (character) {
+      case L'&':
+        out.append(L"&amp;");
+        break;
+      case L'<':
+        out.append(L"&lt;");
+        break;
+      case L'>':
+        out.append(L"&gt;");
+        break;
+      case L'"':
+        out.append(L"&quot;");
+        break;
+      case L'\'':
+        out.append(L"&apos;");
+        break;
+      default:
+        out.push_back(character);
+        break;
+    }
+  }
+
+  return common::make_optional<std::wstring>(
+    std::move(out)
+  );
+}
+
+common::optional<std::string> SelfClosingWriter::EscapeForXml(
+  const std::string& text
+) {
+  size_t out_len = 0;
+
+  for (char character : text ) {
+    switch (character) {
+      case '&': {
+        out_len += sizeof("&amp;");
+        break;
+      }
+      case '<': {
+        out_len += sizeof("&lt;");
+        break;
+      }
+      case '>': {
+        out_len += sizeof("&gt;");
+        break;
+      }
+      case '"': {
+        out_len += sizeof("&quot;");
+        break;
+      }
+      case '\'': {
+        out_len += sizeof("&apos;");
+        break;
+      }
+      default:
+        ++out_len;
+        break;
+    }
+  }
+
+  // NOTE (mristin):
+  // We assume here that XML encoding is always *longer* than
+  // the original text.
+
+  if (out_len == text.size()) {
+    return common::nullopt;
+  }
+
+  std::string out;
+  out.reserve(out_len);
+
+  for (char character : text ) {
+    switch (character) {
+      case '&':
+        out.append("&amp;");
+        break;
+      case '<':
+        out.append("&lt;");
+        break;
+      case '>':
+        out.append("&gt;");
+        break;
+      case '"':
+        out.append("&quot;");
+        break;
+      case '\'':
+        out.append("&apos;");
+        break;
+      default:
+        out.push_back(character);
+        break;
+    }
+  }
+
+  return common::make_optional<std::string>(
+    std::move(out)
+  );
+}
+
+void SelfClosingWriter::WritePendingStartElementIfAvailable() {
+  if (!pending_start_wo_text_.has_value()) {
+    return;
+  }
+
+  WriteStringWithoutEscapingNorFlushing(
+    common::Concat(
+      "<",
+      *pending_start_wo_text_,
+      pending_attributes_,
+      ">"
+    )
+  );
+
+  pending_start_wo_text_ = common::nullopt;
+}
+
+void SelfClosingWriter::WriteStringWithoutEscapingNorFlushing(
+  const std::string& text
+) {
+  #ifdef DEBUG
+  if (error_.has_value()) {
+    throw std::logic_error(
+      "You are trying to write to a SelfClosingWriter which "
+      "caught an error"
+    );
+  }
+  #endif
+
+  if (os_.bad()) {
+    error_ = common::make_optional<SerializationError>(
+      kTheOutputStreamIsInABadState
+    );
+    return;
+  }
+
+  os_ << text;
+
+  if (os_.bad()) {
+    error_ = common::make_optional<SerializationError>(
+      kTheOutputStreamIsInABadState
+    );
+    return;
+  }
+}
+
+// endregion class SelfClosingWriter
+
+}  // namespace xml_common
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.hpp
new file mode 100644
index 000000000..f74c5007b
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_common.hpp
@@ -0,0 +1,676 @@
+#ifndef DUMMY_XML_COMMON_GUARD_
+#define DUMMY_XML_COMMON_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/common.hpp"
+#include "dummy/iteration.hpp"
+
+#pragma warning(push, 0)
+#include <expat.h>
+
+#include <cstdint>
+#include <deque>
+#include <iosfwd>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+
+namespace xml_common {
+
+/**
+ * \brief The XML namespace in which all the elements of a document reside.
+ *
+ * The elements of the XML-RPC subset, over which a JSON-able value is
+ * de/serialized, are the one exception: they reside in no namespace at all.
+ */
+extern const char* const kNamespace;
+
+// region Node kind
+
+enum class NodeKind : std::uint32_t {
+  // Nodes of the kind `Bof` represent the beginning-of-input, before any read.
+  Bof = 0,
+  // Nodes of the kind `Start` and `Stop` represent an element which resides in
+  // \ref kNamespace.
+  Start = 1,
+  Stop = 2,
+  Text = 3,
+  // Nodes of the kind `Eof` represent the end-of-input.
+  Eof = 4,
+  // Nodes of the kind `Error` represent low-level errors in the XML parsing.
+  Error = 5,
+  // Nodes of the kind `StartInNoNamespace` and `StopInNoNamespace` represent
+  // an element which resides in no namespace at all. Only the XML-RPC subset,
+  // over which a JSON-able value is de/serialized, is written like that.
+  StartInNoNamespace = 6,
+  StopInNoNamespace = 7
+};  // enum class NodeKind
+
+extern const std::unordered_map<
+    NodeKind,
+    std::string
+> kNodeKindToHumanReadableString;
+
+const std::string& NodeKindToHumanReadableString(NodeKind kind);
+
+// endregion Node kind
+
+// region Nodes
+
+/**
+ * Model a node in an XML document.
+ */
+class INode {
+ public:
+  /**
+   * @return the kind of the node, used instead of much slower RTTI.
+   */
+  virtual NodeKind kind() const = 0;
+  virtual ~INode() = default;
+};  // class INode
+
+/**
+ * Model the beginning of the input, before anything was read.
+ */
+class BofNode : public INode {
+ public:
+  NodeKind kind() const override { return NodeKind::Bof; }
+
+  ~BofNode() override = default;
+}; // class StartNode
+
+/**
+ * Model a start of an XML element.
+ */
+class StartNode : public INode {
+ public:
+  StartNode(
+    std::string a_name,
+    bool an_in_namespace
+  ) :
+    name(std::move(a_name)),
+    in_namespace(an_in_namespace) {
+    // Intentionally empty.
+  }
+
+  NodeKind kind() const override {
+    return in_namespace
+      ? NodeKind::Start
+      : NodeKind::StartInNoNamespace;
+  }
+
+  /**
+   * Name of the start element, stripped of the XML namespace
+   */
+  const std::string name;
+
+  /**
+   * True if the element resides in \ref kNamespace, and false if it resides
+   * in no namespace at all
+   */
+  const bool in_namespace;
+
+  ~StartNode() override = default;
+};  // class StartNode
+
+/**
+ * Model a stop of an XML element.
+ */
+class StopNode : public INode {
+ public:
+  StopNode(
+    std::string a_name,
+    bool an_in_namespace
+  ) :
+    name(std::move(a_name)),
+    in_namespace(an_in_namespace) {
+    // Intentionally empty.
+  }
+
+  NodeKind kind() const override {
+    return in_namespace
+      ? NodeKind::Stop
+      : NodeKind::StopInNoNamespace;
+  }
+
+  /**
+   * Name of the stop element, stripped of the XML namespace
+   */
+  const std::string name;
+
+  /**
+   * True if the element resides in \ref kNamespace, and false if it resides
+   * in no namespace at all
+   */
+  const bool in_namespace;
+
+  ~StopNode() override = default;
+};  // class StopNode
+
+/**
+ * Model a text node.
+ */
+class TextNode : public INode {
+ public:
+  explicit TextNode(
+    std::string a_text
+  ) :
+    text(std::move(a_text)) {
+    // Intentionally empty.
+  }
+
+  NodeKind kind() const override { return NodeKind::Text; }
+
+  /**
+   * UTF-8 encoded XML text somewhere within an XML element
+   */
+  const std::string text;
+
+  ~TextNode() override = default;
+};  // class TextNode
+
+/**
+ * Model an end-of-input.
+ */
+class EofNode : public INode {
+ public:
+  NodeKind kind() const override { return NodeKind::Eof; }
+
+  ~EofNode() override = default;
+};  // class EofNode
+
+/**
+ * Model a low-level XML parsing error.
+ */
+class ErrorNode : public INode {
+ public:
+  ErrorNode(
+    size_t a_line,
+    size_t a_column,
+    std::string a_cause
+  ) :
+    line(a_line),
+    column(a_column),
+    cause(std::move(a_cause)) {
+    // Intentionally empty.
+  }
+
+  NodeKind kind() const override { return NodeKind::Error; }
+
+  const size_t line;
+  const size_t column;
+
+  // Cause of the error as UTF-8 encoded string
+  const std::string cause;
+
+  ~ErrorNode() override = default;
+};  // class ErrorNode
+
+// endregion Nodes
+
+/**
+ * Render the node in a human-readable form, meant for error messages.
+ */
+std::string NodeToHumanReadableString(const INode& node);
+
+/**
+ * Render the node in a human-readable form, meant for error messages.
+ */
+std::wstring NodeToHumanReadableWstring(const INode& node);
+
+/**
+ * Check that the given node is a stop node residing in \ref kNamespace and
+ * that its name corresponds to the expected name.
+ */
+bool IsStopNodeWithName(
+    const INode& node,
+    const std::string& expected_name
+);
+
+/**
+ * Check that the given node is a stop node residing in no namespace at all and
+ * that its name corresponds to the expected name.
+ */
+bool IsStopNodeWithNameInNoNamespace(
+    const INode& node,
+    const std::string& expected_name
+);
+
+// region XSD lexical forms
+
+/**
+ * \brief Normalize \p text the way `whiteSpace="collapse"` prescribes.
+ *
+ * Every atomic XSD type except a string, and every type derived from one by
+ * restriction, fixes `whiteSpace` to `collapse`, and a schema author can not
+ * change it. A tab, a line feed and a carriage return each become a space,
+ * a run of spaces becomes one space, and the leading and trailing spaces go.
+ * Only the result of that is a lexical representation to be matched.
+ *
+ * Mind that this strips only the whitespace *around* the value: a space
+ * within it survives as a single space, so `2  3` becomes `2 3`, which is
+ * still no number.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#rf-whiteSpace
+ */
+std::string CollapseWhitespace(const std::string& text);
+
+/**
+ * \brief Tell whether \p text is a numeral of the `xs:long` lexical space.
+ *
+ *     [-+]?[0-9]+
+ *
+ * The range is left to the parser, which refuses what does not fit
+ * a 64-bit integer.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#long
+ */
+bool MatchesXsLongNumeral(const std::string& text);
+
+/**
+ * \brief Tell whether \p text is a numeral of the `xs:double` lexical space.
+ *
+ * The three named literals -- `INF`, `-INF` and `NaN` -- are matched by
+ * the caller, so only the numeral is considered here:
+ *
+ *     (\+|-)? ( [0-9]+ (\.[0-9]*)? | \.[0-9]+ ) ([Ee](\+|-)?[0-9]+)?
+ *
+ * This is spelled out rather than left to `std::regex` so that no pattern has
+ * to be compiled, and rather than left to `std::stod` because that one reads
+ * far more than XSD admits.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#double
+ */
+bool MatchesXsDoubleNumeral(const std::string& text);
+
+/**
+ * \brief Tell whether \p text is a lexical form of `xs:base64Binary`.
+ *
+ * The whitespace is expected to be gone already. What is left has to match
+ * `(B64 B64 B64 B64)* ((B64 B64 B64 B64) | (B64 B64 B16 '=') | (B64 B04 '=='))?`
+ * -- a length which is a multiple of four, the alphabet and nothing else,
+ * an equals sign only at the very end, and, easily missed, a constrained
+ * character *before* the padding, as the bits which the padding drops have to
+ * be zero.
+ *
+ * The decoders do not agree on any of this, so every target does the same
+ * check of its own and refuses the same texts.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+ */
+bool MatchesXsBase64Binary(const std::string& text);
+
+/**
+ * \brief Drop every whitespace character of \p text.
+ *
+ * This is what `xs:base64Binary` needs: it allows whitespace between
+ * the characters and not only around them, so collapsing is not enough --
+ * the decoder accepts none of it.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+ */
+std::string RemoveWhitespace(const std::string& text);
+
+// endregion XSD lexical forms
+
+// region Reading
+
+// region class Reader
+
+// NOTE (mristin):
+// The full definition is given in the implementation file, and only forward-declared
+// here since it is passed around exclusively through ``std::unique_ptr``.
+struct OurData;
+
+/**
+ * \brief Read XML in form of nodes, whereas text nodes are fragmented.
+ *
+ * We need a more abstract approach since the Expat library is too low-level
+ * to parse complex models.
+ *
+ * Expat does not read the whole content of a text node in memory, but
+ * we need to process the whole text during the XML de-serialization. Hence,
+ * we keep on reading until we read the complete text. This has repercussions
+ * on memory usage, as the the text will be held in three copies(one copy in
+ * the Expat buffer, second copy in our internal buffer in which we
+ * incrementally feed in the fragments, and the third copy is the final merged
+ * text).
+ */
+class Reader {
+ public:
+  /**
+   * \param is stream to read the XML from
+   * \param additional_attributes if set, unexpected XML attributes are ignored
+   * instead of being reported as errors
+   * \param buffer_size size of the chunk to be read from \p is and passed to
+   * the underlying XML parser
+   *
+   * Every element is expected to reside either in \ref kNamespace or in no
+   * namespace at all -- the latter is how the XML-RPC subset, over which
+   * a JSON-able value is de/serialized, is written. An element in any other
+   * namespace is reported as an error. Which of the two an element is expected
+   * to reside in depends on the grammar, so the node says which one it was, and
+   * the caller decides.
+   */
+  Reader(
+    std::istream& is,
+    bool additional_attributes,
+    size_t buffer_size
+  );
+
+  /**
+   * Set up the reader for the XML parsing and read the first node.
+   */
+  void Initialize();
+
+  /**
+   * Read the next node in the document.
+   */
+  void Read();
+
+  /**
+   * @return the node which has been read last
+   */
+  const INode& node() const;
+
+  /**
+   * @return the node which has been read last moved out of this reader
+   */
+  std::unique_ptr<INode> moved_node();
+
+  ~Reader();
+
+ private:
+  const bool additional_attributes_;
+  const size_t buffer_size_;
+  std::istream& is_;
+
+  XML_Parser parser_;
+  std::unique_ptr<OurData> our_data_;
+
+  // Node buffer does not include the current node.
+  std::deque<std::unique_ptr<INode>> node_buffer_;
+
+  // Current node is never null.
+  std::unique_ptr<INode> current_;
+
+  // Set if the current node is end-of-input
+  bool eof_;
+
+  // Set if the current node is an error
+  bool error_;
+
+  void SetCurrentAndEofAndError(std::unique_ptr<INode> node);
+
+  // Re-usable buffer to keep a chunk of the data read from the input
+  std::vector<char> chunk_;
+};  // class Reader
+
+// endregion class Reader
+
+// region class ReaderMergingText
+
+/**
+ * \brief Read XML in forms of nodes, with text nodes read in whole.
+ *
+ * This is a reader on top of the \ref Reader which keeps the text fragments
+ * in the buffer. We need to process the text in whole during the XML
+ * de-serialization, so this buffering is necessary. However, this means that
+ * the text is kept in four copies (one partial copy in Expat buffer,
+ * another partial copy as fragmented text nodes in the underlying \ref Reader
+ * instance, yet another copy in the internal buffer of this instance, and
+ * finally the fourth copy as the merged complete text).
+ */
+class ReaderMergingText {
+ public:
+  ReaderMergingText(
+    std::istream& is,
+    bool additional_attributes,
+    size_t buffer_size
+  );
+
+  /**
+   * Set up the reader for the XML parsing and read the first node.
+   */
+  void Initialize();
+
+  /**
+   * Read the next node in the document.
+   */
+  void Read();
+
+  /**
+   * @return the node which has been read last
+   */
+  const INode& node() const;
+
+  /**
+   * @return set if the current node represents an error
+   */
+  bool error() const;
+
+  /**
+   * @return set if the current node represents an end-of-input
+   */
+  bool eof() const;
+
+ private:
+  bool initialized_;
+  Reader reader_;
+
+  std::unique_ptr<INode> current_;
+  std::unique_ptr<INode> look_ahead_;
+
+  // Assuming that the underlying reader points to a text node,
+  // read all the consecutive text nodes and set the look-ahead node
+  void ReadAndMergeAllTextAndSetLookahead();
+
+  bool error_;
+  bool eof_;
+  void SetCurrentAndEofAndError(
+    std::unique_ptr<INode> node
+  );
+};  // class ReaderMergingText
+
+// endregion class ReaderMergingText
+
+// endregion Reading
+
+// region Writing
+
+/**
+ * Represent an error caught by \ref SelfClosingWriter.
+ */
+struct SerializationError {
+  /**
+   * Human-readable description of the error
+   */
+  std::wstring cause;
+
+  /**
+   * Path to the value that caused the error
+   */
+  iteration::Path path;
+
+  explicit SerializationError(
+    std::wstring a_cause
+  );
+};  // struct SerializationError
+
+extern const std::wstring kTheOutputStreamIsInABadState;
+
+/**
+ * Check that the output stream is not in a bad state. If so, create an error.
+ */
+common::optional<SerializationError> CheckOstreamState(
+  const std::ostream& os
+);
+
+// region class SelfClosingWriter
+
+/**
+ * \brief Write XML elements, shortening an element with no content to
+ * a self-closing element.
+ */
+class SelfClosingWriter {
+ public:
+  /**
+   * \param os to write to
+   * \param root_attributes attributes of the outermost element, written
+   * verbatim and each preceded by a space; the declaration of \ref kNamespace,
+   * or nothing at all
+   */
+  SelfClosingWriter(
+    std::ostream& os,
+    const char* root_attributes
+  );
+
+  /**
+   * Queue a start element for an eventual write.
+   */
+  void StartElement(
+    std::string name
+  );
+
+  /**
+   * Write a stop element.
+   *
+   * If there is a pending start element with no content, shorten it to
+   * a self-closing XML element.
+   */
+  void StopElement(
+    const std::string& name
+  );
+
+  /**
+   * \brief Serialize the given boolean to an xs:bool value.
+   *
+   * We explicitly write longer text, `true` and `false`, to make the values explicit,
+   * and not potentially confusing with numbers, in the XML.
+   */
+  void SerializeBool(
+    bool value
+  );
+
+  /**
+   * \brief Serialize the given number to an xs:long value.
+   *
+   * We do not check that the number is within a range representable as 64-bit
+   * floats, as the value can be de-serialized correctly from XML. However, this
+   * means that XML and JSON serializations are not interoperable. If you need
+   * interoperability, you have to ensure that range yourself (<i>e.g.</i>, through
+   * \ref validation).
+   */
+  void SerializeInt64(
+    int64_t value
+  );
+
+  /**
+   * \brief Serialize the given number to an xs:double value.
+   */
+  void SerializeDouble(
+    double value
+  );
+
+  /**
+   * \brief Write the text while escaping special characters for XML.
+   */
+  void SerializeWstring(
+    const std::wstring& text
+  );
+
+  /**
+   * \brief Write the text while escaping special characters for XML.
+   */
+  void SerializeString(
+    const std::string& text
+  );
+
+  /**
+   * \brief Encode bytes to Base64 and write them.
+   */
+  void SerializeByteArray(
+  const std::vector<std::uint8_t>& byte_array
+  );
+
+  /**
+   * Finish and flush any pending start nodes.
+   */
+  void Finish();
+
+  /**
+   * Get an error, if any, caught during the serialization.
+   */
+  const common::optional<SerializationError>& error() const;
+
+  /**
+   * Transfer the ownership of the error.
+   */
+  common::optional<SerializationError>&& move_error();
+
+ private:
+  std::ostream& os_;
+  common::optional<SerializationError> error_;
+  common::optional<std::string> pending_start_wo_text_;
+
+  /**
+   * \brief Attributes of the outermost element, until it has been queued.
+   *
+   * The very first \ref StartElement takes them and leaves nothing behind, so
+   * that the namespace is declared on the root element and on no other.
+   */
+  const char* root_attributes_;
+
+  /**
+   * Attributes of the pending start element; the declaration of the namespace
+   * for the outermost element, its undeclaration for the outermost element
+   * which resides in no namespace, and nothing otherwise
+   */
+  const char* pending_attributes_;
+
+  /**
+   * \brief Escape the given text to XML.
+   *
+   * Return nothing if no escaping was needed.
+   */
+  static common::optional<std::wstring> EscapeForXml(
+    const std::wstring& text
+  );
+
+  /**
+   * \brief Escape the given text to XML.
+   *
+   * Return nothing if no escaping was needed.
+   */
+  static common::optional<std::string> EscapeForXml(
+    const std::string& text
+  );
+
+  void WritePendingStartElementIfAvailable();
+
+  /**
+   * Write the text without any XML escaping or flushing of pending start elements.
+   */
+  void WriteStringWithoutEscapingNorFlushing(
+    const std::string& text
+  );
+};  // class SelfClosingWriter
+
+// endregion class SelfClosingWriter
+
+// endregion Writing
+
+}  // namespace xml_common
+
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#endif  // DUMMY_XML_COMMON_GUARD_
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_path.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_path.cpp
new file mode 100644
index 000000000..e6da8cd36
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xml_path.cpp
@@ -0,0 +1,239 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/xml_path.hpp"
+
+#pragma warning(push, 0)
+#include <string>
+#include <utility>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+namespace xml_path {
+
+namespace {
+
+/**
+ * \brief Escape \p text so that it can be directly inserted into an XPath.
+ *
+ * \param text to be escaped
+ * \return the escaped text
+ */
+std::wstring EscapeForXPath(
+  const std::wstring& text
+) {
+  size_t out_len = 0;
+  for (const wchar_t character : text) {
+    switch (character) {
+      // NOTE (mristin):
+      // We use sizeof on *strings* instead of *wide strings* to get
+      // the number of *characters*. Otherwise, if we used wide strings,
+      // we would obtain the wrong number of characters with `sizeof`
+      // as we would count bytes instead of characters, which differ
+      // in wide strings due to encoding.
+
+      case L'&': {
+        out_len += sizeof("&amp;");
+        break;
+      }
+      case L'/': {
+        out_len += sizeof("&#47;");
+        break;
+      }
+      case L'<': {
+        out_len += sizeof("&lt;");
+        break;
+      }
+      case L'>': {
+        out_len += sizeof("&gt;");
+        break;
+      }
+      case L'"': {
+        out_len += sizeof("&quot;");
+        break;
+      }
+      case L'\'': {
+        out_len += sizeof("&apos;");
+        break;
+      }
+      default:
+        ++out_len;
+        break;
+    }
+  }
+
+  // NOTE (mristin):
+  // We assume here that XML encoding is always *longer* than
+  // the original text.
+  if (out_len == text.size()) {
+    return text;
+  }
+
+  std::wstring out;
+  out.reserve(out_len);
+
+  for (const wchar_t character : text) {
+    switch (character) {
+      case L'&':
+        out.append(L"&amp;");
+        break;
+      case L'/':
+        out.append(L"&#47;");
+        break;
+      case L'<':
+        out.append(L"&lt;");
+        break;
+      case L'>':
+        out.append(L"&gt;");
+        break;
+      case L'"':
+        out.append(L"&quot;");
+        break;
+      case L'\'':
+        out.append(L"&apos;");
+        break;
+      default:
+        out.push_back(character);
+        break;
+    }
+  }
+
+  return out;
+}
+
+}  // namespace
+
+// region struct ElementSegment
+
+ElementSegment::ElementSegment(
+  std::wstring a_name
+) :
+  name(std::move(a_name)) {
+  // Intentionally empty.
+}
+
+std::wstring ElementSegment::ToWstring() const {
+  return EscapeForXPath(name);
+}
+
+std::unique_ptr<ISegment> ElementSegment::Clone() const {
+  return common::make_unique<ElementSegment>(*this);
+}
+
+// endregion struct ElementSegment
+
+// region struct MemberSegment
+
+MemberSegment::MemberSegment(
+  std::wstring a_name
+) :
+  name(std::move(a_name)) {
+  // Intentionally empty.
+}
+
+std::wstring MemberSegment::ToWstring() const {
+  return common::Concat(
+    L"member[name=\"",
+    EscapeForXPath(name),
+    L"\"]"
+  );
+}
+
+std::unique_ptr<ISegment> MemberSegment::Clone() const {
+  return common::make_unique<MemberSegment>(*this);
+}
+
+// endregion struct MemberSegment
+
+// region struct IndexSegment
+
+IndexSegment::IndexSegment(
+  size_t an_index
+) :
+  index(an_index) {
+  // Intentionally empty.
+}
+
+std::wstring IndexSegment::ToWstring() const {
+  return common::Concat(
+    L"*[",
+    std::to_wstring(index + 1),
+    L"]"
+  );
+}
+
+std::unique_ptr<ISegment> IndexSegment::Clone() const {
+  return common::make_unique<IndexSegment>(*this);
+}
+
+// endregion struct IndexSegment
+
+// region struct Path
+
+Path::Path() {
+  // Intentionally empty.
+}
+
+Path::Path(const Path& other) {
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+}
+
+Path::Path(Path&& other) {
+  segments = std::move(other.segments);
+}
+
+Path& Path::operator=(const Path& other) {
+  segments.clear();
+  for (const std::unique_ptr<ISegment>& segment : other.segments) {
+    segments.emplace_back(segment->Clone());
+  }
+  return *this;
+}
+
+Path& Path::operator=(Path&& other) {
+  if (this != &other) {
+    segments = std::move(other.segments);
+  }
+  return *this;
+}
+
+std::wstring Path::ToWstring() const {
+  if (segments.empty()) {
+    return L"";
+  }
+
+  std::vector<std::wstring> parts;
+  parts.reserve(segments.size() * 2 - 1);
+
+  auto it = segments.begin();
+
+  parts.emplace_back((*it)->ToWstring());
+  ++it;
+
+  for (; it != segments.end(); ++it) {
+    parts.emplace_back(L"/");
+    parts.emplace_back((*it)->ToWstring());
+  }
+
+  size_t out_len = 0;
+  for (const std::wstring& part : parts) {
+    out_len += part.size();
+  }
+
+  std::wstring out;
+  out.reserve(out_len);
+  for (const std::wstring& part : parts) {
+    out.append(part);
+  }
+
+  return out;
+}
+
+}  // namespace xml_path
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xmlization.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xmlization.cpp
new file mode 100644
index 000000000..92ee9b02e
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/src/xmlization.cpp
@@ -0,0 +1,3185 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/stringification.hpp"
+#include "dummy/wstringification.hpp"
+#include "dummy/xmlization.hpp"
+
+#include "xml_common.hpp"
+
+#pragma warning(push, 0)
+#include <bitset>
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
+#include <deque>
+#include <memory>
+#include <limits>
+#include <unordered_map>
+#include <string>
+#include <vector>
+#pragma warning(pop)
+
+namespace dummy {
+namespace xmlization {
+
+const std::string kNamespace(  // NOLINT(cert-err58-cpp)
+  xml_common::kNamespace
+);
+
+// region De-serialization
+
+// region DeserializationError
+
+DeserializationError::DeserializationError(
+  std::wstring a_cause
+) :
+  cause(a_cause) {
+  // Intentionally empty.
+}
+
+DeserializationError::DeserializationError(
+  std::wstring a_cause,
+  xml_path::Path a_path
+) :
+  cause(a_cause),
+  path(a_path) {
+  // Intentionally empty.
+}
+
+// endregion DeserializationError
+
+// region Forward declarations of de-serialization functions
+
+// NOTE (mristin):
+// We make forward declarations of de-serialization functions so that they can be
+// called in any order.
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IItem>
+  >,
+  common::optional<DeserializationError>
+> ItemFromElement(
+  xml_common::ReaderMergingText& reader
+);
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISomeItem>
+  >,
+  common::optional<DeserializationError>
+> SomeItemFromElement(
+  xml_common::ReaderMergingText& reader
+);
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISomeItem>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> SomeItemFromSequence(
+  xml_common::ReaderMergingText& reader
+);
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISpecialItem>
+  >,
+  common::optional<DeserializationError>
+> SpecialItemFromElement(
+  xml_common::ReaderMergingText& reader
+);
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> SpecialItemFromSequence(
+  xml_common::ReaderMergingText& reader
+);
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> ContainerFromElement(
+  xml_common::ReaderMergingText& reader
+);
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::IContainer>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ContainerFromSequence(
+  xml_common::ReaderMergingText& reader
+);
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> WrapperFromElement(
+  xml_common::ReaderMergingText& reader
+);
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::IWrapper>::value
+  >::type* = nullptr
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> WrapperFromSequence(
+  xml_common::ReaderMergingText& reader
+);
+
+// endregion Forward declarations of de-serialization functions
+
+/**
+ * Map XML class names to model types.
+ */
+const std::unordered_map<
+  std::string,
+  types::ModelType
+> kElementNameToModelType = {
+  {
+    "someItem",
+    types::ModelType::kSomeItem
+  },
+  {
+    "specialItem",
+    types::ModelType::kSpecialItem
+  },
+  {
+    "container",
+    types::ModelType::kContainer
+  },
+  {
+    "wrapper",
+    types::ModelType::kWrapper
+  }
+};
+
+common::optional<types::ModelType> ModelTypeFromElementName(
+  const std::string& element_name
+) {
+  auto it = kElementNameToModelType.find(element_name);
+  if (it == kElementNameToModelType.end()) {
+    return common::nullopt;
+  }
+
+  return it->second;
+}
+
+template <
+  typename T
+>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> InstanceAndNoDeserializationError(
+  T&& instance
+) {
+  return std::make_pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >(
+    std::move(instance),
+    common::nullopt
+  );
+}
+
+template <
+  typename T
+> std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> NoInstanceAndDeserializationErrorWithCause(
+  std::wstring cause
+) {
+  return std::make_pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >(
+    common::nullopt,
+    common::make_optional<DeserializationError>(
+      std::move(cause)
+    )
+  );
+}
+
+DeserializationError DuplicatePropertyError(
+  const std::string& name
+) {
+  return DeserializationError(
+    common::Concat(
+      L"Property ",
+      common::Utf8ToWstring(name),
+      L" occurred more than once"
+    )
+  );
+}
+
+DeserializationError DeserializationErrorFromReader(
+  xml_common::ReaderMergingText& reader
+) {
+  if (reader.node().kind() != xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      common::Concat(
+        "Expected an error node at the reader cursor, but got ",
+        xml_common::NodeToHumanReadableString(reader.node())
+      )
+    );
+  }
+
+  const auto error_node(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const xml_common::ErrorNode&
+    >(reader.node())
+  );
+
+  return DeserializationError(
+    common::Utf8ToWstring(
+      error_node.cause
+    )
+  );
+}
+
+template <
+  typename T
+>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> NoInstanceAndDeserializationErrorFromReader(
+  xml_common::ReaderMergingText& reader
+) {
+  if (reader.node().kind() != xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      common::Concat(
+        "Expected an error node at the reader cursor, but got ",
+        xml_common::NodeToHumanReadableString(reader.node())
+      )
+    );
+  }
+
+  DeserializationError error = DeserializationErrorFromReader(
+    reader
+  );
+
+  return std::make_pair(
+    common::nullopt,
+    common::make_optional<DeserializationError>(
+      std::move(error)
+    )
+  );
+}
+
+template <
+  typename T
+>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> NoInstanceAndDeserializationError(
+  DeserializationError error
+) {
+  return std::make_pair(
+    common::nullopt,
+    common::make_optional<DeserializationError>(
+      std::move(error)
+    )
+  );
+}
+
+void PrependElementSegmentToDeserializationError(
+  const std::string& name,
+  DeserializationError& deserialization_error
+) {
+  deserialization_error.path.segments.emplace_front(
+    common::make_unique<xml_path::ElementSegment>(
+      common::Utf8ToWstring(name)
+    )
+  );
+}
+
+common::optional<DeserializationError> CheckReaderAtEof(
+  const xml_common::ReaderMergingText& reader
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in CheckReaderAtEof. "
+      "CheckReaderAtEof expects no reader error at entry."
+    );
+  }
+  #endif
+
+  if (reader.node().kind() != xml_common::NodeKind::Eof) {
+    return common::make_optional<DeserializationError>(
+      common::Concat(
+        L"Expected end-of-input, but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Skip the beginning-of-file (BoF) and read a node.
+ *
+ * Do nothing if the cursor points to a non-BoF node.
+ *
+ * Return an error if the reader produced an error.
+ */
+common::optional<DeserializationError> SkipBof(
+  xml_common::ReaderMergingText& reader
+) {
+  if (reader.node().kind() != xml_common::NodeKind::Bof) {
+    return common::nullopt;
+  }
+
+  reader.Read();
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return DeserializationErrorFromReader(reader);
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * Return `true` if all characters are whitespace in the UTF-8-encoded text.
+ */
+bool IsWhitespace(const std::string& utf8_text) {
+  for (const char character : utf8_text) {
+    switch (character) {
+      // NOTE (mristin):
+      // The characters are ordered by their ASCII codes so that
+      // we allow compilers to optimize.
+
+      // NOTE (mristin):
+      // Text nodes contain text in UTF-8 which is compatible with ASCII.
+      // In particular, all characters above ASCII (>127) are encoded with
+      // all the leading bits set. Hence, it is safe to check for whitespace
+      // characters in an UTF-8-encoded string using one-byte characters.
+      //
+      // See: https://stackoverflow.com/questions/15965811/why-utf8-is-compatible-with-ascii
+
+      case '\t':
+      case '\n':
+      case '\r':
+      case ' ':
+        // Pass
+        break;
+      default:
+        return false;
+    }
+  }
+
+  return true;
+}
+
+/**
+ * \brief Skip all whitespace text nodes.
+ *
+ * Do nothing if the cursor points to a non-text node.
+ *
+ * The whitespace includes space, tab, carriage return and newline.
+ *
+ * Return an error if the reader produced an error.
+ */
+common::optional<DeserializationError> SkipWhitespace(
+  xml_common::ReaderMergingText& reader
+) {
+  while (reader.node().kind() == xml_common::NodeKind::Text) {
+    const xml_common::TextNode& text_node(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::TextNode&
+      >(
+        reader.node()
+      )
+    );
+
+    if (!IsWhitespace(text_node.text)) {
+      break;
+    }
+
+    reader.Read();
+  }
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return DeserializationErrorFromReader(reader);
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Create the exception to be thrown on an unexpected property literal.
+ *
+ * Every ``switch`` over the properties of a class covers all the literals of
+ * its enumeration, so we can only get here if the value has been corrupted.
+ * We report that as a logic error, and not as a de-serialization error, since
+ * it does not originate in the input.
+ *
+ * \param enum_name name of the property enumeration, for the message
+ * \param property the unexpected literal
+ * \return the exception to be thrown
+ */
+template <typename EnumT>
+std::logic_error UnexpectedPropertyLiteralError(
+  const char* enum_name,
+  EnumT property
+) {
+  return std::logic_error(
+    common::Concat(
+      "Unexpected properties literal of ",
+      enum_name,
+      ": ",
+      std::to_string(
+        static_cast<std::uint32_t>(property)
+      )
+    )
+  );
+}
+
+/**
+ * \brief Read the properties of an instance as a sequence of XML elements.
+ *
+ * The cursor is expected to point at the content of the element which opens
+ * the instance. On success, the cursor points at the stop element closing it,
+ * which the caller is expected to consume.
+ *
+ * This function factors out everything which the property loop of a class does
+ * not say about the class it belongs to: skipping the whitespace, recognizing
+ * the end of the sequence, reading and consuming the start element, looking
+ * the property up, refusing a duplicate, marking the property on the error path
+ * and consuming the stop element. The class itself supplies only \p on_property,
+ * which dispatches on the property and assigns the local variables that its
+ * constructor is finally called with.
+ *
+ * NOTE (mristin):
+ * We take \p map_of_properties in, instead of letting \p on_property work on
+ * the XML name of the property, because we want the class to dispatch with
+ * a hard-wired ``switch`` whose branches assign the local variables of
+ * the caller.
+ *
+ * A ``switch`` needs an integral constant, and C++ can not switch on a string,
+ * so the name has to be translated into a literal of the property enumeration
+ * first. We do that here rather than in the class so that the translation, and
+ * the error reported when the name matches no property at all, are written
+ * once instead of once per class.
+ *
+ * The alternative -- mapping the name directly to the code which reads
+ * the property -- would cost a type-erased, capturing callable per property,
+ * built anew on every single read, since the code has to assign the caller's
+ * variables. The ``switch`` costs a jump table.
+ *
+ * \tparam kPropertyCount number of the properties of the class
+ * \param reader to read from
+ * \param map_of_properties maps the XML name of a property to its literal
+ * \param interface_name name of the interface, for the messages
+ * \param on_property reads the content of the recognized property
+ * \return the error, if the reading failed
+ */
+template <std::size_t kPropertyCount, typename EnumT, typename OnPropertyT>
+common::optional<DeserializationError> ReadProperties(
+  xml_common::ReaderMergingText& reader,
+  const std::unordered_map<std::string, EnumT>& map_of_properties,
+  const wchar_t* interface_name,
+  const OnPropertyT& on_property
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in ReadProperties. "
+      "ReadProperties expects no reader error at entry."
+    );
+  }
+  #endif
+
+  common::optional<DeserializationError> error;
+
+  error = SkipBof(reader);
+  if (error.has_value()) {
+    return error;
+  }
+
+  // NOTE (mristin):
+  // Whether a property has already occurred is a bookkeeping of this loop, and
+  // not of the property, so we track it here, indexed by the property literal,
+  // instead of asking every single target variable at every single case of
+  // the ``switch``.
+  //
+  // The bit set is sized to the class, so a class may have arbitrarily many
+  // properties, and it lives on the stack, so nothing is allocated for it on
+  // a read.
+  std::bitset<kPropertyCount> seen;
+
+  while (true) {
+    error = SkipWhitespace(reader);
+    if (error.has_value()) {
+      return error;
+    }
+
+    if (reader.node().kind() == xml_common::NodeKind::Stop) {
+      // NOTE (mristin):
+      // We reached a closing element of an instance, so we know that
+      // the sequence ended.
+      return common::nullopt;
+    } else if (reader.node().kind() != xml_common::NodeKind::Start) {
+      return DeserializationError(
+        common::Concat(
+          L"Expected a start element opening a property of ",
+          interface_name,
+          L", but got ",
+          xml_common::NodeToHumanReadableWstring(reader.node())
+        )
+      );
+    }
+
+    const std::string name(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::StartNode&
+      >(reader.node()).name
+    );
+
+    // NOTE (mristin):
+    // We consume the start element.
+    reader.Read();
+
+    if (reader.node().kind() == xml_common::NodeKind::Error) {
+      error = DeserializationErrorFromReader(reader);
+
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+
+    auto it = map_of_properties.find(name);
+    if (it == map_of_properties.end()) {
+      return DeserializationError(
+        common::Concat(
+          L"Expected a start element opening a property of ",
+          interface_name,
+          L", but got a start element "
+          L"which does not correspond to any of its properties: <",
+          common::Utf8ToWstring(name),
+          L">"
+        )
+      );
+    }
+
+    const EnumT property(it->second);
+
+    // NOTE (mristin):
+    // The literals of a property enumeration run from zero without a gap, and
+    // the map maps only to them, so the index is always in the range of
+    // the bit set. We check that only in debug builds, and index unchecked
+    // otherwise.
+    const std::size_t index(
+      static_cast<std::size_t>(property)
+    );
+
+    #ifdef DEBUG
+    if (index >= kPropertyCount) {
+      throw std::logic_error(
+        common::Concat(
+          "Unexpected property index in ReadProperties: ",
+          std::to_string(index),
+          ", but there are only ",
+          std::to_string(kPropertyCount),
+          " properties"
+        )
+      );
+    }
+    #endif
+
+    // NOTE (mristin):
+    // An engaged bit can only have been set by an earlier turn of this loop, so
+    // it tells us that the property comes a second time. The check precedes
+    // the read, so the duplicate is refused without its content ever being
+    // looked at.
+    if (seen[index]) {
+      error = DuplicatePropertyError(name);
+
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+
+    seen[index] = true;
+
+    error = on_property(property);
+    if (error.has_value()) {
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+
+    error = SkipWhitespace(reader);
+    if (error.has_value()) {
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+
+    if (!xml_common::IsStopNodeWithName(reader.node(), name)) {
+      error = DeserializationError(
+        common::Concat(
+          L"Expected a stop element </",
+          common::Utf8ToWstring(name),
+          L"> closing the property of ",
+          interface_name,
+          L", but got ",
+          xml_common::NodeToHumanReadableWstring(reader.node())
+        )
+      );
+
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+
+    // NOTE (mristin):
+    // We consume the stop element.
+    reader.Read();
+
+    if (reader.node().kind() == xml_common::NodeKind::Error) {
+      error = DeserializationErrorFromReader(reader);
+
+      PrependElementSegmentToDeserializationError(
+        name,
+        *error
+      );
+
+      return error;
+    }
+  }
+}
+
+template <typename ValueT, typename DispatchT>
+std::pair<
+  common::optional<ValueT>,
+  common::optional<DeserializationError>
+> DeserializeFromElement(
+  xml_common::ReaderMergingText& reader,
+  const wchar_t* value_name,
+  const DispatchT& dispatch
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeFromElement. "
+      "DeserializeFromElement expects no reader error at entry."
+    );
+  }
+  #endif
+
+  common::optional<DeserializationError> error;
+
+  error = SkipBof(reader);
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  error = SkipWhitespace(reader);
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  if (reader.node().kind() != xml_common::NodeKind::Start) {
+    return NoInstanceAndDeserializationErrorWithCause<ValueT>(
+      common::Concat(
+        L"Expected a start element opening an instance of ",
+        value_name,
+        L", but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+  }
+
+  const std::string name(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const xml_common::StartNode&
+    >(reader.node()).name
+  );
+
+  common::optional<types::ModelType> model_type(
+    ModelTypeFromElementName(name)
+  );
+  if (!model_type.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<ValueT>(
+      common::Concat(
+        L"Unexpected start element as its name does not correspond "
+        L"to any model type: ",
+        common::Utf8ToWstring(name)
+      )
+    );
+  }
+
+  // NOTE (mristin):
+  // We consume the start element.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<ValueT>(reader);
+  }
+
+  common::optional<ValueT> instance;
+  std::tie(
+    instance,
+    error
+  ) = dispatch(reader, *model_type, name);
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  error = SkipWhitespace(reader);
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  if (!xml_common::IsStopNodeWithName(reader.node(), name)) {
+    error = DeserializationError(
+      common::Concat(
+        L"Expected a stop element </",
+        common::Utf8ToWstring(name),
+        L"> closing an instance of ",
+        value_name,
+        L", but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  // NOTE (mristin):
+  // We consume the stop element.
+  reader.Read();
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    error = DeserializationErrorFromReader(reader);
+    return NoInstanceAndDeserializationError<ValueT>(std::move(*error));
+  }
+
+  return InstanceAndNoDeserializationError(
+    std::move(*instance)
+  );
+}
+
+template <typename ValueT>
+std::pair<
+  common::optional<ValueT>,
+  common::optional<DeserializationError>
+> DeserializeSoleFromElement(
+  xml_common::ReaderMergingText& reader,
+  const wchar_t* value_name,
+  types::ModelType expected_model_type,
+  std::pair<
+    common::optional<ValueT>,
+    common::optional<DeserializationError>
+  > (*from_sequence)(xml_common::ReaderMergingText&)
+) {
+  return DeserializeFromElement<ValueT>(
+    reader,
+    value_name,
+    [value_name, expected_model_type, from_sequence](
+      xml_common::ReaderMergingText& a_reader,
+      types::ModelType a_model_type,
+      const std::string& a_name
+    ) -> std::pair<
+      common::optional<ValueT>,
+      common::optional<DeserializationError>
+    > {
+      if (a_model_type != expected_model_type) {
+        return NoInstanceAndDeserializationErrorWithCause<ValueT>(
+          common::Concat(
+            L"Impossible to de-serialize an instance of ",
+            value_name,
+            L" from <",
+            common::Utf8ToWstring(a_name),
+            L">"
+          )
+        );
+      }
+
+      return from_sequence(a_reader);
+    }
+  );
+}
+
+/**
+ * \brief De-serialize a value from the element nested in another element, such
+ * as the instance in a property, or from the root element.
+ *
+ * We prepend the name of the nested element to the path of an error, so that
+ * the path reads, *e.g.*, <code>value/property/idShort</code>.
+ *
+ * This looks redundant next to reading an item of a list, and it is not.
+ * An item is not nested in an element of its own -- the item element *is*
+ * the indexed child -- so its readers prepend only the index, and the path
+ * reads, *e.g.*, <code>annotations/&#42;[1]/idShort</code>.
+ *
+ * \param reader to read from
+ * \param deserialize_element de-serializes the nested element
+ * \return the value, or an error, if any
+ */
+template <typename T, typename DeserializeT>
+std::pair<
+  common::optional<T>,
+  common::optional<DeserializationError>
+> DeserializeNestedElement(
+  xml_common::ReaderMergingText& reader,
+  const DeserializeT& deserialize_element
+) {
+  common::optional<DeserializationError> error = SkipWhitespace(reader);
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<T>(std::move(*error));
+  }
+
+  if (reader.node().kind() != xml_common::NodeKind::Start) {
+    return deserialize_element(reader);
+  }
+
+  const std::string name(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const xml_common::StartNode&
+    >(reader.node()).name
+  );
+
+  std::pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  > result = deserialize_element(reader);
+
+  if (result.second.has_value()) {
+    PrependElementSegmentToDeserializationError(
+      name,
+      *(result.second)
+    );
+  }
+
+  return result;
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IClass>
+  >,
+  common::optional<DeserializationError>
+> ClassFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeFromElement<
+    std::shared_ptr<types::IClass>
+  >(
+    reader,
+    L"IClass",
+    [](
+      xml_common::ReaderMergingText& a_reader,
+      types::ModelType a_model_type,
+      const std::string& a_name
+    ) -> std::pair<
+      common::optional<std::shared_ptr<types::IClass> >,
+      common::optional<DeserializationError>
+    > {
+      switch (a_model_type) {
+        case types::ModelType::kSomeItem:
+          return SomeItemFromSequence<
+            types::IClass
+          >(a_reader);
+        case types::ModelType::kSpecialItem:
+          return SpecialItemFromSequence<
+            types::IClass
+          >(a_reader);
+        case types::ModelType::kContainer:
+          return ContainerFromSequence<
+            types::IClass
+          >(a_reader);
+        case types::ModelType::kWrapper:
+          return WrapperFromSequence<
+            types::IClass
+          >(a_reader);
+        default:
+          return NoInstanceAndDeserializationErrorWithCause<
+            std::shared_ptr<types::IClass>
+          >(
+            common::Concat(
+              L"Impossible to de-serialize an instance "
+              L"of IClass from <",
+              common::Utf8ToWstring(a_name),
+              L">"
+            )
+          );
+      }
+    }
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IItem>
+  >,
+  common::optional<DeserializationError>
+> ItemFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeFromElement<
+    std::shared_ptr<types::IItem>
+  >(
+    reader,
+    L"IItem",
+    [](
+      xml_common::ReaderMergingText& a_reader,
+      types::ModelType a_model_type,
+      const std::string& a_name
+    ) -> std::pair<
+      common::optional<std::shared_ptr<types::IItem> >,
+      common::optional<DeserializationError>
+    > {
+      switch (a_model_type) {
+        case types::ModelType::kSomeItem:
+          return SomeItemFromSequence<
+            types::IItem
+          >(a_reader);
+        case types::ModelType::kSpecialItem:
+          return SpecialItemFromSequence<
+            types::IItem
+          >(a_reader);
+        default:
+          return NoInstanceAndDeserializationErrorWithCause<
+            std::shared_ptr<types::IItem>
+          >(
+            common::Concat(
+              L"Impossible to de-serialize an instance "
+              L"of IItem from <",
+              common::Utf8ToWstring(a_name),
+              L">"
+            )
+          );
+      }
+    }
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISomeItem>
+  >,
+  common::optional<DeserializationError>
+> SomeItemFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeFromElement<
+    std::shared_ptr<types::ISomeItem>
+  >(
+    reader,
+    L"ISomeItem",
+    [](
+      xml_common::ReaderMergingText& a_reader,
+      types::ModelType a_model_type,
+      const std::string& a_name
+    ) -> std::pair<
+      common::optional<std::shared_ptr<types::ISomeItem> >,
+      common::optional<DeserializationError>
+    > {
+      switch (a_model_type) {
+        case types::ModelType::kSomeItem:
+          return SomeItemFromSequence<
+            types::ISomeItem
+          >(a_reader);
+        case types::ModelType::kSpecialItem:
+          return SpecialItemFromSequence<
+            types::ISomeItem
+          >(a_reader);
+        default:
+          return NoInstanceAndDeserializationErrorWithCause<
+            std::shared_ptr<types::ISomeItem>
+          >(
+            common::Concat(
+              L"Impossible to de-serialize an instance "
+              L"of ISomeItem from <",
+              common::Utf8ToWstring(a_name),
+              L">"
+            )
+          );
+      }
+    }
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::ISpecialItem>
+  >,
+  common::optional<DeserializationError>
+> SpecialItemFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeSoleFromElement<
+    std::shared_ptr<types::ISpecialItem>
+  >(
+    reader,
+    L"ISpecialItem",
+    types::ModelType::kSpecialItem,
+    SpecialItemFromSequence<types::ISpecialItem>
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IContainer>
+  >,
+  common::optional<DeserializationError>
+> ContainerFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeSoleFromElement<
+    std::shared_ptr<types::IContainer>
+  >(
+    reader,
+    L"IContainer",
+    types::ModelType::kContainer,
+    ContainerFromSequence<types::IContainer>
+  );
+}
+
+std::pair<
+  common::optional<
+    std::shared_ptr<types::IWrapper>
+  >,
+  common::optional<DeserializationError>
+> WrapperFromElement(
+  xml_common::ReaderMergingText& reader
+) {
+  return DeserializeSoleFromElement<
+    std::shared_ptr<types::IWrapper>
+  >(
+    reader,
+    L"IWrapper",
+    types::ModelType::kWrapper,
+    WrapperFromSequence<types::IWrapper>
+  );
+}
+
+// region De-serialize primitives
+
+const std::unordered_map<
+  std::string,
+  bool
+> kTextToBool = {
+  {"true", true},
+  {"false", false},
+  {"1", true},
+  {"0", false}
+};
+
+std::pair<
+  common::optional<bool>,
+  common::optional<DeserializationError>
+> DeserializeBool(
+  xml_common::ReaderMergingText& reader
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeBool. "
+      "DeserializeBool expects no error node."
+    );
+  }
+  #endif
+
+  if (reader.node().kind() != xml_common::NodeKind::Text) {
+    return NoInstanceAndDeserializationErrorWithCause<bool>(
+      common::Concat(
+        L"Expected to parse an xs:boolean from XML text, but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+  }
+
+  const std::string text(
+    xml_common::CollapseWhitespace(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::TextNode&
+      >(reader.node()).text
+    )
+  );
+
+  auto it = kTextToBool.find(text);
+  if (it == kTextToBool.end()) {
+    return NoInstanceAndDeserializationErrorWithCause<bool>(
+      common::Concat(
+        L"Expected to parse an xs:boolean from text, "
+        L"but got an invalid value: ",
+        common::Utf8ToWstring(text)
+      )
+    );
+  }
+
+  // NOTE (mristin):
+  // We consume the text node.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<bool>(reader);
+  }
+
+  return std::make_pair(
+    it->second,
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<int64_t>,
+  common::optional<DeserializationError>
+> DeserializeInt64(
+  xml_common::ReaderMergingText& reader
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeInt64. "
+      "DeserializeInt64 expects no error node."
+    );
+  }
+  #endif
+
+  if (reader.node().kind() != xml_common::NodeKind::Text) {
+    return NoInstanceAndDeserializationErrorWithCause<int64_t>(
+      common::Concat(
+        L"Expected to parse an xs:long from XML text, but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+  }
+
+  const std::string text(
+    xml_common::CollapseWhitespace(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::TextNode&
+      >(reader.node()).text
+    )
+  );
+
+  // NOTE (mristin):
+  // The lexical form has to be checked before the text is parsed. The std::sto*
+  // family reads far more than XSD admits: it stops at the first character it
+  // can not use and answers with what it has read so far, so "0x10" comes out
+  // as 0, "1abc" as 1, and "5.0" as 5.
+  if (!xml_common::MatchesXsLongNumeral(text)) {
+    return NoInstanceAndDeserializationErrorWithCause<int64_t>(
+      common::Concat(
+        L"Expected to parse an xs:long from text, "
+        L"but got an invalid value: ",
+        common::Utf8ToWstring(text)
+      )
+    );
+  }
+
+  common::optional<int64_t> deserialized;
+
+  static_assert(
+    sizeof(int) == 8
+    || sizeof(long) == 8
+    || sizeof(long long) == 8,
+    "Neither int nor long nor long long are 8 bytes long, "
+    "so we do not know how to parse an xs:long."
+  );
+
+  try {
+    // NOTE (mristin):
+    // We remove the warning C4101 in MSVC with constants.
+    // See: https://stackoverflow.com/questions/25573996/c4127-conditional-expression-is-constant
+    const bool sizeof_int_is_8 = sizeof(int) == 8;
+    const bool sizeof_long_is_8 = sizeof(long) == 8;
+    const bool sizeof_long_long_is_8 = sizeof(long long) == 8;
+
+    if (sizeof_int_is_8) {
+      deserialized = std::stoi(text);
+    } else if (sizeof_long_is_8) {
+      deserialized = std::stol(text);
+    } else if (sizeof_long_long_is_8) {
+      deserialized = std::stoll(text);
+    }
+  } catch (std::invalid_argument&) {
+    return NoInstanceAndDeserializationErrorWithCause<int64_t>(
+      common::Concat(
+        L"Expected to parse an xs:long from text, "
+        L"but got an invalid value: ",
+        common::Utf8ToWstring(text)
+      )
+    );
+  } catch (std::out_of_range&) {
+    return NoInstanceAndDeserializationErrorWithCause<int64_t>(
+      common::Concat(
+        L"Expected to parse an xs:long from text, "
+        L"but got a value out of the xs:long range: ",
+        common::Utf8ToWstring(text)
+      )
+    );
+  }
+
+  if (!deserialized.has_value()) {
+    throw std::logic_error(
+      "Neither int nor long nor long long are 8 bytes long, "
+      "but this should have been caught earlier in the static assert"
+    );
+  }
+
+  // NOTE (mristin):
+  // We consume the text node.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<int64_t>(reader);
+  }
+
+  return std::make_pair(
+    deserialized,
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<double>,
+  common::optional<DeserializationError>
+> DeserializeDouble(
+  xml_common::ReaderMergingText& reader
+) {
+  static_assert(
+    sizeof(double) == 8,
+    "DeserializeDouble expects double to be 8 bytes, "
+    "but the size of the double is not 8 bytes"
+  );
+
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeDouble. "
+      "DeserializeDouble expects no error node."
+    );
+  }
+  #endif
+
+  if (reader.node().kind() != xml_common::NodeKind::Text) {
+    return NoInstanceAndDeserializationErrorWithCause<double>(
+      common::Concat(
+        L"Expected to parse an xs:double from XML text, but got ",
+        xml_common::NodeToHumanReadableWstring(reader.node())
+      )
+    );
+  }
+
+  const std::string text(
+    xml_common::CollapseWhitespace(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::TextNode&
+      >(reader.node()).text
+    )
+  );
+
+  // NOTE (mristin):
+  // XSD names the three special values, and it is case-sensitive about it.
+  //
+  // See: https://www.w3.org/TR/xmlschema11-2/#double
+  double deserialized;
+
+  // NOTE (mristin):
+  // "+INF" is read although it is written as "INF": XSD 1.1 admits it, its
+  // production being (\+|-)?INF, and being liberal in what we accept costs
+  // nothing here.
+  if (text == "INF" || text == "+INF") {
+    deserialized = std::numeric_limits<double>::infinity();
+  } else if (text == "-INF") {
+    deserialized = -std::numeric_limits<double>::infinity();
+  } else if (text == "NaN") {
+    deserialized = std::numeric_limits<double>::quiet_NaN();
+  } else {
+    // NOTE (mristin):
+    // The lexical form has to be checked before the text is parsed.
+    // std::stod reads far more than XSD admits: a hexadecimal significand,
+    // so "0x10" comes out as 16; a trailing remainder, so "1.0abc" comes
+    // out as 1; and the spellings "inf", "infinity", "nan" and "NAN".
+    if (!xml_common::MatchesXsDoubleNumeral(text)) {
+      return NoInstanceAndDeserializationErrorWithCause<double>(
+        common::Concat(
+          L"Expected to parse an xs:double from text, "
+          L"but got an invalid value: ",
+          common::Utf8ToWstring(text)
+        )
+      );
+    }
+
+    // NOTE (mristin):
+    // std::stod refuses a literal whose value does not fit a double, by
+    // throwing std::out_of_range, and it does so at both ends. XSD asks for
+    // neither refusal: a literal too large rounds to an infinity, which is
+    // in the value space of xs:double, and one too small rounds to zero.
+    // std::strtod gives exactly that, reporting the range through errno,
+    // which we deliberately leave alone.
+    //
+    // The numeral has already been matched, so strtod consumes all of it.
+    deserialized = std::strtod(text.c_str(), nullptr);
+  }
+
+  // NOTE (mristin):
+  // We consume the text node.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<double>(reader);
+  }
+
+  return std::make_pair(
+    deserialized,
+    common::nullopt
+  );
+}
+
+std::pair<
+  common::optional<std::wstring>,
+  common::optional<DeserializationError>
+> DeserializeWstring(
+  xml_common::ReaderMergingText& reader
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeWstring. "
+      "DeserializeWstring expects no error node."
+    );
+  }
+  #endif
+
+  switch (reader.node().kind()) {
+    case xml_common::NodeKind::Stop:
+      // Encountering a stop node means that the string is empty.
+      return std::make_pair(std::wstring(), common::nullopt);
+    case xml_common::NodeKind::Text:
+      // We pass and continue decoding the text.
+      break;
+    default:
+      return NoInstanceAndDeserializationErrorWithCause<std::wstring>(
+        common::Concat(
+          L"Expected to parse an xs:string from XML text, but got ",
+            xml_common::NodeToHumanReadableWstring(reader.node())
+          )
+        );
+  }
+
+  const std::string& text(
+    static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+      const xml_common::TextNode&
+    >(reader.node()).text
+  );
+
+  std::wstring deserialized = common::Utf8ToWstring(text);
+
+  // NOTE (mristin):
+  // We consume the text node.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<std::wstring>(reader);
+  }
+
+  return std::make_pair(std::move(deserialized), common::nullopt);
+}
+
+std::pair<
+  common::optional<std::vector<std::uint8_t> >,
+  common::optional<DeserializationError>
+> DeserializeByteArray(
+  xml_common::ReaderMergingText& reader
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeByteArray. "
+      "DeserializeByteArray expects no error node."
+    );
+  }
+  #endif
+
+  switch (reader.node().kind()) {
+    case xml_common::NodeKind::Stop:
+      // Encountering a stop node means empty byte array.
+      return std::make_pair(
+        std::vector<std::uint8_t>(),
+        common::nullopt
+      );
+    case xml_common::NodeKind::Text:
+      // We pass and continue decoding the byte array.
+      break;
+    default:
+      return NoInstanceAndDeserializationErrorWithCause<
+        std::vector<std::uint8_t>
+      >(
+        common::Concat(
+          L"Expected to parse an xs:base64Binary from XML text, but got ",
+            xml_common::NodeToHumanReadableWstring(reader.node())
+          )
+        );
+  }
+
+  const std::string text(
+    xml_common::RemoveWhitespace(
+      static_cast<  // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+        const xml_common::TextNode&
+      >(reader.node()).text
+    )
+  );
+
+  if (!xml_common::MatchesXsBase64Binary(text)) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::vector<std::uint8_t>
+    >(
+      common::Concat(
+        L"Expected a text as base64-encoded bytes, but got: ",
+        common::Utf8ToWstring(text)
+      )
+    );
+  }
+
+  common::expected<
+    std::vector<std::uint8_t>,
+    std::string
+  > deserialized = stringification::Base64Decode(text);
+
+  if (!deserialized.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::vector<std::uint8_t>
+    >(
+      common::Concat(
+        L"Expected to parse an xs:base64Binary from text, "
+        L"but the value was invalid: ",
+        common::Utf8ToWstring(deserialized.error())
+      )
+    );
+  }
+
+  // NOTE (mristin):
+  // We consume the text node.
+  reader.Read();
+
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return NoInstanceAndDeserializationErrorFromReader<
+      std::vector<std::uint8_t>
+    >(reader);
+  }
+
+  return std::make_pair(
+    std::move(*deserialized),
+    common::nullopt
+  );
+}
+
+// endregion De-serialize primitives
+
+template <typename T, typename DeserializeT>
+std::pair<
+  common::optional<std::vector<T> >,
+  common::optional<DeserializationError>
+> DeserializeList(
+  xml_common::ReaderMergingText& reader,
+  const DeserializeT& deserialize_item
+) {
+  #ifdef DEBUG
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    throw std::logic_error(
+      "Unexpected unhandled XML error in DeserializeWstring. "
+      "DeserializeWstring expects no error node."
+    );
+  }
+  #endif
+
+  common::optional<DeserializationError> error;
+
+  error = SkipWhitespace(reader);
+  if (error.has_value()) {
+    return std::make_pair(
+      common::nullopt,
+      std::move(error)
+    );
+  }
+
+  // If we encounter the stop element then we reached the end of the list. If this is
+  // the first node we encounter then the list is empty, *i.e.*, contains no items.
+  if (reader.node().kind() == xml_common::NodeKind::Stop) {
+    return std::make_pair(
+      std::vector<T>(),
+      common::nullopt
+    );
+  } else {
+    // NOTE (mristin):
+    // We use std::deque here as it is a buffered list, while a std::list
+    // would incur a memory allocation on each push. We do not want to use
+    // std::vector as the number of elements in a list can be arbitrarily large
+    // leading potentially to out-of-memory errors since std::vector's double
+    // their size for amortized time complexity of O(1) for insertions.
+
+    std::deque<T> items;
+
+    size_t i = 0;
+
+    while (true) {
+      // NOTE (mristin):
+      // Anything but an item element is an error of the list, not of an item,
+      // so we do not prepend any index to its path.
+      if (reader.node().kind() != xml_common::NodeKind::Start) {
+        error = DeserializationError(
+          common::Concat(
+            L"Expected only item elements and whitespace text, but got ",
+            xml_common::NodeToHumanReadableWstring(reader.node())
+          )
+        );
+        break;
+      }
+
+      common::optional<T> item;
+
+      std::tie(
+        item,
+        error
+      ) = deserialize_item(reader);
+
+      if (error.has_value()) {
+        error->path.segments.emplace_front(
+          common::make_unique<xml_path::IndexSegment>(i)
+        );
+        break;
+      }
+
+      error = SkipWhitespace(reader);
+      if (error.has_value()) {
+        break;
+      }
+
+      items.emplace_back(*item);
+
+      if (reader.node().kind() == xml_common::NodeKind::Stop) {
+        break;
+      }
+
+      ++i;
+    }
+
+    if (!error.has_value()) {
+      auto result = std::vector<T>();
+      result.reserve(items.size());
+
+      for (auto& item : items) {
+        result.emplace_back(
+          std::move(item)
+        );
+    }
+
+      return std::make_pair(
+        std::move(result),
+        common::nullopt
+      );
+    } else {
+      return std::make_pair(
+        common::nullopt,
+        std::move(error)
+      );
+    }
+  }
+}
+
+/**
+ * \brief Assign the value read to \p target, or return the error of the read.
+ *
+ * We deliberately take the *result* of a read instead of the reader and
+ * the function which reads. The item readers of a tuple vary both in number
+ * and in type, so no signature taking the reader could serve every read;
+ * taking the result lets this single function serve all of them.
+ *
+ * \param target variable to be assigned the value read
+ * \param read result of the read
+ * \return the error, if the read failed
+ */
+template <typename T>
+common::optional<DeserializationError> ReadInto(
+  common::optional<T>& target,
+  std::pair<
+    common::optional<T>,
+    common::optional<DeserializationError>
+  >&& read
+) {
+  if (read.second.has_value()) {
+    return std::move(read.second);
+  }
+
+  target = std::move(read.first);
+
+  return common::nullopt;
+}
+
+namespace properties {
+
+enum class OfSomeItem : std::uint32_t {
+  kName = 0,
+  kNickname = 1
+};  // enum class OfSomeItem
+
+enum class OfSpecialItem : std::uint32_t {
+  kName = 0,
+  kNickname = 1,
+  kLevel = 2
+};  // enum class OfSpecialItem
+
+enum class OfContainer : std::uint32_t {
+  kItems = 0,
+  kSomeItems = 1,
+  kSpecialItems = 2
+};  // enum class OfContainer
+
+enum class OfWrapper : std::uint32_t {
+  kContainer = 0
+};  // enum class OfWrapper
+
+const std::size_t kPropertyCountOfSomeItem = 2;
+
+const std::unordered_map<
+  std::string,
+  OfSomeItem
+> kMapOfSomeItem = {
+  {
+    "name",
+    OfSomeItem::kName
+  },
+  {
+    "nickname",
+    OfSomeItem::kNickname
+  }
+};
+
+const std::size_t kPropertyCountOfSpecialItem = 3;
+
+const std::unordered_map<
+  std::string,
+  OfSpecialItem
+> kMapOfSpecialItem = {
+  {
+    "name",
+    OfSpecialItem::kName
+  },
+  {
+    "nickname",
+    OfSpecialItem::kNickname
+  },
+  {
+    "level",
+    OfSpecialItem::kLevel
+  }
+};
+
+const std::size_t kPropertyCountOfContainer = 3;
+
+const std::unordered_map<
+  std::string,
+  OfContainer
+> kMapOfContainer = {
+  {
+    "items",
+    OfContainer::kItems
+  },
+  {
+    "someItems",
+    OfContainer::kSomeItems
+  },
+  {
+    "specialItems",
+    OfContainer::kSpecialItems
+  }
+};
+
+const std::size_t kPropertyCountOfWrapper = 1;
+
+const std::unordered_map<
+  std::string,
+  OfWrapper
+> kMapOfWrapper = {
+  {
+    "container",
+    OfWrapper::kContainer
+  }
+};
+
+}  // namespace properties
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISomeItem>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> SomeItemFromSequence(
+  xml_common::ReaderMergingText& reader
+) {
+  // region Initialization
+
+  common::optional<std::wstring> the_name;
+
+  common::optional<std::wstring> the_nickname;
+
+  // endregion Initialization
+
+  common::optional<DeserializationError> error(
+    ReadProperties<
+      properties::kPropertyCountOfSomeItem
+    >(
+      reader,
+      properties::kMapOfSomeItem,
+      L"ISomeItem",
+      [&](
+        properties::OfSomeItem property
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfSomeItem::kName:
+            return ReadInto(
+              the_name,
+              DeserializeWstring(reader)
+            );
+          case properties::OfSomeItem::kNickname:
+            return ReadInto(
+              the_nickname,
+              DeserializeWstring(reader)
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfSomeItem",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  // region Check required properties
+
+  if (!the_name.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property name is missing"
+    );
+  }
+
+  // endregion Check required properties
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::SomeItem(
+        std::move(*the_name),
+        std::move(the_nickname)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::ISpecialItem>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> SpecialItemFromSequence(
+  xml_common::ReaderMergingText& reader
+) {
+  // region Initialization
+
+  common::optional<std::wstring> the_name;
+
+  common::optional<std::wstring> the_nickname;
+
+  common::optional<int64_t> the_level;
+
+  // endregion Initialization
+
+  common::optional<DeserializationError> error(
+    ReadProperties<
+      properties::kPropertyCountOfSpecialItem
+    >(
+      reader,
+      properties::kMapOfSpecialItem,
+      L"ISpecialItem",
+      [&](
+        properties::OfSpecialItem property
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfSpecialItem::kName:
+            return ReadInto(
+              the_name,
+              DeserializeWstring(reader)
+            );
+          case properties::OfSpecialItem::kNickname:
+            return ReadInto(
+              the_nickname,
+              DeserializeWstring(reader)
+            );
+          case properties::OfSpecialItem::kLevel:
+            return ReadInto(
+              the_level,
+              DeserializeInt64(reader)
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfSpecialItem",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  // region Check required properties
+
+  if (!the_name.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property name is missing"
+    );
+  }
+
+  if (!the_level.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property level is missing"
+    );
+  }
+
+  // endregion Check required properties
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::SpecialItem(
+        std::move(*the_name),
+        std::move(*the_level),
+        std::move(the_nickname)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::IContainer>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> ContainerFromSequence(
+  xml_common::ReaderMergingText& reader
+) {
+  // region Initialization
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::IItem>
+    >
+  > the_items;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::ISomeItem>
+    >
+  > the_some_items;
+
+  common::optional<
+    std::vector<
+      std::shared_ptr<types::ISpecialItem>
+    >
+  > the_special_items;
+
+  // endregion Initialization
+
+  common::optional<DeserializationError> error(
+    ReadProperties<
+      properties::kPropertyCountOfContainer
+    >(
+      reader,
+      properties::kMapOfContainer,
+      L"IContainer",
+      [&](
+        properties::OfContainer property
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfContainer::kItems:
+            return ReadInto(
+              the_items,
+              DeserializeList<
+                std::shared_ptr<types::IItem>
+              >(
+                reader,
+                ItemFromElement
+              )
+            );
+          case properties::OfContainer::kSomeItems:
+            return ReadInto(
+              the_some_items,
+              DeserializeList<
+                std::shared_ptr<types::ISomeItem>
+              >(
+                reader,
+                SomeItemFromElement
+              )
+            );
+          case properties::OfContainer::kSpecialItems:
+            return ReadInto(
+              the_special_items,
+              DeserializeList<
+                std::shared_ptr<types::ISpecialItem>
+              >(
+                reader,
+                SpecialItemFromElement
+              )
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfContainer",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  // region Check required properties
+
+  if (!the_items.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property items is missing"
+    );
+  }
+
+  if (!the_some_items.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property someItems is missing"
+    );
+  }
+
+  // endregion Check required properties
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::Container(
+        std::move(*the_items),
+        std::move(*the_some_items),
+        std::move(the_special_items)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+template <
+  typename T,
+  typename std::enable_if<
+    std::is_base_of<T, types::IWrapper>::value
+  >::type*
+>
+std::pair<
+  common::optional<std::shared_ptr<T> >,
+  common::optional<DeserializationError>
+> WrapperFromSequence(
+  xml_common::ReaderMergingText& reader
+) {
+  // region Initialization
+
+  common::optional<std::shared_ptr<types::IContainer> > the_container;
+
+  // endregion Initialization
+
+  common::optional<DeserializationError> error(
+    ReadProperties<
+      properties::kPropertyCountOfWrapper
+    >(
+      reader,
+      properties::kMapOfWrapper,
+      L"IWrapper",
+      [&](
+        properties::OfWrapper property
+      ) -> common::optional<DeserializationError> {
+        switch (property) {
+          case properties::OfWrapper::kContainer:
+            return ReadInto(
+              the_container,
+              ContainerFromSequence<
+                types::IContainer
+              >(reader)
+            );
+          default:
+            throw UnexpectedPropertyLiteralError(
+              "properties::OfWrapper",
+              property
+            );
+        }
+      }
+    )
+  );
+
+  if (error.has_value()) {
+    return NoInstanceAndDeserializationError<
+      std::shared_ptr<T>
+    >(
+      std::move(*error)
+    );
+  }
+
+  // region Check required properties
+
+  if (!the_container.has_value()) {
+    return NoInstanceAndDeserializationErrorWithCause<
+      std::shared_ptr<T>
+    >(
+      L"The required property container is missing"
+    );
+  }
+
+  // endregion Check required properties
+
+  return std::make_pair(
+    common::make_optional<
+      std::shared_ptr<T>
+    >(
+      // NOTE (mristin):
+      // We deliberately do not use std::make_shared here to avoid an unnecessary
+      // upcast.
+      new types::Wrapper(
+        std::move(*the_container)
+      )
+    ),
+    common::nullopt
+  );
+}
+
+template <typename ValueT, typename FromElementT>
+common::expected<
+  ValueT,
+  DeserializationError
+> DeserializeFrom(
+  std::istream& is,
+  const ReadingOptions& options,
+  const FromElementT& from_element
+) {
+  xml_common::ReaderMergingText reader(
+    is,
+    options.additional_attributes,
+    options.buffer_size
+  );
+
+  reader.Initialize();
+  if (reader.node().kind() == xml_common::NodeKind::Error) {
+    return common::make_unexpected(
+      DeserializationErrorFromReader(reader)
+    );
+  }
+
+  common::optional<DeserializationError> error = SkipBof(reader);
+  if (error.has_value()) {
+    return common::make_unexpected(
+      std::move(*error)
+    );
+  }
+
+  common::optional<ValueT> instance;
+
+  std::tie(
+    instance,
+    error
+  ) = DeserializeNestedElement<ValueT>(reader, from_element);
+
+  if (error.has_value()) {
+    return common::make_unexpected(
+      std::move(*error)
+    );
+  }
+
+  error = SkipWhitespace(reader);
+  if (error.has_value()) {
+    return common::make_unexpected(
+      std::move(*error)
+    );
+  }
+
+  error = CheckReaderAtEof(reader);
+  if (error.has_value()) {
+    return common::make_unexpected(
+      std::move(*error)
+    );
+  }
+
+  return std::move(*instance);
+}
+
+common::expected<
+  std::shared_ptr<types::IClass>,
+  DeserializationError
+> From(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IClass>
+  >(
+    is,
+    options,
+    ClassFromElement
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IItem>,
+  DeserializationError
+> ItemFrom(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IItem>
+  >(
+    is,
+    options,
+    ItemFromElement
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::ISomeItem>,
+  DeserializationError
+> SomeItemFrom(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::ISomeItem>
+  >(
+    is,
+    options,
+    SomeItemFromElement
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::ISpecialItem>,
+  DeserializationError
+> SpecialItemFrom(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::ISpecialItem>
+  >(
+    is,
+    options,
+    SpecialItemFromElement
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IContainer>,
+  DeserializationError
+> ContainerFrom(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IContainer>
+  >(
+    is,
+    options,
+    ContainerFromElement
+  );
+}
+
+common::expected<
+  std::shared_ptr<types::IWrapper>,
+  DeserializationError
+> WrapperFrom(
+  std::istream& is,
+  const ReadingOptions& options
+) {
+  return DeserializeFrom<
+    std::shared_ptr<types::IWrapper>
+  >(
+    is,
+    options,
+    WrapperFromElement
+  );
+}
+
+// endregion De-serialization
+
+// region Serialization
+
+// region SerializationException
+
+std::string RenderSerializationErrorMessage(
+  const std::wstring& cause,
+  const iteration::Path& path
+) {
+  return common::WstringToUtf8(
+    common::Concat(
+      L"Serialization failed at ",
+      path.ToWstring(),
+      L": ",
+      cause
+    )
+  );
+}
+
+SerializationException::SerializationException(
+  std::wstring cause
+) :
+  cause_(std::move(cause)),
+  path_(),
+  msg_(RenderSerializationErrorMessage(cause, path_)) {
+  // Intentionally empty.
+}
+
+SerializationException::SerializationException(
+  std::wstring cause,
+  iteration::Path path
+) :
+  cause_(std::move(cause)),
+  path_(std::move(path)),
+  msg_(RenderSerializationErrorMessage(cause, path)) {
+  // Intentionally empty.
+}
+
+const char* SerializationException::what() const noexcept {
+  return msg_.c_str();
+}
+
+const std::wstring& SerializationException::cause() const noexcept {
+  return cause_;
+}
+
+const iteration::Path& SerializationException::path() const noexcept {
+  return path_;
+}
+
+// endregion SerializationException
+
+common::optional<xml_common::SerializationError> WriteBool(
+  bool value,
+  xml_common::SelfClosingWriter& writer
+) {
+  writer.SerializeBool(value);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> WriteInt64(
+  int64_t value,
+  xml_common::SelfClosingWriter& writer
+) {
+  writer.SerializeInt64(value);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> WriteDouble(
+  double value,
+  xml_common::SelfClosingWriter& writer
+) {
+  writer.SerializeDouble(value);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> WriteWstring(
+  const std::wstring& value,
+  xml_common::SelfClosingWriter& writer
+) {
+  writer.SerializeWstring(value);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> WriteByteArray(
+  const std::vector<std::uint8_t>& value,
+  xml_common::SelfClosingWriter& writer
+) {
+  writer.SerializeByteArray(value);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Write \p value as an XML element named \p name.
+ *
+ * This is the only place where an element is framed. The element of a class,
+ * the `<v>` of a list item and the positional `<v1>`, `<v2>`, <i>etc.</i> of
+ * a tuple item differ only in the name and in the content, so all of them
+ * come through here.
+ *
+ * \param name of the XML element
+ * \param value to be written between the tags
+ * \param writer to write to
+ * \param write_content writes \p value between the tags
+ * \return an error, if any
+ */
+template <typename T, typename WriteT>
+common::optional<xml_common::SerializationError> WriteElement(
+  const char* name,
+  const T& value,
+  xml_common::SelfClosingWriter& writer,
+  const WriteT& write_content
+) {
+  writer.StartElement(name);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  common::optional<xml_common::SerializationError> error(
+    write_content(value, writer)
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  writer.StopElement(name);
+  if (writer.error().has_value()) {
+    return writer.move_error();
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * \brief Write \p value as the XML element of \p property.
+ *
+ * This is \ref WriteElement plus the one thing which a property knows and
+ * nothing beneath it does -- which property of the instance it is -- so that
+ * the path of the error is built as the stack unwinds.
+ *
+ * \param name of the XML element
+ * \param value of the property
+ * \param writer to write to
+ * \param property which the element stands for, for the path of the error
+ * \param write_content writes \p value between the tags
+ * \return an error, if any
+ */
+template <typename T, typename WriteT>
+common::optional<xml_common::SerializationError> WriteProperty(
+  const char* name,
+  const T& value,
+  xml_common::SelfClosingWriter& writer,
+  iteration::Property property,
+  const WriteT& write_content
+) {
+  common::optional<xml_common::SerializationError> error(
+    WriteElement(name, value, writer, write_content)
+  );
+
+  if (error.has_value()) {
+    error->path.segments.emplace_front(
+      common::make_unique<iteration::PropertySegment>(property)
+    );
+  }
+
+  return error;
+}
+
+/**
+ * \brief Write the instance behind \p value as the XML element of
+ * \p property.
+ *
+ * See the overload which takes the value itself for what is written and
+ * for the path of the error.
+ */
+template <typename T, typename WriteT>
+common::optional<xml_common::SerializationError> WriteProperty(
+  const char* name,
+  const std::shared_ptr<T>& value,
+  xml_common::SelfClosingWriter& writer,
+  iteration::Property property,
+  const WriteT& write_content
+) {
+  return WriteProperty(name, *value, writer, property, write_content);
+}
+
+/**
+ * \brief Write \p value as the XML element of \p property, or nothing at
+ * all if the property has not been given.
+ *
+ * See the overload which takes the value itself for what is written and
+ * for the path of the error.
+ */
+template <typename T, typename WriteT>
+common::optional<xml_common::SerializationError> WriteProperty(
+  const char* name,
+  const common::optional<T>& value,
+  xml_common::SelfClosingWriter& writer,
+  iteration::Property property,
+  const WriteT& write_content
+) {
+  if (!value.has_value()) {
+    return common::nullopt;
+  }
+
+  return WriteProperty(name, *value, writer, property, write_content);
+}
+
+/**
+ * \brief Write \p list as the XML element of \p property, every item as
+ * an XML element of its own.
+ *
+ * An instance is self-describing -- the name of its XML element is its model
+ * type -- so an item needs no positional tag here. A value encoded as text
+ * does need one, which is why a list of values is written by a function of
+ * its own instead of by this one with the name of the item passed in.
+ *
+ * \param name of the XML element
+ * \param list of the instances
+ * \param writer to write to
+ * \param property which the element stands for, for the path of the error
+ * \param write_item writes an item as an XML element of its own
+ * \return an error, if any
+ */
+template <typename T, typename WriteItemT>
+common::optional<xml_common::SerializationError> WriteListOfInstancesProperty(
+  const char* name,
+  const std::vector<T>& list,
+  xml_common::SelfClosingWriter& writer,
+  iteration::Property property,
+  const WriteItemT& write_item
+) {
+  return WriteProperty(
+    name,
+    list,
+    writer,
+    property,
+    [&write_item](
+      const std::vector<T>& a_list,
+      xml_common::SelfClosingWriter& a_writer
+    ) -> common::optional<xml_common::SerializationError> {
+      for (size_t i = 0; i < a_list.size(); ++i) {
+        common::optional<xml_common::SerializationError> error(
+          write_item(a_list[i], a_writer)
+        );
+
+        if (error.has_value()) {
+          error->path.segments.emplace_front(
+            common::make_unique<iteration::IndexSegment>(i)
+          );
+
+          return error;
+        }
+      }
+
+      return common::nullopt;
+    }
+  );
+}
+
+/**
+ * \brief Write \p list as the XML element of \p property, or nothing at all
+ * if the property has not been given.
+ *
+ * See the overload which takes the list itself for what is written and
+ * for the path of the error.
+ */
+template <typename T, typename WriteItemT>
+common::optional<xml_common::SerializationError> WriteListOfInstancesProperty(
+  const char* name,
+  const common::optional<std::vector<T> >& list,
+  xml_common::SelfClosingWriter& writer,
+  iteration::Property property,
+  const WriteItemT& write_item
+) {
+  if (!list.has_value()) {
+    return common::nullopt;
+  }
+
+  return WriteListOfInstancesProperty(
+    name,
+    *list,
+    writer,
+    property,
+    write_item
+  );
+}
+
+/**
+ * \brief Serialize \p that instance by dispatching to the appropriate concrete
+ * serialization function.
+ *
+ * \param that instance to be serialized
+ * \param writer to be write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeItemAsElement(
+  const types::IItem& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/** @copybrief SerializeItemAsElement(const types::IItem&, xml_common::SelfClosingWriter& */
+common::optional<xml_common::SerializationError> SerializeItemPtrAsElement(
+  const std::shared_ptr<types::IItem>& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSomeItemAsSequence(
+  const types::ISomeItem& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * \brief Serialize \p that instance by dispatching to the appropriate concrete
+ * serialization function.
+ *
+ * \param that instance to be serialized
+ * \param writer to be write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSomeItemAsElement(
+  const types::ISomeItem& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/** @copybrief SerializeSomeItemAsElement(const types::ISomeItem&, xml_common::SelfClosingWriter& */
+common::optional<xml_common::SerializationError> SerializeSomeItemPtrAsElement(
+  const std::shared_ptr<types::ISomeItem>& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSpecialItemAsSequence(
+  const types::ISpecialItem& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * Serialize \p that instance to an XML element
+ * `<specialItem>`.
+ *
+ * \param that instance to be serialized
+ * \return an error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSpecialItemAsElement(
+  const types::ISpecialItem& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/** @copybrief SerializeSpecialItemAsElement(const types::ISpecialItem&, xml_common::SelfClosingWriter& */
+common::optional<xml_common::SerializationError> SerializeSpecialItemPtrAsElement(
+  const std::shared_ptr<types::ISpecialItem>& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeContainerAsSequence(
+  const types::IContainer& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * Serialize \p that instance to an XML element
+ * `<container>`.
+ *
+ * \param that instance to be serialized
+ * \return an error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeContainerAsElement(
+  const types::IContainer& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/** @copybrief SerializeContainerAsElement(const types::IContainer&, xml_common::SelfClosingWriter& */
+common::optional<xml_common::SerializationError> SerializeContainerPtrAsElement(
+  const std::shared_ptr<types::IContainer>& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeWrapperAsSequence(
+  const types::IWrapper& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/**
+ * Serialize \p that instance to an XML element
+ * `<wrapper>`.
+ *
+ * \param that instance to be serialized
+ * \return an error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeWrapperAsElement(
+  const types::IWrapper& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+/** @copybrief SerializeWrapperAsElement(const types::IWrapper&, xml_common::SelfClosingWriter& */
+common::optional<xml_common::SerializationError> SerializeWrapperPtrAsElement(
+  const std::shared_ptr<types::IWrapper>& that,
+  xml_common::SelfClosingWriter& writer
+);
+
+common::optional<xml_common::SerializationError> SerializeItemAsElement(
+  const types::IItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  // NOTE (mristin):
+  // The dynamic casts are necessary due to virtual inheritance. Otherwise,
+  // we would have used static casts.
+
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return SerializeSomeItemAsElement(
+        dynamic_cast<
+          const types::ISomeItem&
+        >(that),
+        writer
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItemAsElement(
+        dynamic_cast<
+          const types::ISpecialItem&
+        >(that),
+        writer
+      );
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Invalid model type: ",
+          stringification::to_string(that.model_type())
+        )
+      );
+  };
+}
+
+common::optional<xml_common::SerializationError> SerializeItemPtrAsElement(
+  const std::shared_ptr<types::IItem>& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return SerializeItemAsElement(*that, writer);
+}
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSomeItemAsSequence(
+  const types::ISomeItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  common::optional<xml_common::SerializationError> error;
+
+  error = WriteProperty(
+    "name",
+    that.name(),
+    writer,
+    iteration::Property::kName,
+    WriteWstring
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  error = WriteProperty(
+    "nickname",
+    that.nickname(),
+    writer,
+    iteration::Property::kNickname,
+    WriteWstring
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  return common::nullopt;
+}
+
+/**
+ * Serialize \p that instance to an XML element
+ * `<someItem>`.
+ *
+ * No dispatch is performed in this function. It is expected that you call
+ * \ref SerializeSomeItemAsElement, which will then dispatch into this function.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return an error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeConcreteSomeItemAsElement(
+  const types::ISomeItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return WriteElement(
+    "someItem",
+    that,
+    writer,
+    SerializeSomeItemAsSequence
+  );
+}
+
+common::optional<xml_common::SerializationError> SerializeSomeItemAsElement(
+  const types::ISomeItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  // NOTE (mristin):
+  // The dynamic casts are necessary due to virtual inheritance. Otherwise,
+  // we would have used static casts.
+
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return SerializeConcreteSomeItemAsElement(
+        that,
+        writer
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItemAsElement(
+        dynamic_cast<
+          const types::ISpecialItem&
+        >(that),
+        writer
+      );
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Invalid model type: ",
+          stringification::to_string(that.model_type())
+        )
+      );
+  };
+}
+
+common::optional<xml_common::SerializationError> SerializeSomeItemPtrAsElement(
+  const std::shared_ptr<types::ISomeItem>& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return SerializeSomeItemAsElement(*that, writer);
+}
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeSpecialItemAsSequence(
+  const types::ISpecialItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  common::optional<xml_common::SerializationError> error;
+
+  error = WriteProperty(
+    "name",
+    that.name(),
+    writer,
+    iteration::Property::kName,
+    WriteWstring
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  error = WriteProperty(
+    "nickname",
+    that.nickname(),
+    writer,
+    iteration::Property::kNickname,
+    WriteWstring
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  error = WriteProperty(
+    "level",
+    that.level(),
+    writer,
+    iteration::Property::kLevel,
+    WriteInt64
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> SerializeSpecialItemAsElement(
+  const types::ISpecialItem& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return WriteElement(
+    "specialItem",
+    that,
+    writer,
+    SerializeSpecialItemAsSequence
+  );
+}
+
+common::optional<xml_common::SerializationError> SerializeSpecialItemPtrAsElement(
+  const std::shared_ptr<types::ISpecialItem>& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return SerializeSpecialItemAsElement(*that, writer);
+}
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeContainerAsSequence(
+  const types::IContainer& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  common::optional<xml_common::SerializationError> error;
+
+  error = WriteListOfInstancesProperty(
+    "items",
+    that.items(),
+    writer,
+    iteration::Property::kItems,
+    SerializeItemPtrAsElement
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  error = WriteListOfInstancesProperty(
+    "someItems",
+    that.some_items(),
+    writer,
+    iteration::Property::kSomeItems,
+    SerializeSomeItemPtrAsElement
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  error = WriteListOfInstancesProperty(
+    "specialItems",
+    that.special_items(),
+    writer,
+    iteration::Property::kSpecialItems,
+    SerializeSpecialItemPtrAsElement
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> SerializeContainerAsElement(
+  const types::IContainer& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return WriteElement(
+    "container",
+    that,
+    writer,
+    SerializeContainerAsSequence
+  );
+}
+
+common::optional<xml_common::SerializationError> SerializeContainerPtrAsElement(
+  const std::shared_ptr<types::IContainer>& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return SerializeContainerAsElement(*that, writer);
+}
+
+/**
+ * \brief Serialize \p that instance as a sequence of XML elements.
+ *
+ * Each XML element corresponds to a property.
+ *
+ * \param that instance to be serialized
+ * \param writer to write to
+ * \return error, if any
+ */
+common::optional<xml_common::SerializationError> SerializeWrapperAsSequence(
+  const types::IWrapper& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  common::optional<xml_common::SerializationError> error;
+
+  error = WriteProperty(
+    "container",
+    that.container(),
+    writer,
+    iteration::Property::kContainer,
+    SerializeContainerAsSequence
+  );
+  if (error.has_value()) {
+    return error;
+  }
+
+  return common::nullopt;
+}
+
+common::optional<xml_common::SerializationError> SerializeWrapperAsElement(
+  const types::IWrapper& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return WriteElement(
+    "wrapper",
+    that,
+    writer,
+    SerializeWrapperAsSequence
+  );
+}
+
+common::optional<xml_common::SerializationError> SerializeWrapperPtrAsElement(
+  const std::shared_ptr<types::IWrapper>& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  return SerializeWrapperAsElement(*that, writer);
+}
+
+common::optional<xml_common::SerializationError> WriteClass(
+  const types::IClass& that,
+  xml_common::SelfClosingWriter& writer
+) {
+  // NOTE (mristin):
+  // The dynamic casts are necessary due to virtual inheritance. Otherwise,
+  // we would have used static casts.
+
+  switch (that.model_type()) {
+    case types::ModelType::kSomeItem:
+      return SerializeSomeItemAsElement(
+        dynamic_cast<
+          const types::ISomeItem&
+        >(that),
+        writer
+      );
+    case types::ModelType::kSpecialItem:
+      return SerializeSpecialItemAsElement(
+        dynamic_cast<
+          const types::ISpecialItem&
+        >(that),
+        writer
+      );
+    case types::ModelType::kContainer:
+      return SerializeContainerAsElement(
+        dynamic_cast<
+          const types::IContainer&
+        >(that),
+        writer
+      );
+    case types::ModelType::kWrapper:
+      return SerializeWrapperAsElement(
+        dynamic_cast<
+          const types::IWrapper&
+        >(that),
+        writer
+      );
+    default:
+      throw std::invalid_argument(
+        common::Concat(
+          "Invalid model type: ",
+          stringification::to_string(that.model_type())
+        )
+      );
+  };
+}
+
+void Serialize(
+  const types::IClass& that,
+  const WritingOptions& options,
+  std::ostream& os
+) {
+  if (options.write_declaration) {
+    os << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
+    if (os.bad()) {
+      throw SerializationException(
+        xml_common::kTheOutputStreamIsInABadState
+      );
+    }
+  }
+
+  // NOTE (mristin):
+  // The namespace is declared on the root element and on no other one, so we
+  // hand it to the writer instead of asking at every single element whether it
+  // is the root. The writer takes the attributes at the very first element and
+  // leaves nothing behind.
+  xml_common::SelfClosingWriter writer(
+    os,
+    options.write_namespace
+      ? " xmlns=\"https://dummy.com\""
+      : ""
+  );
+
+  common::optional<xml_common::SerializationError> error(
+    WriteClass(that, writer)
+  );
+
+  if (error.has_value()) {
+    throw SerializationException(
+      std::move(error->cause),
+      std::move(error->path)
+    );
+  }
+}
+
+// endregion Serialization
+
+}  // namespace xmlization
+}  // namespace dummy
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/catch_main.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/catch_main.cpp
new file mode 100644
index 000000000..bcec31566
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/catch_main.cpp
@@ -0,0 +1,12 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Define the main function of Catch2 for all the tests.
+ *
+ * Compiling the implementation of Catch2 takes long, so we compile it only once
+ * in this translation unit, and link all the tests against it.
+ */
+
+#define CATCH_CONFIG_MAIN
+#include <catch2/catch.hpp>
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.cpp
new file mode 100644
index 000000000..fd536c267
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.cpp
@@ -0,0 +1,422 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+
+#include <dummy/stringification.hpp>
+#include <dummy/wstringification.hpp>
+
+#include <catch2/catch.hpp>
+
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <queue>
+#include <set>
+#include <stdexcept>
+#include <type_traits>
+
+namespace our = dummy;
+
+namespace fs = std::filesystem;
+
+namespace test {
+namespace common {
+
+static std::optional<std::string> GetEnv(const char *variable_name) {
+  // NOTE (empwilli): MSVC complains about getenv being unsafe.
+  // This should not be an issue as we don't run our tests in parallel, though,
+  // so we use getenv_s in Windows. However, this function is a Microsoft
+  // extension.
+#ifdef _WIN32
+  char buffer[256];
+  size_t len;
+  errno_t error = getenv_s(
+    &len, buffer, sizeof(buffer), variable_name
+  );
+  if (error != 0) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "The getenv_s returned an error code ",
+        std::to_string(error),
+        " when asking for the variable ",
+        variable_name
+      )
+    );
+  }
+
+  if (len == 0) {
+    return std::nullopt;
+  }
+
+  if (buffer[len - 1] != 0) {
+    throw std::logic_error(
+      our::common::Concat(
+        "Expected the last byte of buffer for getenv_s on ",
+        variable_name,
+        " to be zero, but got ",
+        std::to_string(static_cast<std::uint8_t>(buffer[len - 1]))
+      )
+    );
+  }
+
+  return std::optional { std::string(buffer, len - 1) };
+#else
+  auto value = getenv(variable_name);
+
+  if (value == nullptr) {
+    return std::nullopt;
+  }
+
+  return std::optional { std::string(value) };
+#endif
+}
+
+bool DetermineRecordMode() {
+  const char* variable_name = "DUMMY_TEST_RECORD_MODE";
+
+  auto result = GetEnv(variable_name);
+
+  if (!result.has_value())
+  {
+    return false;
+  }
+
+  static const std::set<std::string> hot_value_set{
+    "on", "ON", "On",
+    "true", "TRUE", "True",
+    "1",
+    "yes", "Yes", "YES"
+  };
+  return hot_value_set.find(result.value()) != hot_value_set.end();
+}
+
+std::filesystem::path DetermineTestDataDir() {
+  const char* variable_name = "DUMMY_TEST_DATA_DIR";
+
+  auto result = GetEnv(variable_name);
+
+  if (!result.has_value())
+  {
+    throw std::runtime_error(
+      our::common::Concat(
+        "The environment variable ",
+        variable_name,
+        " has not been set."
+      )
+    );
+  }
+
+  return fs::path(result.value());
+}
+
+/**
+ * Write `text` to the given `path` encoded as UTF-8.
+ */
+void MustWriteWstringAsUtf8(
+  const std::filesystem::path& path,
+  const std::wstring& text
+) {
+  std::ofstream ofs(path, std::ios::binary);
+
+  const std::string encoded = our::common::WstringToUtf8(text);
+  ofs.write(encoded.data(), encoded.size());
+
+  if (ofs.fail()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to write to ",
+        path.string(),
+        "; the fail bit of the file stream is set"
+      )
+    );
+  }
+
+  if (ofs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to write to ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+}
+
+/**
+ * Read the content of the file `path` and decode it from UTF-8.
+ */
+std::wstring MustReadWstringAsUtf8(
+  const std::filesystem::path& path
+) {
+  std::ifstream ifs(path, std::ios::binary);
+  ifs.seekg(0, std::ios::end);
+  std::streamoff size = ifs.tellg();
+  if (size < 0) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Unexpected negative size of ",
+        path.string(),
+        ": ",
+        std::to_string(size)
+      )
+    );
+  }
+
+  std::string buffer(static_cast<size_t>(size), ' ');
+  ifs.seekg(0);
+  ifs.read(&buffer[0], size);
+
+  if (ifs.fail()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read from ",
+        path.string(),
+        "; the fail bit of the file stream is set"
+      )
+    );
+  }
+
+  if (ifs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read from ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+
+  try {
+    return our::common::Utf8ToWstring(buffer);
+  } catch (const std::exception& exception) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to de-code ",
+        path.string(),
+        " as UTF-8: ",
+        exception.what()
+      )
+    );
+  }
+}
+
+/**
+ * Write `text` to the given `path` as binary.
+ */
+void MustWriteString(
+  const std::filesystem::path& path,
+  const std::string& text
+) {
+  std::ofstream ofs(path, std::ios::binary);
+
+  ofs.write(text.data(), text.size());
+
+  if (ofs.fail()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to write to ",
+        path.string(),
+        "; the fail bit of the file stream is set"
+      )
+    );
+  }
+
+  if (ofs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to write to ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+}
+
+/**
+ * Read the content of the file `path` as binary.
+ */
+std::string MustReadString(
+  const std::filesystem::path& path
+) {
+  std::ifstream ifs(path, std::ios::binary);
+  ifs.seekg(0, std::ios::end);
+  std::streamoff size = ifs.tellg();
+  if (size < 0) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Unexpected negative size of ",
+        path.string(),
+        ": ",
+        std::to_string(size)
+      )
+    );
+  }
+
+  std::string buffer(static_cast<size_t>(size), ' ');
+  ifs.seekg(0);
+  ifs.read(&buffer[0], size);
+
+  if (ifs.fail()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read from ",
+        path.string(),
+        "; the fail bit of the file stream is set"
+      )
+    );
+  }
+
+  if (ifs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read from ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+
+  return buffer;
+}
+
+std::wstring TraceMark(
+  const dummy::types::IClass& that
+) {
+  const std::wstring model_type = our::wstringification::to_wstring(
+    that.model_type()
+  );
+  return model_type;
+}
+
+bool StringEndsWith(
+  const std::string& text,
+  const std::string& suffix
+) {
+  if (text.size() < suffix.size()) {
+    return false;
+  }
+
+  return (
+    text.substr(text.size() - suffix.size(), suffix.size())
+      == suffix
+  );
+}
+
+std::deque<std::filesystem::path> FindFilesBySuffixRecursively(
+  const std::filesystem::path& root,
+  const std::string& suffix
+) {
+  if (!fs::exists(root)) {
+    return std::deque<std::filesystem::path>();
+  }
+
+  if (!fs::is_directory(root)) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Expected to search for files with suffix recursively in ",
+        root.string(),
+        ", but it is not a directory"
+      )
+    );
+  }
+
+  std::deque<fs::path> result;
+
+  for (
+    const fs::directory_entry& entry
+    : fs::recursive_directory_iterator(root)
+    ) {
+    if (
+      StringEndsWith(
+        entry.path().filename().string(),
+        suffix
+      )
+      ) {
+      result.push_back(entry.path());
+    }
+  }
+
+  std::sort(result.begin(), result.end());
+
+  return result;
+}
+
+std::deque<std::filesystem::path> ListSubdirectories(
+  const std::filesystem::path& root
+) {
+  if (!fs::exists(root)) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "The root directory which you wanted to list for subdirectories "
+        "does not exist: ",
+        root.string()
+      )
+    );
+  }
+
+  if (!fs::is_directory(root)) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "The path that you specified as a root directory which you wanted to "
+        "list for subdirectories is not a directory: ",
+        root.string()
+      )
+    );
+  }
+
+  std::deque<fs::path> result;
+
+  for (
+    const fs::directory_entry& entry
+    : fs::directory_iterator(root)
+    ) {
+    if (fs::is_directory(entry.path())) {
+      result.push_back(entry.path());
+    }
+  }
+
+  std::sort(result.begin(), result.end());
+  return result;
+}
+
+void AssertContentEqualsExpectedOrRecord(
+  const std::string& content,
+  const std::filesystem::path& path
+) {
+  const bool record_mode = DetermineRecordMode();
+  if (record_mode) {
+    fs::create_directories(path.parent_path());
+
+    MustWriteString(path, content);
+  } else {
+    INFO(
+      our::common::Concat(
+        "Expected to compare the content against "
+        "the recorded file: ",
+        path.string(),
+        ", but the file does not exist. If you want to re-record, "
+        "please set the environment variable DUMMY_TEST_RECORD_MODE "
+        "to 'ON'"
+      )
+    )
+    REQUIRE(std::filesystem::exists(path));
+
+    const std::string expected = MustReadString(path);
+    INFO(
+      our::common::Concat(
+        "Got unexpected content, which should have been equal "
+        "to the content of the file: ",
+        path.string()
+      )
+    )
+    REQUIRE(content == expected);
+  }
+}
+
+}  // namespace common
+}  // namespace test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.hpp
new file mode 100644
index 000000000..fa5b4f8e5
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common.hpp
@@ -0,0 +1,142 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#ifndef TEST_COMMON_GUARD_
+#define TEST_COMMON_GUARD_
+
+#include <dummy/types.hpp>
+
+#include <nlohmann/json.hpp>
+
+#include <deque>
+#include <filesystem>
+
+/**
+* Provide common functionalities shared across the tests.
+*/
+namespace test {
+namespace common {
+
+/**
+ * Set to true if we run tests in the record mode according to the environment
+ * variable `DUMMY_TEST_RECORD_MODE`.
+ *
+ * \remark It is tedious to record manually all the expected error messages. Therefore
+ * we include this variable to steer the automatic recording. We intentionally
+ * intertwine the recording code with the test code to keep them close to each other
+ * so that they are easier to maintain.
+ */
+bool DetermineRecordMode();
+
+/**
+ * Point to the directory with the test data according to the environment
+ * variable `DUMMY_TEST_DATA_DIR`.
+ */
+std::filesystem::path DetermineTestDataDir();
+
+/**
+ * Represent `that` instance as a human-readable line of an iteration trace.
+ */
+std::wstring TraceMark(
+  const dummy::types::IClass& that
+);
+
+/**
+ * Find files beneath the `root` recursively which have the `suffix`.
+ *
+ * If the `root` does not exist, return an empty deque.
+ *
+ * If the `root` is not a directory, throw a runtime error.
+ *
+ * The files are sorted.
+ */
+std::deque<std::filesystem::path> FindFilesBySuffixRecursively(
+  const std::filesystem::path& root,
+  const std::string& suffix
+);
+
+/**
+ * List non-recursively the subdirectories contained in the \p root.
+ *
+ * @param root directory that you want to list
+ * @return subdirectories beneath \p root, sorted
+ */
+std::deque<std::filesystem::path> ListSubdirectories(
+  const std::filesystem::path& root
+);
+
+/**
+ * Check that the content coincides with the file or re-record if in record mode.
+ */
+void AssertContentEqualsExpectedOrRecord(
+  const std::string& content,
+  const std::filesystem::path& path
+);
+
+template<typename T>
+std::string JoinStrings(const T& container, const std::string& delimiter) {
+  static_assert(std::is_same<typename T::value_type, std::string>::value);
+
+  size_t size = 0;
+  for (const std::string& part : container
+    ) {
+    size += part.size();
+  }
+  size += delimiter.size() * (container.size() - 1);
+
+  std::string result;
+  result.reserve(size);
+
+  auto it = container.begin();
+  for (size_t i = 0; i < container.size() - 1; ++i) {
+    result.append(*it);
+    result.append(delimiter);
+    ++it;
+  }
+
+  result.append(*it);
+
+  return result;
+}
+
+template<typename T>
+std::wstring JoinWstrings(const T& container, const std::wstring& delimiter) {
+  if (container.size() == 0) {
+    return L"";
+  }
+
+  static_assert(std::is_same<typename T::value_type, std::wstring>::value);
+
+  size_t size = 0;
+  for (const std::wstring& part : container
+    ) {
+    size += part.size();
+  }
+  size += delimiter.size() * (container.size() - 1);
+
+  std::wstring result;
+  result.reserve(size);
+
+  auto it = container.begin();
+  for (size_t i = 0; i < container.size() - 1; ++i) {
+    result.append(*it);
+    result.append(delimiter);
+    ++it;
+  }
+
+  result.append(*it);
+
+  return result;
+}
+
+std::string MustReadString(
+  const std::filesystem::path& path
+);
+
+}  // namespace common
+}  // namespace test
+
+#endif  // TEST_COMMON_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.cpp
new file mode 100644
index 000000000..7cd16d582
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.cpp
@@ -0,0 +1,335 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_examples.hpp"
+#include "./common_xmlization.hpp"
+
+#include <dummy/iteration.hpp>
+#include <dummy/stringification.hpp>
+
+#include <filesystem>
+
+namespace our = dummy;
+
+namespace test {
+namespace common {
+namespace examples {
+
+template<typename T>
+struct StaticTypeName;
+
+template<>
+struct StaticTypeName<
+  our::types::ISomeItem
+> {
+  static const char* name;
+};
+const char* StaticTypeName<
+  our::types::ISomeItem
+>::name = "ISomeItem";
+
+template<>
+struct StaticTypeName<
+  our::types::ISpecialItem
+> {
+  static const char* name;
+};
+const char* StaticTypeName<
+  our::types::ISpecialItem
+>::name = "ISpecialItem";
+
+template<>
+struct StaticTypeName<
+  our::types::IContainer
+> {
+  static const char* name;
+};
+const char* StaticTypeName<
+  our::types::IContainer
+>::name = "IContainer";
+
+template<>
+struct StaticTypeName<
+  our::types::IWrapper
+> {
+  static const char* name;
+};
+const char* StaticTypeName<
+  our::types::IWrapper
+>::name = "IWrapper";
+
+std::shared_ptr<
+  our::types::ISomeItem
+> LoadSomeItem(
+  const std::filesystem::path& path
+) {
+  
+
+  std::shared_ptr<
+    our::types::IClass
+  > abstract = test::common::xmlization::MustReadInstance(
+    path
+  );
+
+  std::shared_ptr<
+    our::types::ISomeItem
+  > instance(
+    std::dynamic_pointer_cast<
+      our::types::ISomeItem
+    >(
+      abstract
+    )
+  );
+
+  if (instance == nullptr) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to cast the instance to ISomeItem from ",
+        path.string()
+      )
+    );
+  }
+
+  return instance;
+}
+
+std::shared_ptr<
+  our::types::ISomeItem
+> LoadMinSomeItem() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "someItem"
+      / "minimal.xml"
+  );
+
+  return LoadSomeItem(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::ISomeItem
+> LoadMaxSomeItem() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "someItem"
+      / "maximal.xml"
+  );
+
+  return LoadSomeItem(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::ISpecialItem
+> LoadSpecialItem(
+  const std::filesystem::path& path
+) {
+  
+
+  std::shared_ptr<
+    our::types::IClass
+  > abstract = test::common::xmlization::MustReadInstance(
+    path
+  );
+
+  std::shared_ptr<
+    our::types::ISpecialItem
+  > instance(
+    std::dynamic_pointer_cast<
+      our::types::ISpecialItem
+    >(
+      abstract
+    )
+  );
+
+  if (instance == nullptr) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to cast the instance to ISpecialItem from ",
+        path.string()
+      )
+    );
+  }
+
+  return instance;
+}
+
+std::shared_ptr<
+  our::types::ISpecialItem
+> LoadMinSpecialItem() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "specialItem"
+      / "minimal.xml"
+  );
+
+  return LoadSpecialItem(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::ISpecialItem
+> LoadMaxSpecialItem() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "specialItem"
+      / "maximal.xml"
+  );
+
+  return LoadSpecialItem(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::IContainer
+> LoadContainer(
+  const std::filesystem::path& path
+) {
+  
+
+  std::shared_ptr<
+    our::types::IClass
+  > abstract = test::common::xmlization::MustReadInstance(
+    path
+  );
+
+  std::shared_ptr<
+    our::types::IContainer
+  > instance(
+    std::dynamic_pointer_cast<
+      our::types::IContainer
+    >(
+      abstract
+    )
+  );
+
+  if (instance == nullptr) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to cast the instance to IContainer from ",
+        path.string()
+      )
+    );
+  }
+
+  return instance;
+}
+
+std::shared_ptr<
+  our::types::IContainer
+> LoadMinContainer() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "container"
+      / "minimal.xml"
+  );
+
+  return LoadContainer(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::IContainer
+> LoadMaxContainer() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "container"
+      / "maximal.xml"
+  );
+
+  return LoadContainer(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::IWrapper
+> LoadWrapper(
+  const std::filesystem::path& path
+) {
+  
+
+  std::shared_ptr<
+    our::types::IClass
+  > abstract = test::common::xmlization::MustReadInstance(
+    path
+  );
+
+  std::shared_ptr<
+    our::types::IWrapper
+  > instance(
+    std::dynamic_pointer_cast<
+      our::types::IWrapper
+    >(
+      abstract
+    )
+  );
+
+  if (instance == nullptr) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to cast the instance to IWrapper from ",
+        path.string()
+      )
+    );
+  }
+
+  return instance;
+}
+
+std::shared_ptr<
+  our::types::IWrapper
+> LoadMinWrapper() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "wrapper"
+      / "minimal.xml"
+  );
+
+  return LoadWrapper(
+    path
+  );
+}
+
+std::shared_ptr<
+  our::types::IWrapper
+> LoadMaxWrapper() {
+  const std::filesystem::path path(
+    test::common::DetermineTestDataDir()
+      / "Xml"
+      / "Expected"
+      / "wrapper"
+      / "maximal.xml"
+  );
+
+  return LoadWrapper(
+    path
+  );
+}
+
+}  // namespace examples
+}  // namespace common
+}  // namespace test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.hpp
new file mode 100644
index 000000000..4b6a6a395
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_examples.hpp
@@ -0,0 +1,88 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+* Load minimal and maximal examples from an XML file.
+*/
+
+#ifndef TEST_COMMON_EXAMPLES_GUARD_
+#define TEST_COMMON_EXAMPLES_GUARD_
+
+#include <dummy/types.hpp>
+
+namespace test {
+namespace common {
+namespace examples {
+
+/**
+ * Load a minimal example of ISomeItem by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::ISomeItem
+> LoadMinSomeItem();
+
+/**
+ * Load a maximal example of ISomeItem by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::ISomeItem
+> LoadMaxSomeItem();
+
+/**
+ * Load a minimal example of ISpecialItem by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::ISpecialItem
+> LoadMinSpecialItem();
+
+/**
+ * Load a maximal example of ISpecialItem by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::ISpecialItem
+> LoadMaxSpecialItem();
+
+/**
+ * Load a minimal example of IContainer by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::IContainer
+> LoadMinContainer();
+
+/**
+ * Load a maximal example of IContainer by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::IContainer
+> LoadMaxContainer();
+
+/**
+ * Load a minimal example of IWrapper by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::IWrapper
+> LoadMinWrapper();
+
+/**
+ * Load a maximal example of IWrapper by
+ * de-serializing it from an XML file.
+ */
+std::shared_ptr<
+  dummy::types::IWrapper
+> LoadMaxWrapper();
+
+}  // namespace examples
+}  // namespace common
+}  // namespace test
+
+#endif // TEST_COMMON_EXAMPLES_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.cpp
new file mode 100644
index 000000000..5f673d146
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.cpp
@@ -0,0 +1,93 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common_jsonization.hpp"
+
+#include <dummy/common.hpp>
+
+#include <fstream>
+
+namespace our = dummy;
+
+namespace test {
+namespace common {
+namespace jsonization {
+
+nlohmann::json MustReadJson(const std::filesystem::path& path) {
+  std::ifstream ifs(path);
+
+  nlohmann::json result;
+  try {
+    result = nlohmann::json::parse(ifs);
+  } catch (nlohmann::json::parse_error& exception) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read JSON from ",
+        path.string(),
+        ": ",
+        exception.what()
+      )
+    );
+  }
+
+  if (ifs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read JSON from ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+
+  if (ifs.fail()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read JSON from ",
+        path.string(),
+        "; the fail bit of the file stream is set"
+      )
+    );
+  }
+
+  if (!ifs.eof()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read JSON from ",
+        path.string(),
+        "; the EOF bit is not set meaning that we did not parse all the content"
+      )
+    );
+  }
+
+  return result;
+}
+
+std::optional<std::string> CompareJsons(
+  const nlohmann::json& that,
+  const nlohmann::json& other
+) {
+  const nlohmann::json patch = nlohmann::json::diff(that, other);
+
+  if (!patch.is_array()) {
+    throw std::logic_error(
+      our::common::Concat(
+        "Expected the patch to be an array, but got ",
+        patch.type_name()
+      )
+    );
+  }
+
+  if (patch.size() != 0) {
+    return nlohmann::to_string(patch);
+  }
+
+  return std::nullopt;
+}
+
+}  // namespace jsonization
+}  // namespace common
+}  // namespace test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.hpp
new file mode 100644
index 000000000..029a98621
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_jsonization.hpp
@@ -0,0 +1,42 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Provide methods which are used throughout the jsonization tests.
+ */
+#ifndef TEST_COMMON_JSONIZATION_GUARD_
+#define TEST_COMMON_JSONIZATION_GUARD_
+
+#include <nlohmann/json.hpp>
+
+#include <optional>
+#include <vector>
+#include <string>
+
+namespace test {
+namespace common {
+namespace jsonization {
+
+/**
+ * Read the content of the `path` and parse it as JSON.
+ */
+nlohmann::json MustReadJson(const std::filesystem::path& path);
+
+/**
+ * Compare two JSON values.
+ *
+ * Return the JSON patch, if there is any difference.
+ */
+std::optional<std::string> CompareJsons(
+  const nlohmann::json& that,
+  const nlohmann::json& other
+);
+
+}  // namespace jsonization
+}  // namespace common
+}  // namespace test
+
+#endif  // TEST_COMMON_JSONIZATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.cpp
new file mode 100644
index 000000000..42aceb674
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.cpp
@@ -0,0 +1,637 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common_xmlization.hpp"
+#include "./common.hpp"
+
+#include <dummy/xmlization.hpp>
+
+#pragma warning(push, 0)
+#include <expat.h>
+#pragma warning(pop)
+
+#include <fstream>
+
+namespace our = dummy;
+
+namespace test {
+namespace common {
+namespace xmlization {
+
+std::shared_ptr<
+  dummy::types::IClass
+> MustReadInstance(
+  const std::filesystem::path& path
+) {
+  std::ifstream ifs(path);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > instance = our::xmlization::From(
+    ifs
+  );
+
+  if (ifs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to read XML from ",
+        path.string(),
+        "; the bad bit of the file stream is set"
+      )
+    );
+  }
+
+  if (!instance.has_value()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to parse the instance from the XML file ",
+        path.string(),
+        ": ",
+        our::common::WstringToUtf8(instance.error().path.ToWstring()),
+        ": ",
+        our::common::WstringToUtf8(instance.error().cause)
+      )
+    );
+  }
+
+  return *instance;
+}
+
+namespace canonicalizer {
+
+struct INode {
+  std::string text;
+
+  INode(
+    std::string a_text
+  ) :
+    text(a_text) {
+    // Intentionally empty.
+  }
+
+  virtual std::unique_ptr<INode> Copy() const = 0;
+  virtual ~INode() = default;
+};
+
+struct StartNode : INode {
+  std::string name;
+
+  StartNode(
+    std::string a_name,
+    std::string a_text
+  ) :
+    INode(std::move(a_text)),
+    name(std::move(a_name)) {
+    // Intentionally empty.
+  }
+
+  std::unique_ptr<INode> Copy() const override {
+    return std::make_unique<StartNode>(*this);
+  }
+
+  ~StartNode() override = default;
+};
+
+struct TextNode : INode {
+  TextNode(
+    std::string a_text
+  ) : INode(std::move(a_text)) {
+    // Intentionally empty.
+  }
+
+  std::unique_ptr<INode> Copy() const override {
+    return std::make_unique<TextNode>(*this);
+  }
+
+  ~TextNode() override = default;
+};
+
+struct StopNode : INode {
+  std::string name;
+
+  StopNode(
+    std::string a_name,
+    std::string a_text
+  ) :
+    INode(std::move(a_text)),
+    name(std::move(a_name)) {
+    // Intentionally empty.
+  }
+
+  std::unique_ptr<INode> Copy() const override {
+    return std::make_unique<StopNode>(*this);
+  }
+
+  ~StopNode() override = default;
+};
+
+/**
+ * Structure the data passed over to Expat XML reader.
+ */
+struct OurData {
+  XML_Parser parser;
+  std::optional<std::string> error;
+
+  std::deque<std::unique_ptr<INode> > nodes;
+
+  OurData(
+    XML_Parser a_parser
+  ) :
+    parser(a_parser) {
+    // Intentionally empty.
+  }
+};  // struct OurData
+
+our::common::expected<
+  std::string,
+  std::string
+> EscapeForXmlAttribute(const std::string_view& text) {
+  // NOTE (mristin):
+  // See: https://stackoverflow.com/questions/19766669/which-characters-are-permitted-in-xml-attributes
+  //
+  // In addition, we assume that we will always surround an attribute by a double-quote.
+
+  size_t size = 0;
+  for (char character : text
+    ) {
+    switch (character) {
+      case '<':size += sizeof("&lt;");
+        break;
+      case '"':size += sizeof("&quot;");
+        break;
+      case '\0':
+        return our::common::unexpected<std::string>(
+          "Unexpected zero character in the text to be escaped "
+          "for XML attribute. The XML format does not allow zero characters, "
+          "not even in escaped form."
+        );
+      default:++size;
+    }
+  }
+
+  std::string result;
+  result.reserve(size);
+
+  for (char character : text
+    ) {
+    switch (character) {
+      case '<':result.append("&lt;");
+        break;
+      case '"':result.append("&quot;");
+        break;
+      default:result.push_back(character);
+    }
+  }
+
+  return result;
+}
+
+our::common::expected<
+  std::string,
+  std::string
+> EscapeForXmlText(const std::string_view& text) {
+  size_t size = 0;
+  for (char character : text
+    ) {
+    switch (character) {
+      case '<':size += sizeof("&lt;");
+        break;
+      case '>':size += sizeof("&gt;");
+        break;
+      case '&':size += sizeof("&amp;");
+        break;
+      case '\'':size += sizeof("&apos;");
+        break;
+      case '"':size += sizeof("&quot;");
+        break;
+      case '\0':
+        return our::common::unexpected(
+          "Unexpected zero character in the text to be escaped "
+          "for XML attribute. The XML format does not allow zero characters, "
+          "not even in escaped form."
+        );
+      default:++size;
+    }
+  }
+
+  if (text.size() == size) {
+    return std::string(text);
+  }
+
+  std::string result;
+  result.reserve(size);
+
+  for (char character : text
+    ) {
+    switch (character) {
+      case '<':result.append("&lt;");
+        break;
+      case '>':result.append("&gt;");
+        break;
+      case '&':result.append("&amp;");
+        break;
+      case '\'':result.append("&apos;");
+        break;
+      case '"':result.append("&quot;");
+        break;
+      default:result.push_back(character);
+    }
+  }
+
+  return result;
+}
+
+void XMLCALL OnStartElement(
+  void* user_data,
+  const char* name,
+  const char* attributes[]
+) {
+  auto our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->error.has_value()) {
+    return;
+  }
+
+  std::stringstream ss;
+  ss << "<" << name;
+
+  for (size_t i = 0; attributes[i] != nullptr; i += 2
+    ) {
+    const char* attribute_name = attributes[i];
+    const char* attribute_value = attributes[i + 1];
+
+    our::common::expected<
+      std::string,
+      std::string
+    > escaped = EscapeForXmlAttribute(
+      std::string_view(
+        attribute_value,
+        strlen(attribute_value)
+      )
+    );
+    if (!escaped.has_value()) {
+      our_data->error = escaped.error();
+      XML_StopParser(our_data->parser, false);
+      return;
+    }
+
+    ss
+      << " "
+      << attribute_name << "=\""
+      << *escaped
+      << "\"";
+  }
+
+  ss << ">";
+
+  our_data->nodes.emplace_back(
+    our::common::make_unique<StartNode>(
+      name,
+      ss.str()
+    )
+  );
+}
+
+void XMLCALL OnStopElement(
+  void* user_data,
+  const char* name
+) {
+  auto* our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->error.has_value()) {
+    return;
+  }
+
+  our_data->nodes.emplace_back(
+    our::common::make_unique<StopNode>(
+      name,
+      our::common::Concat(
+        "</", name, ">"
+      )
+    )
+  );
+}
+
+void XMLCALL OnText(
+  void* user_data,
+  const char* val,
+  int len
+) {
+  auto our_data = static_cast<OurData*>(user_data);
+
+  // NOTE (mristin):
+  // Since Expat continues parsing and adding nodes even if the parsing is
+  // suspended (see the documentation of `XML_StopParser`), we have to ignore
+  // any further events.
+  if (our_data->error.has_value()) {
+    return;
+  }
+
+  our::common::expected<
+    std::string,
+    std::string
+  > escaped = EscapeForXmlText(std::string_view(val, len));
+
+  if (!escaped.has_value()) {
+    our_data->error = std::move(escaped.error());
+    XML_StopParser(our_data->parser, false);
+    return;
+  }
+
+  our_data->nodes.emplace_back(
+    our::common::make_unique<TextNode>(
+      std::move(*escaped)
+    )
+  );
+}
+
+std::deque<std::unique_ptr<INode> > MergeTextNodes(
+  const std::deque<std::unique_ptr<INode> >& nodes
+) {
+  std::deque<std::string> parts;
+
+  std::deque<std::unique_ptr<INode> > result;
+
+  for (const std::unique_ptr<INode>& node : nodes
+    ) {
+    auto start_node = dynamic_cast<const StartNode*>(node.get());
+    auto stop_node = dynamic_cast<const StopNode*>(node.get());
+
+    if (start_node != nullptr || stop_node != nullptr) {
+      if (!parts.empty()) {
+        result.emplace_back(
+          std::make_unique<TextNode>(
+            test::common::JoinStrings(parts, "")
+          )
+        );
+        parts.clear();
+      }
+
+      result.emplace_back(node->Copy());
+
+      continue;
+    }
+
+    auto text_node = dynamic_cast<const TextNode*>(node.get());
+    if (text_node != nullptr) {
+      parts.push_back(text_node->text);
+    }
+  }
+
+  if (!parts.empty()) {
+    result.emplace_back(
+      std::make_unique<TextNode>(
+        test::common::JoinStrings(parts, "")
+      )
+    );
+  }
+
+  return result;
+}
+
+bool IsWhitespace(const std::string& text) {
+  for (const char character : text
+    ) {
+    switch (character) {
+      case '\n':continue;
+      case '\t':continue;
+      case '\r':continue;
+      case ' ':continue;
+      default:return false;
+    }
+  }
+  return true;
+}
+
+/**
+ * Remove the whitespace between two start/stop nodes with differing names.
+ */
+std::deque<std::unique_ptr<INode> > RemoveNonSemanticWhiteSpace(
+  const std::deque<std::unique_ptr<INode> >& nodes
+) {
+  std::deque<std::unique_ptr<INode> > result;
+
+  if (nodes.size() <= 2) {
+    for (const auto& node : nodes
+      ) {
+      result.emplace_back(node->Copy());
+    }
+    return result;
+  }
+
+  INode* previous = nullptr;
+  StartNode* previous_as_start = nullptr;
+
+  auto it = nodes.begin();
+  INode* current = it->get();
+  StartNode* current_as_start = dynamic_cast<StartNode*>(current);
+  TextNode* current_as_text = dynamic_cast<TextNode*>(current);
+
+  ++it;
+  INode* lookahead = it->get();
+  StartNode* lookahead_as_start = dynamic_cast<StartNode*>(lookahead);
+  StopNode* lookahead_as_stop = dynamic_cast<StopNode*>(lookahead);
+  TextNode* lookahead_as_text = dynamic_cast<TextNode*>(lookahead);
+
+  ++it;
+
+  while (true) {
+    // region Determine what to do
+
+    // If not set, we include the current node in the result.
+    bool ignore = (
+      current_as_text != nullptr
+        && IsWhitespace(current_as_text->text)
+        && (
+          previous == nullptr
+            || lookahead == nullptr
+            || !(
+              previous_as_start != nullptr
+                && lookahead_as_stop != nullptr
+                && previous_as_start->name == lookahead_as_stop->name
+            )
+        )
+    );
+    // endregion
+
+    // region Act
+    if (!ignore) {
+      result.emplace_back(current->Copy());
+    }
+    // endregion
+
+    // region Shift
+    previous = current;
+    previous_as_start = current_as_start;
+
+    current = lookahead;
+    current_as_start = lookahead_as_start;
+    current_as_text = lookahead_as_text;
+
+    if (current == nullptr) {
+      break;
+    }
+
+    if (it == nodes.end()) {
+      lookahead = nullptr;
+      lookahead_as_start = nullptr;
+      lookahead_as_stop = nullptr;
+      lookahead_as_text = nullptr;
+    } else {
+      lookahead = it->get();
+      lookahead_as_start = dynamic_cast<StartNode*>(lookahead);
+      lookahead_as_stop = dynamic_cast<StopNode*>(lookahead);
+      lookahead_as_text = dynamic_cast<TextNode*>(lookahead);
+
+      ++it;
+    }
+    // endregion
+  }
+
+  return result;
+}
+
+}  // namespace canonicalizer
+
+std::string CanonicalizeXml(
+  const std::string& xml
+) {
+  const char namespace_separator = ':';
+  XML_Parser parser = XML_ParserCreateNS(nullptr, namespace_separator);
+
+  std::unique_ptr<canonicalizer::OurData> our_data(
+    our::common::make_unique<canonicalizer::OurData>(
+      parser
+    )
+  );
+
+  XML_SetUserData(parser, our_data.get());
+  XML_SetElementHandler(
+    parser,
+    canonicalizer::OnStartElement,
+    canonicalizer::OnStopElement
+  );
+  XML_SetCharacterDataHandler(parser, canonicalizer::OnText);
+
+  XML_Status status = XML_Parse(
+    parser,
+    xml.data(),
+    static_cast<int>(xml.size()),
+    true
+  );
+
+  if (status == XML_STATUS_ERROR) {
+    XML_Error error_code = XML_GetErrorCode(parser);
+
+    std::string message;
+
+    if (error_code == XML_ERROR_ABORTED) {
+      if (!our_data->error.has_value()) {
+        throw std::logic_error(
+          "The XML parsing was aborted, "
+          "but the error in our_data was empty"
+        );
+      }
+
+      message = std::move(*our_data->error);
+    } else {
+      const XML_LChar* error_str = XML_ErrorString(error_code);
+      message = error_str;
+    }
+
+    throw std::invalid_argument(
+      our::common::Concat(
+        "Failed to parse XML for canonicalization: ",
+        std::to_string(XML_GetCurrentLineNumber(parser)),
+        ":",
+        std::to_string(XML_GetCurrentColumnNumber(parser)),
+        ": ",
+        message
+      )
+    );
+  }
+
+  std::deque<
+    std::unique_ptr<canonicalizer::INode>
+  > nodes(
+    std::move(our_data->nodes)
+  );
+
+  nodes = canonicalizer::MergeTextNodes(nodes);
+
+  nodes = canonicalizer::RemoveNonSemanticWhiteSpace(nodes);
+
+  size_t size = 0;
+  for (const auto& node : nodes) {
+    size += node->text.size();
+  }
+
+  std::string result;
+  result.reserve(size);
+
+  for (const auto& node : nodes) {
+    result.append(node->text);
+  }
+
+  return result;
+}
+
+std::shared_ptr<
+  dummy::types::IClass
+> MustDeserializeFile(
+  const std::filesystem::path& path
+) {
+  std::ifstream ifs(path, std::ios::binary);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(
+    ifs
+  );
+
+  if (ifs.bad()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "The file stream is in the bad mode after "
+        "reading and parsing the file as XML: ",
+        path.string()
+      )
+    );
+  }
+
+  if (!deserialized.has_value()) {
+    throw std::runtime_error(
+      our::common::Concat(
+        "Failed to de-serialize from ",
+        path.string(),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().path.ToWstring()
+        ),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().cause
+        )
+      )
+    );
+  }
+
+  return std::move(deserialized.value());
+}
+
+}  // namespace xmlization
+}  // namespace common
+}  // namespace test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.hpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.hpp
new file mode 100644
index 000000000..d2fd9bbb2
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/common_xmlization.hpp
@@ -0,0 +1,50 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Provide methods which are used throughout the jsonization tests.
+ */
+#ifndef TEST_COMMON_XMLIZATION_GUARD_
+#define TEST_COMMON_XMLIZATION_GUARD_
+
+#include <dummy/types.hpp>
+
+#include <filesystem>
+#include <string>
+#include <vector>
+
+namespace test {
+namespace common {
+namespace xmlization {
+
+/**
+ * Read the content of the `path` and parse it as XML representation of an instance.
+ */
+std::shared_ptr<
+  dummy::types::IClass
+> MustReadInstance(
+  const std::filesystem::path& path
+);
+
+/**
+ * Canonicalize the `xml` by stripping away any XML text between the stop and start
+ * nodes.
+ */
+std::string CanonicalizeXml(
+  const std::string& xml
+);
+
+std::shared_ptr<
+  dummy::types::IClass
+> MustDeserializeFile(
+  const std::filesystem::path& path
+);
+
+}  // namespace xmlization
+}  // namespace common
+}  // namespace test
+
+#endif  // TEST_COMMON_XMLIZATION_GUARD_
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_descent_and_descent_once.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_descent_and_descent_once.cpp
new file mode 100644
index 000000000..516e29cd1
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_descent_and_descent_once.cpp
@@ -0,0 +1,264 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_examples.hpp"
+#include "./common_xmlization.hpp"
+
+#include <dummy/iteration.hpp>
+#include <dummy/stringification.hpp>
+#include <dummy/types.hpp>
+
+#include <catch2/catch.hpp>
+
+#include <deque>
+
+namespace our = dummy;
+
+const std::filesystem::path& DetermineXmlDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "Xml";
+  }
+
+  return *result;
+}
+
+const std::filesystem::path& DetermineDescentDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "Descent";
+  }
+
+  return *result;
+}
+
+const std::filesystem::path& DetermineDescentOnceDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "DescentOnce";
+  }
+
+  return *result;
+}
+
+void AssertOrRerecordDescent(
+  const std::filesystem::path& xml_path,
+  const std::filesystem::path& trace_path
+) {
+  std::shared_ptr<
+    our::types::IClass
+  > instance(
+    test::common::xmlization::MustDeserializeFile(xml_path)
+  );
+
+  std::deque<std::wstring> parts;
+
+  for (
+    const std::shared_ptr<our::types::IClass>& something
+    : our::iteration::Descent(instance)
+  ) {
+    parts.emplace_back(test::common::TraceMark(*something));
+    parts.push_back(L"\n");
+  }
+
+  test::common::AssertContentEqualsExpectedOrRecord(
+    our::common::WstringToUtf8(
+      test::common::JoinWstrings(parts, L"")
+    ),
+    trace_path
+  );
+}
+
+void AssertOrRerecordDescentOnce(
+  const std::shared_ptr<our::types::IClass>& instance,
+  const std::filesystem::path& trace_path
+) {
+  std::deque<std::wstring> parts;
+
+  for (
+    const std::shared_ptr<our::types::IClass>& something
+    : our::iteration::DescentOnce(instance)
+  ) {
+    parts.emplace_back(test::common::TraceMark(*something));
+    parts.push_back(L"\n");
+  }
+
+  test::common::AssertContentEqualsExpectedOrRecord(
+    our::common::WstringToUtf8(
+      test::common::JoinWstrings(parts, L"")
+    ),
+    trace_path
+  );
+}
+
+TEST_CASE("Test Descent over an SomeItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "someItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    const std::filesystem::path parent(
+      (
+        DetermineDescentDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+      ).parent_path()
+    );
+
+    const std::filesystem::path trace_path(
+      parent
+        / (path.filename().string() + ".trace")
+    );
+
+    AssertOrRerecordDescent(path, trace_path);
+  }
+}
+
+TEST_CASE("Test DescentOnce over an SomeItem") {
+  const std::shared_ptr<
+    our::types::ISomeItem
+  > instance(
+    test::common::examples::LoadMaxSomeItem()
+  );
+
+  const std::filesystem::path trace_path(
+    DetermineDescentOnceDir()
+      / "MaxSomeItem.trace"
+  );
+
+  AssertOrRerecordDescentOnce(instance, trace_path);
+}
+
+TEST_CASE("Test Descent over an SpecialItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "specialItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    const std::filesystem::path parent(
+      (
+        DetermineDescentDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+      ).parent_path()
+    );
+
+    const std::filesystem::path trace_path(
+      parent
+        / (path.filename().string() + ".trace")
+    );
+
+    AssertOrRerecordDescent(path, trace_path);
+  }
+}
+
+TEST_CASE("Test DescentOnce over an SpecialItem") {
+  const std::shared_ptr<
+    our::types::ISpecialItem
+  > instance(
+    test::common::examples::LoadMaxSpecialItem()
+  );
+
+  const std::filesystem::path trace_path(
+    DetermineDescentOnceDir()
+      / "MaxSpecialItem.trace"
+  );
+
+  AssertOrRerecordDescentOnce(instance, trace_path);
+}
+
+TEST_CASE("Test Descent over an Container") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "container",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    const std::filesystem::path parent(
+      (
+        DetermineDescentDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+      ).parent_path()
+    );
+
+    const std::filesystem::path trace_path(
+      parent
+        / (path.filename().string() + ".trace")
+    );
+
+    AssertOrRerecordDescent(path, trace_path);
+  }
+}
+
+TEST_CASE("Test DescentOnce over an Container") {
+  const std::shared_ptr<
+    our::types::IContainer
+  > instance(
+    test::common::examples::LoadMaxContainer()
+  );
+
+  const std::filesystem::path trace_path(
+    DetermineDescentOnceDir()
+      / "MaxContainer.trace"
+  );
+
+  AssertOrRerecordDescentOnce(instance, trace_path);
+}
+
+TEST_CASE("Test Descent over an Wrapper") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "wrapper",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    const std::filesystem::path parent(
+      (
+        DetermineDescentDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+      ).parent_path()
+    );
+
+    const std::filesystem::path trace_path(
+      parent
+        / (path.filename().string() + ".trace")
+    );
+
+    AssertOrRerecordDescent(path, trace_path);
+  }
+}
+
+TEST_CASE("Test DescentOnce over an Wrapper") {
+  const std::shared_ptr<
+    our::types::IWrapper
+  > instance(
+    test::common::examples::LoadMaxWrapper()
+  );
+
+  const std::filesystem::path trace_path(
+    DetermineDescentOnceDir()
+      / "MaxWrapper.trace"
+  );
+
+  AssertOrRerecordDescentOnce(instance, trace_path);
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_dispatch.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_dispatch.cpp
new file mode 100644
index 000000000..0701b94e2
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_dispatch.cpp
@@ -0,0 +1,125 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_jsonization.hpp"
+#include "./common_examples.hpp"
+
+#include <dummy/jsonization.hpp>
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("Test the round-trip of an expected IItem") {
+  const std::shared_ptr<
+    our::types::ISomeItem
+  > concrete_instance(
+    test::common::examples::LoadMinSomeItem()
+  );
+
+  const nlohmann::json json = our::jsonization::Serialize(
+    *concrete_instance
+  );
+
+  our::common::expected<
+    std::shared_ptr<
+      our::types::IItem
+    >,
+    our::jsonization::DeserializationError
+  > instance = our::jsonization::ItemFrom(
+    json
+  );
+
+  if (!instance.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to deserialize a IItem "
+        "from a minimal ISomeItem: ",
+        our::common::WstringToUtf8(instance.error().path.ToWstring()),
+        ": ",
+        our::common::WstringToUtf8(instance.error().cause)
+      )
+    )
+    CHECK(instance.has_value());
+  }
+
+  const nlohmann::json another_json = our::jsonization::Serialize(
+    **instance
+  );
+
+  const std::optional<
+    std::string
+  > patch_message = test::common::jsonization::CompareJsons(
+    json,
+    another_json
+  );
+  if (patch_message.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to make a round-trip of a IItem "
+        "over a minimal ISomeItem: ",
+        *patch_message
+        )
+      )
+      CHECK(!patch_message.has_value());
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected ISomeItem") {
+  const std::shared_ptr<
+    our::types::ISpecialItem
+  > concrete_instance(
+    test::common::examples::LoadMinSpecialItem()
+  );
+
+  const nlohmann::json json = our::jsonization::Serialize(
+    *concrete_instance
+  );
+
+  our::common::expected<
+    std::shared_ptr<
+      our::types::ISomeItem
+    >,
+    our::jsonization::DeserializationError
+  > instance = our::jsonization::SomeItemFrom(
+    json
+  );
+
+  if (!instance.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to deserialize a ISomeItem "
+        "from a minimal ISpecialItem: ",
+        our::common::WstringToUtf8(instance.error().path.ToWstring()),
+        ": ",
+        our::common::WstringToUtf8(instance.error().cause)
+      )
+    )
+    CHECK(instance.has_value());
+  }
+
+  const nlohmann::json another_json = our::jsonization::Serialize(
+    **instance
+  );
+
+  const std::optional<
+    std::string
+  > patch_message = test::common::jsonization::CompareJsons(
+    json,
+    another_json
+  );
+  if (patch_message.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to make a round-trip of a ISomeItem "
+        "over a minimal ISpecialItem: ",
+        *patch_message
+        )
+      )
+      CHECK(!patch_message.has_value());
+  }
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_of_concrete_classes.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_of_concrete_classes.cpp
new file mode 100644
index 000000000..987c8d300
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_jsonization_of_concrete_classes.cpp
@@ -0,0 +1,467 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_jsonization.hpp"
+
+#include <dummy/jsonization.hpp>
+
+#include <limits>
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+template<class ClassT>
+void AssertRoundTrip(
+  const std::filesystem::path& path,
+  std::function<
+    our::common::expected<
+      std::shared_ptr<ClassT>,
+      our::jsonization::DeserializationError
+    >(const nlohmann::json&, bool)
+  > deserialization_function
+) {
+  const nlohmann::json json = test::common::jsonization::MustReadJson(path);
+
+  our::common::expected<
+    std::shared_ptr<ClassT>,
+    our::jsonization::DeserializationError
+  > deserialized = deserialization_function(json, false);
+
+  if (!deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to de-serialize from ",
+        path.string(),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().path.ToWstring()
+        ),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().cause
+        )
+      )
+    )
+    REQUIRE(deserialized.has_value());
+  }
+
+  nlohmann::json another_json = our::jsonization::Serialize(
+    *(deserialized.value())
+  );
+
+  std::optional<std::string> diff_message = test::common::jsonization::CompareJsons(
+    json,
+    another_json
+  );
+  if (diff_message.has_value()) {
+    INFO(
+      our::common::Concat(
+        "The JSON round-trip from ",
+        path.string(),
+        " failed. There is a diff between the original JSON "
+        "and the serialized one: ",
+        *diff_message
+      )
+    )
+    REQUIRE(!diff_message.has_value());
+  }
+}
+
+template<typename ClassT>
+void AssertDeserializationFailure(
+  const std::filesystem::path& path,
+  std::function<
+    our::common::expected<
+      std::shared_ptr<ClassT>,
+      our::jsonization::DeserializationError
+    >(const nlohmann::json&, bool)
+  > deserialization_function,
+  const std::filesystem::path& error_path
+) {
+  const nlohmann::json json = test::common::jsonization::MustReadJson(path);
+
+  our::common::expected<
+    std::shared_ptr<ClassT>,
+    our::jsonization::DeserializationError
+  > deserialized = deserialization_function(json, false);
+
+  if (deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Expected the de-serialization to fail on ",
+        path.string(),
+        ", but the de-serialization succeeded"
+      )
+    )
+    REQUIRE(!deserialized.has_value());
+  }
+
+  test::common::AssertContentEqualsExpectedOrRecord(
+    our::common::Concat(
+      our::common::WstringToUtf8(
+        deserialized.error().path.ToWstring()
+      ),
+      ": ",
+      our::common::WstringToUtf8(
+        deserialized.error().cause
+      )
+    ),
+    error_path
+  );
+}
+
+const std::filesystem::path& DetermineJsonDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "Json";
+  }
+
+  return *result;
+}
+
+const std::filesystem::path& DetermineErrorDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "JsonizationError";
+  }
+
+  return *result;
+}
+
+template<class ClassT>
+std::shared_ptr<ClassT> MustDeserializeTheFirstExpected(
+  const std::string& model_type,
+  std::function<
+    our::common::expected<
+      std::shared_ptr<ClassT>,
+      our::jsonization::DeserializationError
+    >(const nlohmann::json&, bool)
+  > deserialization_function
+) {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineJsonDir() / "Expected" / model_type,
+      ".json"
+    )
+  );
+
+  INFO("We expect at least one recorded example of " + model_type)
+  REQUIRE(!paths.empty());
+
+  const nlohmann::json json = test::common::jsonization::MustReadJson(
+    paths.front()
+  );
+
+  our::common::expected<
+    std::shared_ptr<ClassT>,
+    our::jsonization::DeserializationError
+  > deserialized = deserialization_function(json, false);
+
+  INFO(
+    our::common::Concat(
+      "Failed to de-serialize from ",
+      paths.front().string()
+    )
+  )
+  REQUIRE(deserialized.has_value());
+
+  return deserialized.value();
+}
+
+/**
+ * Assert that \p that instance can not be serialized to JSON, and that
+ * the failure is reported at \p expected_path.
+ */
+void AssertSerializationFailsAt(
+  const our::types::IClass& that,
+  const std::string& expected_path
+) {
+  try {
+    our::jsonization::Serialize(that);
+  } catch (const our::jsonization::SerializationException& exception) {
+    const std::string observed_path(
+      our::common::WstringToUtf8(
+        exception.path().ToWstring()
+      )
+    );
+
+    INFO(
+      our::common::Concat(
+        "Expected the serialization to fail at ",
+        expected_path,
+        ", but it failed at ",
+        observed_path,
+        ": ",
+        our::common::WstringToUtf8(exception.cause())
+      )
+    )
+    REQUIRE(observed_path == expected_path);
+
+    return;
+  }
+
+  INFO(
+    our::common::Concat(
+      "Expected the serialization to fail at ",
+      expected_path,
+      ", but it succeeded"
+    )
+  )
+  REQUIRE(false);
+}
+
+TEST_CASE("Test the round-trip of an expected SomeItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineJsonDir()
+        / "Expected"
+        / "SomeItem",
+      ".json"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertRoundTrip<
+      our::types::ISomeItem
+    >(path, our::jsonization::SomeItemFrom);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected SomeItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineJsonDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "SomeItem",
+        ".json"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineJsonDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure<
+        our::types::ISomeItem
+      >(
+        path,
+        our::jsonization::SomeItemFrom,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected SpecialItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineJsonDir()
+        / "Expected"
+        / "SpecialItem",
+      ".json"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertRoundTrip<
+      our::types::ISpecialItem
+    >(path, our::jsonization::SpecialItemFrom);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected SpecialItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineJsonDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "SpecialItem",
+        ".json"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineJsonDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure<
+        our::types::ISpecialItem
+      >(
+        path,
+        our::jsonization::SpecialItemFrom,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected Container") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineJsonDir()
+        / "Expected"
+        / "Container",
+      ".json"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertRoundTrip<
+      our::types::IContainer
+    >(path, our::jsonization::ContainerFrom);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected Container") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineJsonDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "Container",
+        ".json"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineJsonDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure<
+        our::types::IContainer
+      >(
+        path,
+        our::jsonization::ContainerFrom,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected Wrapper") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineJsonDir()
+        / "Expected"
+        / "Wrapper",
+      ".json"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertRoundTrip<
+      our::types::IWrapper
+    >(path, our::jsonization::WrapperFrom);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected Wrapper") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineJsonDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "Wrapper",
+        ".json"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineJsonDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure<
+        our::types::IWrapper
+      >(
+        path,
+        our::jsonization::WrapperFrom,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE(
+  "Test the serialization failure on an integer outside the range representable in JSON "
+  "at .level of SpecialItem"
+) {
+  for (
+    const int64_t value
+    : {
+      9007199254740992LL,
+      -9007199254740992LL
+    }
+  ) {
+    std::shared_ptr<our::types::ISpecialItem> instance(
+      MustDeserializeTheFirstExpected<our::types::ISpecialItem>(
+        "SpecialItem",
+        our::jsonization::SpecialItemFrom
+      )
+    );
+
+    instance->set_level(value);
+
+    AssertSerializationFailsAt(
+      *instance,
+      ".level"
+    );
+  }
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_revm.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_revm.cpp
new file mode 100644
index 000000000..737925e52
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_revm.cpp
@@ -0,0 +1,286 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Test the virtual machine for matching regular expressions.
+ */
+
+#include "dummy/common.hpp"
+#include "dummy/revm.hpp"
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("Test character in an empty range") {
+  std::vector<our::revm::Range> ranges;
+
+  REQUIRE(
+    !our::revm::CharacterInRanges(ranges, L'M')
+  );
+}
+
+TEST_CASE("Test character in a single range") {
+  std::vector<our::revm::Range> ranges = {
+    our::revm::Range(L'A', L'Z')
+  };
+
+  REQUIRE(CharacterInRanges(ranges, L'M'));
+  REQUIRE(!CharacterInRanges(ranges, L'a'));
+}
+
+TEST_CASE("Test character in multiple ranges") {
+  std::vector<our::revm::Range> ranges = {
+    our::revm::Range(L'A', L'C'),
+    our::revm::Range(L'D', L'F'),
+    our::revm::Range(L'G', L'I'),
+    our::revm::Range(L'J', L'L'),
+    our::revm::Range(L'M', L'N')
+  };
+
+  for (wchar_t character = L'A'; character < L'Z'; ++character) {
+    const std::string message(
+      our::common::WstringToUtf8(
+        L"Testing for character: " + std::wstring(1, character)
+      )
+    );
+
+    if (character <= L'N') {
+      INFO(message)
+      REQUIRE(
+        CharacterInRanges(ranges, character)
+      );
+    } else {
+      INFO(message)
+      REQUIRE(
+        !CharacterInRanges(ranges, character)
+      );
+    }
+  }
+}
+
+TEST_CASE("Test pattern ^a$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^a+b+$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSplit>(0, 2)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'b')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSplit>(2, 4)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(!our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(our::revm::Match(program, L"ab"));
+  REQUIRE(our::revm::Match(program, L"aabb"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^a|b$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSplit>(1, 3)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionJump>(4)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'b')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^a?$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSplit>(1, 2)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^a*$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSplit>(1, 3)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionJump>(0)
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^[a-b]$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionSet>(
+      std::vector<our::revm::Range>{
+        our::revm::Range(L'a', L'b')
+      }
+    )
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern ^[^a-b]$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionNotSet>(
+      std::vector<our::revm::Range>{
+        our::revm::Range(L'a', L'b')
+      }
+    )
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionEnd>()
+  );
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+  );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(!our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+  REQUIRE(our::revm::Match(program, L"c"));
+  REQUIRE(!our::revm::Match(program, L"cc"));
+}
+
+TEST_CASE("Test pattern ^.$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(std::make_unique<our::revm::InstructionAny>());
+  program.emplace_back(std::make_unique<our::revm::InstructionEnd>());
+  program.emplace_back(std::make_unique<our::revm::InstructionMatch>());
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(!our::revm::Match(program, L"aa"));
+  REQUIRE(our::revm::Match(program, L"b"));
+  REQUIRE(!our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+TEST_CASE("Test pattern with arbitrary suffix ^a.*$") {
+  std::vector<std::unique_ptr<our::revm::Instruction> > program;
+
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionChar>(L'a')
+      );
+
+  // NOTE (mristin):
+  // Usually, the last two instructions would be `end` followed by a `match`.
+  // However, we can optimize by having a single `match` without an `end` so that
+  // we return early.
+  program.emplace_back(
+    std::make_unique<our::revm::InstructionMatch>()
+      );
+
+  REQUIRE(!our::revm::Match(program, L""));
+  REQUIRE(our::revm::Match(program, L"a"));
+  REQUIRE(our::revm::Match(program, L"aa"));
+  REQUIRE(!our::revm::Match(program, L"b"));
+  REQUIRE(our::revm::Match(program, L"ab"));
+  REQUIRE(!our::revm::Match(program, L"ba"));
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_string_helpers.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_string_helpers.cpp
new file mode 100644
index 000000000..0a0f66244
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_string_helpers.cpp
@@ -0,0 +1,349 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Test `len`, the slicing of strings and `find` as used in the transpiled code.
+ *
+ * The transpiled code follows the Python implementation, since Python is
+ * the language of the meta-model specifications. Hence, the lengths and
+ * the positions count the characters (code points). The expected values have
+ * been computed with Python, and all the SDKs test against the very same cases.
+ */
+
+#include "dummy/common.hpp"
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("len('') gives 0: empty text") {
+  REQUIRE(
+    our::common::LenStr(L"")
+    == 0U
+  );
+}
+
+TEST_CASE("len('abc') gives 3: ASCII text") {
+  REQUIRE(
+    our::common::LenStr(L"abc")
+    == 3U
+  );
+}
+
+TEST_CASE("len('\303\251-') gives 2: character of two UTF-8 bytes") {
+  REQUIRE(
+    our::common::LenStr(L"\u00e9-")
+    == 2U
+  );
+}
+
+TEST_CASE("len('\360\237\230\200-') gives 2: character beyond the Basic Multilingual Plane") {
+  REQUIRE(
+    our::common::LenStr(L"\U0001f600-")
+    == 2U
+  );
+}
+
+TEST_CASE("len('a\303\251\360\237\230\200b\360\237\230\200') gives 5: mixed characters") {
+  REQUIRE(
+    our::common::LenStr(L"a\u00e9\U0001f600b\U0001f600")
+    == 5U
+  );
+}
+
+TEST_CASE("'abcde'[1:3] gives 'bc': start and end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 1, 3)
+    == L"bc"
+  );
+}
+
+TEST_CASE("'abcde'[:2] gives 'ab': no start") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 0, 2)
+    == L"ab"
+  );
+}
+
+TEST_CASE("'abcde'[3:] gives 'de': no end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 3)
+    == L"de"
+  );
+}
+
+TEST_CASE("'abcde'[:] gives 'abcde': neither start nor end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 0)
+    == L"abcde"
+  );
+}
+
+TEST_CASE("'abcde'[-2:] gives 'de': negative start counts from the end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", -2)
+    == L"de"
+  );
+}
+
+TEST_CASE("'abcde'[:-2] gives 'abc': negative end counts from the end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 0, -2)
+    == L"abc"
+  );
+}
+
+TEST_CASE("'abcde'[-4:-1] gives 'bcd': negative start and end") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", -4, -1)
+    == L"bcd"
+  );
+}
+
+TEST_CASE("'abcde'[-10:2] gives 'ab': negative start before the beginning is clamped") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", -10, 2)
+    == L"ab"
+  );
+}
+
+TEST_CASE("'abcde'[2:10] gives 'cde': end beyond the end is clamped") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 2, 10)
+    == L"cde"
+  );
+}
+
+TEST_CASE("'abcde'[10:] gives '': start beyond the end gives empty") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 10)
+    == L""
+  );
+}
+
+TEST_CASE("'abcde'[3:1] gives '': start after end gives empty") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 3, 1)
+    == L""
+  );
+}
+
+TEST_CASE("'abcde'[-1:-3] gives '': negative start after negative end gives empty") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", -1, -3)
+    == L""
+  );
+}
+
+TEST_CASE("'abcde'[5:5] gives '': start equal to end gives empty") {
+  REQUIRE(
+    our::common::SliceStr(L"abcde", 5, 5)
+    == L""
+  );
+}
+
+TEST_CASE("''[0:0] gives '': empty text") {
+  REQUIRE(
+    our::common::SliceStr(L"", 0, 0)
+    == L""
+  );
+}
+
+TEST_CASE("''[-1:] gives '': negative start on empty text") {
+  REQUIRE(
+    our::common::SliceStr(L"", -1)
+    == L""
+  );
+}
+
+TEST_CASE("''[:5] gives '': end beyond the end of empty text") {
+  REQUIRE(
+    our::common::SliceStr(L"", 0, 5)
+    == L""
+  );
+}
+
+TEST_CASE("'\303\251-x'[1:] gives '-x': after a character of two UTF-8 bytes") {
+  REQUIRE(
+    our::common::SliceStr(L"\u00e9-x", 1)
+    == L"-x"
+  );
+}
+
+TEST_CASE("'a\303\251b'[1:2] gives '\303\251': character of two UTF-8 bytes") {
+  REQUIRE(
+    our::common::SliceStr(L"a\u00e9b", 1, 2)
+    == L"\u00e9"
+  );
+}
+
+TEST_CASE("'a\360\237\230\200b'[1:2] gives '\360\237\230\200': character beyond the Basic Multilingual Plane") {
+  REQUIRE(
+    our::common::SliceStr(L"a\U0001f600b", 1, 2)
+    == L"\U0001f600"
+  );
+}
+
+TEST_CASE("'\360\237\230\200-x'[1:] gives '-x': after a character beyond the Basic Multilingual Plane") {
+  REQUIRE(
+    our::common::SliceStr(L"\U0001f600-x", 1)
+    == L"-x"
+  );
+}
+
+TEST_CASE("'a\303\251\360\237\230\200b\360\237\230\200'[-3:-1] gives '\360\237\230\200b': negative start on characters beyond ASCII") {
+  REQUIRE(
+    our::common::SliceStr(L"a\u00e9\U0001f600b\U0001f600", -3, -1)
+    == L"\U0001f600b"
+  );
+}
+
+TEST_CASE("'abcabc'.find('b') gives 1: found") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"b")
+    == 1
+  );
+}
+
+TEST_CASE("'abcabc'.find('x') gives -1: not found") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"x")
+    == -1
+  );
+}
+
+TEST_CASE("'abcabc'.find('') gives 0: empty sub") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"")
+    == 0
+  );
+}
+
+TEST_CASE("'ab'.find('abc') gives -1: sub longer than text") {
+  REQUIRE(
+    our::common::FindStr(L"ab", L"abc")
+    == -1
+  );
+}
+
+TEST_CASE("'abcabc'.find('b', 2) gives 4: found after start") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"b", 2)
+    == 4
+  );
+}
+
+TEST_CASE("'abcabc'.find('b', 5) gives -1: found only before start") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"b", 5)
+    == -1
+  );
+}
+
+TEST_CASE("'abcabc'.find('c', -1) gives 5: negative start counts from the end") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"c", -1)
+    == 5
+  );
+}
+
+TEST_CASE("'abcabc'.find('a', -3) gives 3: negative start finds the later occurrence") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"a", -3)
+    == 3
+  );
+}
+
+TEST_CASE("'abcabc'.find('a', -10) gives 0: negative start before the beginning is clamped") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"a", -10)
+    == 0
+  );
+}
+
+TEST_CASE("'abcabc'.find('', 6) gives 6: empty sub at the end") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"", 6)
+    == 6
+  );
+}
+
+TEST_CASE("'abcabc'.find('', 7) gives -1: empty sub beyond the end gives -1") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"", 7)
+    == -1
+  );
+}
+
+TEST_CASE("'abcabc'.find('c', 10) gives -1: start beyond the end gives -1") {
+  REQUIRE(
+    our::common::FindStr(L"abcabc", L"c", 10)
+    == -1
+  );
+}
+
+TEST_CASE("''.find('') gives 0: empty sub in empty text") {
+  REQUIRE(
+    our::common::FindStr(L"", L"")
+    == 0
+  );
+}
+
+TEST_CASE("''.find('', 1) gives -1: empty sub beyond the end of empty text gives -1") {
+  REQUIRE(
+    our::common::FindStr(L"", L"", 1)
+    == -1
+  );
+}
+
+TEST_CASE("''.find('x') gives -1: not found in empty text") {
+  REQUIRE(
+    our::common::FindStr(L"", L"x")
+    == -1
+  );
+}
+
+TEST_CASE("'\303\251-'.find('-') gives 1: after a character of two UTF-8 bytes") {
+  REQUIRE(
+    our::common::FindStr(L"\u00e9-", L"-")
+    == 1
+  );
+}
+
+TEST_CASE("'\360\237\230\200-'.find('-') gives 1: after a character beyond the Basic Multilingual Plane") {
+  REQUIRE(
+    our::common::FindStr(L"\U0001f600-", L"-")
+    == 1
+  );
+}
+
+TEST_CASE("'a\360\237\230\200b'.find('\360\237\230\200') gives 1: character beyond the Basic Multilingual Plane") {
+  REQUIRE(
+    our::common::FindStr(L"a\U0001f600b", L"\U0001f600")
+    == 1
+  );
+}
+
+TEST_CASE("'\360\237\230\200a\360\237\230\200a'.find('a', 2) gives 3: start after a character beyond ASCII") {
+  REQUIRE(
+    our::common::FindStr(L"\U0001f600a\U0001f600a", L"a", 2)
+    == 3
+  );
+}
+
+TEST_CASE("'\360\237\230\200a\360\237\230\200a'.find('\360\237\230\200', -2) gives 2: negative start on characters beyond ASCII") {
+  REQUIRE(
+    our::common::FindStr(L"\U0001f600a\U0001f600a", L"\U0001f600", -2)
+    == 2
+  );
+}
+
+TEST_CASE("'\303\251\360\237\230\200'.find('', 3) gives -1: start beyond the end of characters beyond ASCII") {
+  REQUIRE(
+    our::common::FindStr(L"\u00e9\U0001f600", L"", 3)
+    == -1
+  );
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_base64.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_base64.cpp
new file mode 100644
index 000000000..6e9de0510
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_base64.cpp
@@ -0,0 +1,337 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Test base64 encoding and decoding.
+ */
+
+#include "dummy/stringification.hpp"
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+std::string BytesToString(const std::vector<uint8_t>& bytes) {
+  std::string result;
+  result.resize(bytes.size());
+  for (size_t i = 0; i < bytes.size(); ++i
+    ) {
+    result[i] = bytes[i];
+  }
+  return result;
+}
+
+std::vector<uint8_t> StringToBytes(const std::string& text) {
+  std::vector<uint8_t> result;
+  result.resize(text.size());
+  for (size_t i = 0; i < text.size(); ++i
+    ) {
+    result[i] = text[i];
+  }
+  return result;
+}
+
+void AssertEncodeDecode(
+  const std::string& text,
+  const std::string& expected_encoded
+) {
+  const std::string encoded = our::stringification::Base64Encode(
+    StringToBytes(text)
+  );
+
+  REQUIRE(
+    expected_encoded
+      == encoded
+  );
+
+  our::common::expected<
+    std::vector<std::uint8_t>,
+    std::string
+  > bytes = our::stringification::Base64Decode(encoded);
+
+  REQUIRE(bytes.has_value());
+
+  REQUIRE(
+    BytesToString(bytes.value())
+      == text
+  );
+}
+
+TEST_CASE("Test '' is encoded ''") {
+  AssertEncodeDecode(
+    "",
+    ""
+  );
+}
+
+TEST_CASE("Test 'f' is encoded 'Zg=='") {
+  AssertEncodeDecode(
+    "f",
+    "Zg=="
+  );
+}
+
+TEST_CASE("Test 'fo' is encoded 'Zm8='") {
+  AssertEncodeDecode(
+    "fo",
+    "Zm8="
+  );
+}
+
+TEST_CASE("Test 'foo' is encoded 'Zm9v'") {
+  AssertEncodeDecode(
+    "foo",
+    "Zm9v"
+  );
+}
+
+TEST_CASE("Test 'foob' is encoded 'Zm9vYg=='") {
+  AssertEncodeDecode(
+    "foob",
+    "Zm9vYg=="
+  );
+}
+
+TEST_CASE("Test 'fooba' is encoded 'Zm9vYmE='") {
+  AssertEncodeDecode(
+    "fooba",
+    "Zm9vYmE="
+  );
+}
+
+TEST_CASE("Test 'foobar' is encoded 'Zm9vYmFy'") {
+  AssertEncodeDecode(
+    "foobar",
+    "Zm9vYmFy"
+  );
+}
+
+TEST_CASE("Test unexpected padding in the middle") {
+  const std::string encoded = "Zm9vYmFy";
+  for (size_t i = 0; i < encoded.size() - 1; ++i
+    ) {
+    const std::string bad_encoded(
+      encoded.substr(0, i)
+        + "="
+        + encoded.substr(i + 1, encoded.size() - i)
+    );
+
+    our::common::expected<
+      std::vector<std::uint8_t>,
+      std::string
+    > bytes = our::stringification::Base64Decode(bad_encoded);
+
+    REQUIRE(!bytes.has_value());
+
+    std::stringstream ss;
+    ss
+      << "Expected a valid character from base64-encoded string, "
+      << "but got at index " << i << ": 61 (code: 61)";
+
+    REQUIRE(
+      bytes.error()
+        == ss.str()
+    );
+  }
+}
+
+// NOTE (mristin):
+// The following checks come from: https://eprint.iacr.org/2022/361.pdf
+TEST_CASE("Test 'Hello' is encoded as 'SGVsbG8='") {
+  AssertEncodeDecode(
+    "Hello",
+    "SGVsbG8="
+  );
+}
+
+// NOTE (mristin):
+// This is not a test case, but we merely document that there is a possible
+// attack vector where different strings encode the *same* byte sequence.
+TEST_CASE("Test that our implementation suffers from padding inconsistency of 'Hello' as 'SGVsbG9='") {
+  const std::string encoded = "SGVsbG9=";
+
+  our::common::expected<
+    std::vector<std::uint8_t>,
+    std::string
+  > bytes = our::stringification::Base64Decode(encoded);
+
+  REQUIRE(bytes.has_value());
+
+  REQUIRE(
+    BytesToString(bytes.value())
+      == "Hello"
+  );
+}
+
+void AssertDecode(
+  const std::string& encoded,
+  const std::vector<std::uint8_t>& expected_decoded
+) {
+  our::common::expected<
+    std::vector<std::uint8_t>,
+    std::string
+  > bytes = our::stringification::Base64Decode(encoded);
+
+  INFO(encoded)
+  REQUIRE(bytes.has_value());
+
+  INFO(encoded)
+  REQUIRE(bytes->size() == expected_decoded.size());
+
+  for (size_t i = 0; i < bytes->size(); ++i
+    ) {
+    INFO(encoded + " is not correctly decoded at " + std::to_string(i))
+    REQUIRE(bytes->at(i) == expected_decoded[i]);
+  }
+}
+
+// NOTE (mristin):
+// The following tests have been scraped from:
+// https://github.com/rickkas7/Base64RK/blob/183d20e62b96ef9b0230c80c7a172715ca6f661e/test/unit-test/unit-test.cpp
+TEST_CASE("Test table from rickkas7/Base64RK") {
+  AssertDecode(
+    "",
+    {}
+  );
+
+  AssertDecode(
+    "HA==",
+    {28}
+  );
+
+  AssertDecode(
+    "rtA=",
+    {174, 208}
+  );
+
+  AssertDecode(
+    "MuDQ",
+    {50, 224, 208}
+  );
+
+  AssertDecode(
+    "LRLrBg==",
+    {45, 18, 235, 6}
+  );
+
+  AssertDecode(
+    "dceZ3aA=",
+    {117, 199, 153, 221, 160}
+  );
+
+  AssertDecode(
+    "jQy8MK0t",
+    {141, 12, 188, 48, 173, 45}
+  );
+
+  AssertDecode(
+    "RY+UfdUDlA==",
+    {69, 143, 148, 125, 213, 3, 148}
+  );
+
+  AssertDecode(
+    "+6KmPIGDLg0=",
+    {251, 162, 166, 60, 129, 131, 46, 13}
+  );
+
+  AssertDecode(
+    "zyjM/k1HPQiA",
+    {207, 40, 204, 254, 77, 71, 61, 8, 128}
+  );
+
+  AssertDecode(
+    "nJbVrnU7RtzSPw==",
+    {156, 150, 213, 174, 117, 59, 70, 220, 210, 63}
+  );
+
+  AssertDecode(
+    "wDatE35UGvqnBTI=",
+    {192, 54, 173, 19, 126, 84, 26, 250, 167, 5, 50}
+  );
+
+  AssertDecode(
+    "FAEPTeCNmS+6qsjj",
+    {20, 1, 15, 77, 224, 141, 153, 47, 186, 170, 200, 227}
+  );
+
+  AssertDecode(
+    "VaaCqcF1wlHuQLTkfw==",
+    {85, 166, 130, 169, 193, 117, 194, 81, 238, 64, 180, 228, 127}
+  );
+
+  AssertDecode(
+    "QYKREfdjniR1CMABweo=",
+    {65, 130, 145, 17, 247, 99, 158, 36, 117, 8, 192, 1, 193, 234}
+  );
+
+  AssertDecode(
+    "CTf9s8td7Tr8yKiRczUf",
+    {9, 55, 253, 179, 203, 93, 237, 58, 252, 200, 168, 145, 115, 53, 31}
+  );
+
+  AssertDecode(
+    "/kyMTRA0d+W64W21hiLlmesBEH4RDg0MivjmPEmAdMzP",
+    {254, 76, 140, 77, 16, 52, 119, 229, 186, 225, 109, 181, 134, 34,
+     229, 153, 235, 1, 16, 126, 17, 14, 13, 12, 138,
+     248, 230, 60, 73, 128, 116, 204, 207}
+  );
+
+  AssertDecode(
+    "m5/QqN3YcQg6iE1dVjJQWw5mCjYCnsNLKPVUsXQ269l86M1xbyHn+/aIKafJ6hRT4UOD0mH"
+    "CAfye/VSHdwH+C7bQ",
+    {155, 159, 208, 168, 221, 216, 113, 8, 58, 136, 77, 93, 86, 50, 80,
+     91, 14, 102, 10, 54, 2, 158, 195, 75, 40, 245,
+     84, 177, 116, 54, 235, 217, 124, 232, 205, 113, 111, 33, 231, 251, 246, 136, 41,
+     167, 201, 234, 20, 83, 225, 67,
+     131, 210, 97, 194, 1, 252, 158, 253, 84, 135, 119, 1, 254, 11, 182, 208}
+  );
+
+  AssertDecode(
+    "ZSsh3WyA3d00CyimeMZPAI1/t+LF6DQdiAEQG9hHlfuDXhZ2Gf/Wd1u2y+RDFli0oSq2fbfv"
+    "utgXCxGQfMmxA1NEg/k0vQIcSqzWdX7571oWzKHz6KZnlhTwPF27QznnAWbdwkyiCFlIlpL3tYbyzbMT"
+    "m0ReUtY4AW9tTpvYSQdQ8w==",
+    {101, 43, 33, 221, 108, 128, 221, 221, 52, 11, 40, 166, 120, 198,
+     79, 0, 141, 127, 183, 226, 197, 232, 52, 29, 136,
+     1, 16, 27, 216, 71, 149, 251, 131, 94, 22, 118, 25, 255, 214, 119, 91, 182, 203,
+     228, 67, 22, 88, 180, 161, 42,
+     182, 125, 183, 239, 186, 216, 23, 11, 17, 144, 124, 201, 177, 3, 83, 68, 131,
+     249, 52, 189, 2, 28, 74, 172, 214,
+     117, 126, 249, 239, 90, 22, 204, 161, 243, 232, 166, 103, 150, 20, 240, 60, 93,
+     187, 67, 57, 231, 1, 102, 221, 194,
+     76, 162, 8, 89, 72, 150, 146, 247, 181, 134, 242, 205, 179, 19, 155, 68, 94, 82,
+     214, 56, 1, 111, 109, 78, 155,
+     216, 73, 7, 80, 243}
+  );
+
+  AssertDecode(
+    "seCV0jbCe42d4GMBvXIl5vqVoZ6K4gUSg6nKgi5tZiNxx22yYon5ReOC6PZpZWHqeJcfKVo"
+    "UD/Za1ieLVjROriNfP+Lxf6Tbroz/EXh2YYOFI+d110oObkYqbgcl6ovS4CRH40Sb7L89Uwu9WDzQA"
+    "215IEepOn1wdBCZyEryWY2PGdNcs+Pft9sSNtBQ/QtMRZYEMO5JpRmFyFDPVLZA+5xM/3Dj65odv1b"
+    "ZdtszJq0Gbw43ww0t7EK0J21uBy89Z2R1N1kjQGpqKu4lRhQIgCKDOHhnfZW2gtkmZhiqby9xT44Ep1"
+    "AMrmZKgW3MDPzIX2Ez16mUv3Gb5JHrI/w1sQ==",
+    {177, 224, 149, 210, 54, 194, 123, 141, 157, 224, 99, 1, 189,
+     114, 37, 230, 250, 149, 161, 158, 138, 226, 5, 18,
+     131, 169, 202, 130, 46, 109, 102, 35, 113, 199, 109, 178, 98, 137, 249, 69, 227,
+     130, 232, 246, 105, 101, 97, 234,
+     120, 151, 31, 41, 90, 20, 15, 246, 90, 214, 39, 139, 86, 52, 78, 174, 35, 95, 63,
+     226, 241, 127, 164, 219, 174,
+     140, 255, 17, 120, 118, 97, 131, 133, 35, 231, 117, 215, 74, 14, 110, 70, 42,
+     110, 7, 37, 234, 139, 210, 224, 36,
+     71, 227, 68, 155, 236, 191, 61, 83, 11, 189, 88, 60, 208, 3, 109, 121, 32, 71,
+     169, 58, 125, 112, 116, 16, 153,
+     200, 74, 242, 89, 141, 143, 25, 211, 92, 179, 227, 223, 183, 219, 18, 54, 208,
+     80, 253, 11, 76, 69, 150, 4, 48,
+     238, 73, 165, 25, 133, 200, 80, 207, 84, 182, 64, 251, 156, 76, 255, 112, 227,
+     235, 154, 29, 191, 86, 217, 118,
+     219, 51, 38, 173, 6, 111, 14, 55, 195, 13, 45, 236, 66, 180, 39, 109, 110, 7,
+     47, 61, 103, 100, 117, 55, 89, 35,
+     64, 106, 106, 42, 238, 37, 70, 20, 8, 128, 34, 131, 56, 120, 103, 125, 149,
+     182, 130, 217, 38, 102, 24, 170, 111,
+     47, 113, 79, 142, 4, 167, 80, 12, 174, 102, 74, 129, 109, 204, 12, 252, 200,
+     95, 97, 51, 215, 169, 148, 191, 113,
+     155, 228, 145, 235, 35, 252, 53, 177}
+  );
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_of_enums.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_of_enums.cpp
new file mode 100644
index 000000000..18635acd3
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_stringification_of_enums.cpp
@@ -0,0 +1,84 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/stringification.hpp"
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("Test ModelType round-trip") {
+  REQUIRE(
+    our::types::ModelType::kSomeItem
+    == our::stringification::MustModelTypeFromString(
+      "SomeItem"
+    )
+  );
+
+  REQUIRE(
+    our::stringification::to_string(
+      our::types::ModelType::kSomeItem
+    )
+    == "SomeItem"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kSpecialItem
+    == our::stringification::MustModelTypeFromString(
+      "SpecialItem"
+    )
+  );
+
+  REQUIRE(
+    our::stringification::to_string(
+      our::types::ModelType::kSpecialItem
+    )
+    == "SpecialItem"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kContainer
+    == our::stringification::MustModelTypeFromString(
+      "Container"
+    )
+  );
+
+  REQUIRE(
+    our::stringification::to_string(
+      our::types::ModelType::kContainer
+    )
+    == "Container"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kWrapper
+    == our::stringification::MustModelTypeFromString(
+      "Wrapper"
+    )
+  );
+
+  REQUIRE(
+    our::stringification::to_string(
+      our::types::ModelType::kWrapper
+    )
+    == "Wrapper"
+  );
+}
+
+TEST_CASE("Test failure on ModelType") {
+  CHECK(
+    !our::stringification::ModelTypeFromString(
+      "Totally utterly invalid"
+    ).has_value()
+  );
+
+  REQUIRE_THROWS_WITH(
+    our::stringification::MustModelTypeFromString(
+      "Totally utterly invalid"
+    ),
+    "Unexpected ModelType literal: Totally utterly invalid"
+  );
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_verification.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_verification.cpp
new file mode 100644
index 000000000..bd9d7d7fb
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_verification.cpp
@@ -0,0 +1,324 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_xmlization.hpp"
+
+#include <dummy/verification.hpp>
+#include <dummy/xmlization.hpp>
+
+#include <catch2/catch.hpp>
+
+#include <fstream>
+
+namespace our = dummy;
+
+void AssertNoVerificationError(
+  const std::filesystem::path& xml_path
+) {
+  std::shared_ptr<
+    our::types::IClass
+  > instance(
+    test::common::xmlization::MustDeserializeFile(xml_path)
+  );
+
+  std::vector<std::string> error_messages;
+  for (
+    const our::verification::Error &error
+    : our::verification::RecursiveVerification(instance)
+  ) {
+    error_messages.emplace_back(
+      our::common::Concat(
+        our::common::WstringToUtf8(error.path.ToWstring()),
+        ": ",
+        our::common::WstringToUtf8(error.cause)
+      )
+    );
+  }
+
+  if (!error_messages.empty()) {
+    std::vector<std::string> parts;
+    parts.emplace_back("Expected no error messages from ");
+    parts.emplace_back(xml_path.string());
+    parts.emplace_back(", but got:\n");
+    parts.emplace_back(test::common::JoinStrings(error_messages, "\n"));
+
+    INFO(test::common::JoinStrings(parts, ""))
+    CHECK(error_messages.empty());
+  }
+}
+
+const std::filesystem::path& DetermineXmlDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "Xml";
+  }
+
+  return *result;
+}
+
+const std::filesystem::path& DetermineErrorDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "VerificationError";
+  }
+
+  return *result;
+}
+
+void AssertVerificationFailure(
+  const std::filesystem::path& path,
+  const std::filesystem::path& error_path
+) {
+  std::ifstream ifs(path, std::ios::binary);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(
+    ifs
+  );
+
+  if (!deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Expected to de-serialize ",
+        path.string(),
+        ", but the de-serialization failed: ",
+        our::common::WstringToUtf8(deserialized.error().path.ToWstring()),
+        our::common::WstringToUtf8(deserialized.error().cause)
+      )
+    )
+    REQUIRE(!deserialized.has_value());
+  }
+
+  std::vector<std::string> error_messages;
+  for (
+    const our::verification::Error& error
+    : our::verification::RecursiveVerification(deserialized.value())
+    ) {
+    error_messages.emplace_back(
+      our::common::Concat(
+        our::common::WstringToUtf8(error.path.ToWstring()),
+        ": ",
+        our::common::WstringToUtf8(error.cause)
+      )
+    );
+  }
+
+  if (error_messages.empty()) {
+    INFO(
+      our::common::Concat(
+        "Expected error messages from ",
+        path.string(),
+        ", but got none"
+      )
+    )
+    REQUIRE(!error_messages.empty());
+  }
+
+  const std::string joined_error_messages = test::common::JoinStrings(
+    error_messages,
+    "\n"
+  );
+
+  test::common::AssertContentEqualsExpectedOrRecord(
+    joined_error_messages,
+    error_path
+  );
+}
+
+TEST_CASE("Test verification of a valid SomeItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "someItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertNoVerificationError(path);
+  }
+}
+
+TEST_CASE("Test verification of invalid cases for SomeItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Invalid"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "someItem",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+            / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+          / (path.filename().string() + ".errors")
+      );
+
+      AssertVerificationFailure(path, error_path);
+    }
+  }
+}
+
+TEST_CASE("Test verification of a valid SpecialItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "specialItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertNoVerificationError(path);
+  }
+}
+
+TEST_CASE("Test verification of invalid cases for SpecialItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Invalid"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "specialItem",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+            / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+          / (path.filename().string() + ".errors")
+      );
+
+      AssertVerificationFailure(path, error_path);
+    }
+  }
+}
+
+TEST_CASE("Test verification of a valid Container") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "container",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertNoVerificationError(path);
+  }
+}
+
+TEST_CASE("Test verification of invalid cases for Container") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Invalid"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "container",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+            / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+          / (path.filename().string() + ".errors")
+      );
+
+      AssertVerificationFailure(path, error_path);
+    }
+  }
+}
+
+TEST_CASE("Test verification of a valid Wrapper") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "wrapper",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path& path : paths) {
+    AssertNoVerificationError(path);
+  }
+}
+
+TEST_CASE("Test verification of invalid cases for Wrapper") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Invalid"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "wrapper",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+            / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+          / (path.filename().string() + ".errors")
+      );
+
+      AssertVerificationFailure(path, error_path);
+    }
+  }
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_wstringification_of_enums.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_wstringification_of_enums.cpp
new file mode 100644
index 000000000..4da059f3c
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_wstringification_of_enums.cpp
@@ -0,0 +1,84 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "dummy/wstringification.hpp"
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("Test ModelType round-trip") {
+  REQUIRE(
+    our::types::ModelType::kSomeItem
+    == our::wstringification::MustModelTypeFromWstring(
+      L"SomeItem"
+    )
+  );
+
+  REQUIRE(
+    our::wstringification::to_wstring(
+      our::types::ModelType::kSomeItem
+    )
+    == L"SomeItem"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kSpecialItem
+    == our::wstringification::MustModelTypeFromWstring(
+      L"SpecialItem"
+    )
+  );
+
+  REQUIRE(
+    our::wstringification::to_wstring(
+      our::types::ModelType::kSpecialItem
+    )
+    == L"SpecialItem"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kContainer
+    == our::wstringification::MustModelTypeFromWstring(
+      L"Container"
+    )
+  );
+
+  REQUIRE(
+    our::wstringification::to_wstring(
+      our::types::ModelType::kContainer
+    )
+    == L"Container"
+  );
+
+  REQUIRE(
+    our::types::ModelType::kWrapper
+    == our::wstringification::MustModelTypeFromWstring(
+      L"Wrapper"
+    )
+  );
+
+  REQUIRE(
+    our::wstringification::to_wstring(
+      our::types::ModelType::kWrapper
+    )
+    == L"Wrapper"
+  );
+}
+
+TEST_CASE("Test failure on ModelType") {
+  CHECK(
+    !our::wstringification::ModelTypeFromWstring(
+      L"Totally utterly invalid"
+    ).has_value()
+  );
+
+  REQUIRE_THROWS_WITH(
+    our::wstringification::MustModelTypeFromWstring(
+      L"Totally utterly invalid"
+    ),
+    "Unexpected ModelType literal: Totally utterly invalid"
+  );
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_x_or_default.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_x_or_default.cpp
new file mode 100644
index 000000000..08d0b32cd
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_x_or_default.cpp
@@ -0,0 +1,24 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_examples.hpp"
+
+#include <dummy/stringification.hpp>
+#include <dummy/types.hpp>
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+const std::filesystem::path& DetermineLogDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "XxxOrDefault";
+  }
+
+  return *result;
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_dispatch.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_dispatch.cpp
new file mode 100644
index 000000000..357e71770
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_dispatch.cpp
@@ -0,0 +1,149 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common_examples.hpp"
+
+#include <dummy/xmlization.hpp>
+
+#include <catch2/catch.hpp>
+
+namespace our = dummy;
+
+TEST_CASE("Test the round-trip of an expected IItem") {
+  const std::shared_ptr<
+    our::types::ISomeItem
+  > original_instance(
+    test::common::examples::LoadMinSomeItem()
+  );
+
+  std::stringstream ss;
+  our::xmlization::Serialize(
+    *original_instance,
+    {},
+    ss
+  );
+
+  const std::string original_xml = ss.str();
+
+  ss.seekp(0);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(
+    ss
+  );
+
+  if (!deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to make the round-trip Serialize-Deserialize "
+        "a minimal instance of ISomeItem: ",
+        our::common::WstringToUtf8(
+          deserialized.error().path.ToWstring()
+        ),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().cause
+        )
+      )
+    )
+    REQUIRE(deserialized.has_value());
+  }
+
+  std::shared_ptr<
+    our::types::IItem
+  > abstract = std::dynamic_pointer_cast<
+    our::types::IItem
+  >(deserialized.value());
+
+  std::stringstream another_ss;
+  our::xmlization::Serialize(
+    *abstract,
+    {},
+    another_ss
+  );
+
+  INFO(
+    "Original XML and the XML at the end of "
+    "the chain Serialize-Deserialize-Serialize for "
+    "a minimal instance of ISomeItem "
+    "serialized as IItem "
+    "must coincide"
+  )
+  REQUIRE(
+    original_xml
+    == another_ss.str()
+  );
+}
+
+TEST_CASE("Test the round-trip of an expected ISomeItem") {
+  const std::shared_ptr<
+    our::types::ISpecialItem
+  > original_instance(
+    test::common::examples::LoadMinSpecialItem()
+  );
+
+  std::stringstream ss;
+  our::xmlization::Serialize(
+    *original_instance,
+    {},
+    ss
+  );
+
+  const std::string original_xml = ss.str();
+
+  ss.seekp(0);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(
+    ss
+  );
+
+  if (!deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Failed to make the round-trip Serialize-Deserialize "
+        "a minimal instance of ISpecialItem: ",
+        our::common::WstringToUtf8(
+          deserialized.error().path.ToWstring()
+        ),
+        ": ",
+        our::common::WstringToUtf8(
+          deserialized.error().cause
+        )
+      )
+    )
+    REQUIRE(deserialized.has_value());
+  }
+
+  std::shared_ptr<
+    our::types::ISomeItem
+  > abstract = std::dynamic_pointer_cast<
+    our::types::ISomeItem
+  >(deserialized.value());
+
+  std::stringstream another_ss;
+  our::xmlization::Serialize(
+    *abstract,
+    {},
+    another_ss
+  );
+
+  INFO(
+    "Original XML and the XML at the end of "
+    "the chain Serialize-Deserialize-Serialize for "
+    "a minimal instance of ISpecialItem "
+    "serialized as ISomeItem "
+    "must coincide"
+  )
+  REQUIRE(
+    original_xml
+    == another_ss.str()
+  );
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_of_concrete_classes.cpp b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_of_concrete_classes.cpp
new file mode 100644
index 000000000..0bbfe3c79
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/expected_output/test/test_xmlization_of_concrete_classes.cpp
@@ -0,0 +1,349 @@
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+#include "./common.hpp"
+#include "./common_xmlization.hpp"
+
+#include <dummy/xmlization.hpp>
+
+#include <catch2/catch.hpp>
+
+#include <fstream>
+
+namespace our = dummy;
+
+void AssertRoundTrip(
+  const std::filesystem::path& path
+) {
+  std::shared_ptr<
+    our::types::IClass
+  > deserialized(
+    test::common::xmlization::MustDeserializeFile(path)
+  );
+
+  std::stringstream ss;
+  our::xmlization::Serialize(*deserialized, {}, ss);
+
+  std::string expected_xml = test::common::MustReadString(path);
+
+  INFO(our::common::Concat("XML round-trip on ", path.string()))
+  REQUIRE(
+    test::common::xmlization::CanonicalizeXml(expected_xml)
+      == test::common::xmlization::CanonicalizeXml(ss.str())
+  );
+}
+
+void AssertDeserializationFailure(
+  const std::filesystem::path& path,
+  const std::filesystem::path& error_path
+) {
+  std::ifstream ifs(path, std::ios::binary);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(
+    ifs
+  );
+
+  if (deserialized.has_value()) {
+    INFO(
+      our::common::Concat(
+        "Expected the de-serialization to fail on ",
+        path.string(),
+        ", but the de-serialization succeeded"
+      )
+    )
+    REQUIRE(!deserialized.has_value());
+  }
+
+  test::common::AssertContentEqualsExpectedOrRecord(
+    our::common::Concat(
+      our::common::WstringToUtf8(
+        deserialized.error().path.ToWstring()
+      ),
+      ": ",
+      our::common::WstringToUtf8(
+        deserialized.error().cause
+      )
+    ),
+    error_path
+  );
+}
+
+const std::filesystem::path& DetermineXmlDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "Xml";
+  }
+
+  return *result;
+}
+
+const std::filesystem::path& DetermineErrorDir() {
+  static our::common::optional<std::filesystem::path> result;
+  if (!result.has_value()) {
+    result = test::common::DetermineTestDataDir() / "XmlizationError";
+  }
+
+  return *result;
+}
+
+TEST_CASE("Test the round-trip of an expected SomeItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "someItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path &path : paths) {
+    AssertRoundTrip(path);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected SomeItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "someItem",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure(
+        path,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected SpecialItem") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "specialItem",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path &path : paths) {
+    AssertRoundTrip(path);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected SpecialItem") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "specialItem",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure(
+        path,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected Container") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "container",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path &path : paths) {
+    AssertRoundTrip(path);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected Container") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "container",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure(
+        path,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the round-trip of an expected Wrapper") {
+  const std::deque<std::filesystem::path> paths(
+    test::common::FindFilesBySuffixRecursively(
+      DetermineXmlDir()
+        / "Expected"
+        / "wrapper",
+      ".xml"
+    )
+  );
+
+  for (const std::filesystem::path &path : paths) {
+    AssertRoundTrip(path);
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on an unexpected Wrapper") {
+  for (
+    const std::filesystem::path& causeDir
+    : test::common::ListSubdirectories(
+      DetermineXmlDir()
+        / "Unexpected"
+        / "Unserializable"
+    )
+  ) {
+    for (
+      const std::filesystem::path& path
+      : test::common::FindFilesBySuffixRecursively(
+        causeDir / "wrapper",
+        ".xml"
+      )
+    ) {
+      const std::filesystem::path parent(
+        (
+          DetermineErrorDir()
+          / std::filesystem::relative(path, DetermineXmlDir())
+        ).parent_path()
+      );
+
+      const std::filesystem::path error_path(
+        parent
+        / (path.filename().string() + ".error")
+      );
+
+      AssertDeserializationFailure(
+        path,
+        error_path
+      );
+    }
+  }
+}
+
+TEST_CASE("Test the de-serialization failure on a duplicate property") {
+  const std::filesystem::path path(
+    DetermineXmlDir()
+      / "Expected"
+      / "someItem"
+      / "minimal.xml"
+  );
+
+  const std::string original(test::common::MustReadString(path));
+
+  // We cut the element of the property out of the recorded example and put it
+  // in a second time, just before the closing tag of the instance.
+  const std::size_t start(
+    original.find("<name>")
+  );
+
+  std::string property;
+  if (start != std::string::npos) {
+    const std::size_t end(
+      original.find("</name>", start)
+    );
+    property = original.substr(start, end + 7 - start);
+  } else {
+    // The element is written self-closing in the example, an empty list being
+    // the usual reason. We write that very element out ourselves.
+    property = "<name/>";
+  }
+
+  const std::size_t insertion_index(
+    original.rfind("</someItem>")
+  );
+
+  INFO(our::common::Concat("Looking for </someItem> in ", path.string()))
+  REQUIRE(insertion_index != std::string::npos);
+
+  const std::string broken(
+    original.substr(0, insertion_index)
+      + property
+      + original.substr(insertion_index)
+  );
+
+  std::istringstream iss(broken);
+
+  our::common::expected<
+    std::shared_ptr<our::types::IClass>,
+    our::xmlization::DeserializationError
+  > deserialized = our::xmlization::From(iss);
+
+  INFO(our::common::Concat("De-serializing: ", broken))
+  REQUIRE(!deserialized.has_value());
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/cpp/expected/variance_of_containers/input/snippets/namespace.txt b/dev/test_data/main/cpp/expected/variance_of_containers/input/snippets/namespace.txt
new file mode 100644
index 000000000..2995a4d0e
--- /dev/null
+++ b/dev/test_data/main/cpp/expected/variance_of_containers/input/snippets/namespace.txt
@@ -0,0 +1 @@
+dummy
\ No newline at end of file
diff --git a/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/return_code.json b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/return_code.json
new file mode 100644
index 000000000..56a6051ca
--- /dev/null
+++ b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/return_code.json
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/stderr.txt b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/stderr.txt
new file mode 100644
index 000000000..322f3d6f5
--- /dev/null
+++ b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/stderr.txt
@@ -0,0 +1,2 @@
+Failed to generate include/dummy/verification.hpp based on <path to meta_model.py>:
+* At line 35 and column 17: The public verification function 'items_are_named' has generic sequences, so we generate it in C++ as a template defined in the header. However, it calls the internal verification function '_is_named', which is declared only in the implementation file. Please make '_is_named' public, or 'items_are_named' internal.
diff --git a/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/stdout.txt b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/expected_output/stdout.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/input/snippets/namespace.txt b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/input/snippets/namespace.txt
new file mode 100644
index 000000000..2995a4d0e
--- /dev/null
+++ b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/input/snippets/namespace.txt
@@ -0,0 +1 @@
+dummy
\ No newline at end of file
diff --git a/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/meta_model.py b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/meta_model.py
new file mode 100644
index 000000000..3ea7f3b94
--- /dev/null
+++ b/dev/test_data/main/cpp/unexpected/public_generic_verification_calls_internal/meta_model.py
@@ -0,0 +1,50 @@
+"""
+Test that a public generic verification function can not call an internal one.
+
+The public generic verification functions are templates defined in the C++ header,
+while the internal verification functions are declared only in the implementation
+file.
+"""
+
+from typing import List, Sequence
+
+from icontract import DBC, invariant
+
+
+@abstract
+@serialization(with_model_type=True)
+class Item(DBC):
+    name: str
+
+    def __init__(self, name: str) -> None:
+        self.name = name
+
+
+class Some_item(Item, DBC):
+    def __init__(self, name: str) -> None:
+        Item.__init__(self, name)
+
+
+@verification
+def _is_named(item: Item) -> bool:
+    return len(item.name) > 0
+
+
+@verification
+def items_are_named(items: Sequence[Item]) -> bool:
+    return all(_is_named(item) for item in items)
+
+
+@invariant(
+    lambda self: items_are_named(self.items),
+    "The items must be named.",
+)
+class Container(DBC):
+    items: List[Some_item]
+
+    def __init__(self, items: List[Some_item]) -> None:
+        self.items = items
+
+
+__version__ = "dummy"
+__xml_namespace__ = "https://dummy.com"
diff --git a/dev/test_data/main/csharp/expected/annotated_assignments/expected_output/dummy/verification.cs b/dev/test_data/main/csharp/expected/annotated_assignments/expected_output/dummy/verification.cs
index ba92418a8..b7bef033d 100644
--- a/dev/test_data/main/csharp/expected/annotated_assignments/expected_output/dummy/verification.cs
+++ b/dev/test_data/main/csharp/expected/annotated_assignments/expected_output/dummy/verification.cs
@@ -34,8 +34,11 @@ public static class Verification
         /// <summary>
         /// Check an optional class declared with <c>None</c> and assigned in a loop.
         /// </summary>
+        /// <remarks>
+        /// The argument parents is declared as the covariant IReadOnlyList&lt;IParent&gt; instead of the invariant List&lt;IParent&gt; so that the lists of the descendants of IParent can be passed without a copy.
+        /// </remarks>
         public static bool FirstChildAIsSmall(
-            List<IParent> parents
+            IReadOnlyList<IParent> parents
         )
         {
             Our.IChildA? found = null;
@@ -91,9 +94,12 @@ public static bool TextIsAllowedUnlessLong(
         /// <summary>
         /// Check a non-optional variable declared wider than its value.
         /// </summary>
+        /// <remarks>
+        /// The argument parents is declared as the covariant IReadOnlyList&lt;IParent&gt; instead of the invariant List&lt;IParent&gt; so that the lists of the descendants of IParent can be passed without a copy.
+        /// </remarks>
         public static bool LastChildBIsNotZero(
             IParent parent,
-            List<IParent> parents
+            IReadOnlyList<IParent> parents
         )
         {
             Our.IParent last = parent;
@@ -374,9 +380,9 @@ IParent parent
         )
         {
             long limit = 1000;
-            string label = text;
-            string? maybeText = optionalText;
-            List<string> allTexts = texts;
+            var label = text;
+            var maybeText = optionalText;
+            var allTexts = texts;
             HashSet<string> seen = new HashSet<string>();
             seen.Add(text);
             HashSet<string> reservedSeen = (
@@ -385,7 +391,7 @@ IParent parent
                 text,
                 number
             );
-            Our.IParent basE = parent;
+            var basE = parent;
             if (
                 reservedSeen.Count > 0
                 || Common.StringHelpers.Len(label) > limit
diff --git a/dev/test_data/main/csharp/expected/if_statements/expected_output/dummy/verification.cs b/dev/test_data/main/csharp/expected/if_statements/expected_output/dummy/verification.cs
index 7a2f5fa69..a08dfbbe8 100644
--- a/dev/test_data/main/csharp/expected/if_statements/expected_output/dummy/verification.cs
+++ b/dev/test_data/main/csharp/expected/if_statements/expected_output/dummy/verification.cs
@@ -296,8 +296,11 @@ public static bool NarrowingAfterTheOnlyCompletingBranch(
         /// <summary>
         /// Check the narrowing after the <c>continue</c> and the early return in a loop.
         /// </summary>
+        /// <remarks>
+        /// The argument parents is declared as the covariant IReadOnlyList&lt;IParent&gt; instead of the invariant List&lt;IParent&gt; so that the lists of the descendants of IParent can be passed without a copy.
+        /// </remarks>
         public static bool ChildAsHaveTexts(
-            List<IParent> parents
+            IReadOnlyList<IParent> parents
         )
         {
             foreach (var parent in parents)
@@ -321,8 +324,11 @@ List<IParent> parents
         /// <summary>
         /// Check the narrowing after the <c>continue</c> in a loop with a <c>break</c>.
         /// </summary>
+        /// <remarks>
+        /// The argument parents is declared as the covariant IReadOnlyList&lt;IParent&gt; instead of the invariant List&lt;IParent&gt; so that the lists of the descendants of IParent can be passed without a copy.
+        /// </remarks>
         public static bool TextsBeforeContainerAreShort(
-            List<IParent> parents
+            IReadOnlyList<IParent> parents
         )
         {
             long total = 0;
@@ -360,9 +366,12 @@ IParent parent
         /// <summary>
         /// Check the narrowing of a variable to a class by the assigned value.
         /// </summary>
+        /// <remarks>
+        /// The argument parents is declared as the covariant IReadOnlyList&lt;IParent&gt; instead of the invariant List&lt;IParent&gt; so that the lists of the descendants of IParent can be passed without a copy.
+        /// </remarks>
         public static bool LastChildAIsSmall(
             IParent parent,
-            List<IParent> parents
+            IReadOnlyList<IParent> parents
         )
         {
             var last = parent;
diff --git a/dev/test_data/main/csharp/expected/list_of_classes/expected_output/dummy/verification.cs b/dev/test_data/main/csharp/expected/list_of_classes/expected_output/dummy/verification.cs
index 2b908b28e..dac0d3bcf 100644
--- a/dev/test_data/main/csharp/expected/list_of_classes/expected_output/dummy/verification.cs
+++ b/dev/test_data/main/csharp/expected/list_of_classes/expected_output/dummy/verification.cs
@@ -66,11 +66,16 @@ List<ISimple> simples
         /// Give the instances of <see cref="Our.SomeItem" /> among <paramref name="items" />.
         /// </summary>
         /// <remarks>
+        /// <para>
         /// The appended items are narrowed down to <see cref="Our.SomeItem" />, while the list
         /// holds <see cref="Our.IAbstractItem" />'s.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IAbstractItem&gt; instead of the invariant List&lt;IAbstractItem&gt; so that the lists of the descendants of IAbstractItem can be passed without a copy.
+        /// </para>
         /// </remarks>
         public static List<IAbstractItem> SomeItemsOf(
-            List<IAbstractItem> items
+            IReadOnlyList<IAbstractItem> items
         )
         {
             List<Our.IAbstractItem> result = new List<Our.IAbstractItem>();
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/Common.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/Common.cs
new file mode 100644
index 000000000..13511cd53
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/Common.cs
@@ -0,0 +1,156 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy; // renamed
+
+using System.Collections.Generic; // can't alias
+using System.Linq; // can't alias
+using NUnit.Framework; // can't alias
+
+namespace dummy.Tests
+{
+    /// <summary>
+    /// Provide common functionality to be re-used across different tests
+    /// such as reading of environment variables.
+    /// </summary>
+    public static class Common
+    {
+        public static readonly string RecordModeEnvironmentVariableName = (
+            "DUMMY_TESTS_RECORD_MODE"
+        );
+
+        // NOTE (mristin):
+        // It is tedious to record manually all the expected error messages.
+        // Therefore we include this variable to steer the automatic recording.
+        // We intentionally inter-twine the recording code with the test code
+        // to keep them close to each other so that they are easier to maintain.
+        public static readonly bool RecordMode = (
+            System.Environment.GetEnvironmentVariable(
+                RecordModeEnvironmentVariableName
+            )?.ToLower()
+                == "true"
+            || System
+                .Environment.GetEnvironmentVariable(RecordModeEnvironmentVariableName)
+                ?.ToLower() == "on"
+            || System
+                .Environment.GetEnvironmentVariable(RecordModeEnvironmentVariableName)
+                ?.ToLower() == "1"
+            || System
+                .Environment.GetEnvironmentVariable(RecordModeEnvironmentVariableName)
+                ?.ToLower() == "yes"
+        );
+
+        public static readonly string TestDataDir = (
+            System.Environment.GetEnvironmentVariable(
+                "DUMMY_TESTS_TEST_DATA_DIR"
+            )
+            ?? throw new System.InvalidOperationException(
+                "The path to the test data directory is missing in the environment: "
+                    + "DUMMY_TESTS_TEST_DATA_DIR"
+            )
+        );
+
+        /// <summary>
+        /// Find the first instance of <typeparamref name="T"/>
+        /// in the <paramref name="container" />,
+        /// including the <paramref name="container" /> itself.
+        /// </summary>
+        public static T MustFind<T>(Our.IClass container)
+            where T : Our.IClass
+        {
+            var instance = (
+                (container is T)
+                    ? container
+                    : container.Descend().First(something => something is T)
+                    ?? throw new System.InvalidOperationException(
+                            $"No instance of {nameof(T)} could be found"
+                        )
+            );
+
+            return (T)instance;
+        }
+
+        public static void AssertNoVerificationErrors(
+            List<Our.Reporting.Error> errors,
+            string path
+        )
+        {
+            if (errors.Count > 0)
+            {
+                var builder = new System.Text.StringBuilder();
+                builder.Append(
+                    $"Expected no errors when verifying the instance de-serialized from {path}, "
+                        + $"but got {errors.Count} error(s):\n"
+                );
+                for (var i = 0; i < errors.Count; i++)
+                {
+                    builder.Append(
+                        $"Error {i + 1}:\n"
+                            + $"{Reporting.GenerateJsonPath(errors[i].PathSegments)}: "
+                            + $"{errors[i].Cause}\n"
+                    );
+                }
+
+                Assert.Fail(builder.ToString());
+            }
+        }
+
+        public static void AssertEqualsExpectedOrRerecordVerificationErrors(
+            List<Our.Reporting.Error> errors,
+            string path
+        )
+        {
+            if (errors.Count == 0)
+            {
+                Assert.Fail(
+                    $"Expected at least one verification error when verifying {path}, "
+                        + "but got none"
+                );
+            }
+
+            string got = string.Join(
+                ";\n",
+                errors.Select(error =>
+                    $"{Reporting.GenerateJsonPath(error.PathSegments)}: {error.Cause}"
+                )
+            );
+
+            string errorsPath = path + ".errors";
+            if (RecordMode)
+            {
+                System.IO.File.WriteAllText(errorsPath, got);
+            }
+            else
+            {
+                if (!System.IO.File.Exists(errorsPath))
+                {
+                    throw new System.IO.FileNotFoundException(
+                        "The file with the recorded errors does not "
+                            + $"exist: {errorsPath}; maybe you want to set "
+                            + "the environment variable "
+                            + $"{Our.Tests.Common.RecordModeEnvironmentVariableName}?"
+                    );
+                }
+
+                string expected = System.IO.File.ReadAllText(errorsPath);
+                Assert.AreEqual(
+                    expected.Replace("\r\n", "\n"),
+                    got.Replace("\r\n", "\n"),
+                    $"The expected verification errors do not match the actual ones for the file {path}"
+                );
+            }
+        }
+
+        public static string Trace(Our.IClass instance)
+        {
+            return instance.GetType().Name;
+        }
+    }  // public static class Common
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJson.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJson.cs
new file mode 100644
index 000000000..a9b32101f
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJson.cs
@@ -0,0 +1,222 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+    
+using Our = dummy; // renamed
+
+using FileMode = System.IO.FileMode;
+using FileStream = System.IO.FileStream;
+using JsonException = System.Text.Json.JsonException;
+using Nodes = System.Text.Json.Nodes;
+
+using System.Collections.Generic; // can't alias
+using System.Linq; // can't alias
+
+namespace dummy.Tests
+{
+    public static class CommonJson
+    {
+    public static Nodes.JsonNode ReadFromFile(string path)
+    {
+        using var stream = new FileStream(path, FileMode.Open);
+        Nodes.JsonNode? node;
+        try
+        {
+            node = Nodes.JsonNode.Parse(stream);
+        }
+        catch (JsonException exception)
+        {
+            throw new System.InvalidOperationException(
+                $"Expected the file to be a valid JSON, but it was not: {path}; "
+                    + $"exception was: {exception}"
+            );
+        }
+
+        if (node is null)
+        {
+            throw new System.InvalidOperationException(
+                "Expected the file to be a non-null JSON value, " + $"but it was null: {path}"
+            );
+        }
+
+        return node;
+    }
+
+    /// <summary>
+    /// Serialize <paremref name="something" /> to a uniform JSON text
+    /// such that we can use it for comparisons in the tests.
+    /// </summary>
+    public static Nodes.JsonNode ToJson(object something)
+    {
+        switch (something)
+        {
+            case bool aBool:
+                return Nodes.JsonValue.Create(aBool);
+            case long aLong:
+                return Nodes.JsonValue.Create(aLong);
+            case double aDouble:
+                return Nodes.JsonValue.Create(aDouble);
+            case string aString:
+                return Nodes.JsonValue.Create(aString)
+                    ?? throw new System.InvalidOperationException(
+                        $"Could not convert {something} " + "to a JSON string"
+                    );
+            case byte[] someBytes:
+                return Nodes.JsonValue.Create(System.Convert.ToBase64String(someBytes))
+                    ?? throw new System.InvalidOperationException(
+                        $"Could not convert {something} to " + "a base64-encoded JSON string"
+                    );
+            case Our.IClass instance:
+                return Our.Jsonization.Serialize.ToJsonObject(instance);
+            default:
+                throw new System.ArgumentException(
+                    $"The conversion of type {something.GetType()} "
+                        + $"to a JSON node has not been defined: {something}"
+                );
+        }
+    }
+
+    /// <summary>
+    /// Infer the node kind of the JSON node.
+    /// </summary>
+    /// <remarks>
+    /// This function is necessary since NET6 does not fully support node kinds yet.
+    /// See:
+    /// <ul>
+    /// <li>https://github.com/dotnet/runtime/issues/53406</li>
+    /// <li>https://github.com/dotnet/runtime/issues/55827</li>
+    /// <li>https://github.com/dotnet/runtime/issues/56592</li>
+    /// </ul>
+    /// </remarks>
+    private static string GetNodeKind(Nodes.JsonNode node)
+    {
+        switch (node)
+        {
+            case Nodes.JsonArray _:
+                return "array";
+            case Nodes.JsonObject _:
+                return "object";
+            case Nodes.JsonValue _:
+                return "value";
+            default:
+                throw new System.InvalidOperationException(
+                    $"Unhandled JsonNode: {node.GetType()}"
+                );
+        }
+    }
+
+    public static void CheckJsonNodesEqual(
+        Nodes.JsonNode that,
+        Nodes.JsonNode other,
+        out Reporting.Error? error
+    )
+    {
+        error = null;
+
+        var thatNodeKind = GetNodeKind(that);
+        var otherNodeKind = GetNodeKind(other);
+
+        if (thatNodeKind != otherNodeKind)
+        {
+            error = new Reporting.Error(
+                $"Mismatch in node kinds : {thatNodeKind} != {otherNodeKind}"
+            );
+            return;
+        }
+
+        switch (that)
+        {
+            case Nodes.JsonArray thatArray:
+                {
+                    var otherArray = (other as Nodes.JsonArray)!;
+                    if (thatArray.Count != otherArray.Count)
+                    {
+                        error = new Reporting.Error(
+                            $"Unequal array lengths: {thatArray.Count} != {otherArray.Count}"
+                        );
+                        return;
+                    }
+
+                    for (int i = 0; i < thatArray.Count; i++)
+                    {
+                        CheckJsonNodesEqual(thatArray[i]!, otherArray[i]!, out error);
+                        if (error != null)
+                        {
+                            error.PrependSegment(new Reporting.IndexSegment(i));
+                            return;
+                        }
+                    }
+
+                    break;
+                }
+            case Nodes.JsonObject thatObject:
+                {
+                    var thatDictionary = thatObject as IDictionary<string, Nodes.JsonNode>;
+                    var otherDictionary = (other as IDictionary<string, Nodes.JsonNode>)!;
+
+                    var thatKeys = thatDictionary.Keys.ToList();
+                    thatKeys.Sort();
+
+                    var otherKeys = otherDictionary.Keys.ToList();
+                    otherKeys.Sort();
+
+                    if (!thatKeys.SequenceEqual(otherKeys))
+                    {
+                        error = new Reporting.Error(
+                            "Objects with different properties: "
+                                + $"{string.Join(", ", thatKeys)} != "
+                                + $"{string.Join(", ", otherKeys)}"
+                        );
+                        return;
+                    }
+
+                    foreach (var key in thatKeys)
+                    {
+                        CheckJsonNodesEqual(thatDictionary[key], otherDictionary[key], out error);
+                        if (error != null)
+                        {
+                            error.PrependSegment(new Reporting.NameSegment(key));
+                            return;
+                        }
+                    }
+
+                    break;
+                }
+            case Nodes.JsonValue thatValue:
+                {
+                    string thatAsJsonString = thatValue.ToJsonString();
+
+                    // NOTE (mristin):
+                    // This is slow, but there is no way around it at the moment with NET6.
+                    // See:
+                    // * https://github.com/dotnet/runtime/issues/56592
+                    // * https://github.com/dotnet/runtime/issues/55827
+                    // * https://github.com/dotnet/runtime/issues/53406
+                    var otherValue = (other as Nodes.JsonValue)!;
+                    string otherAsJsonString = otherValue.ToJsonString();
+
+                    if (thatAsJsonString != otherAsJsonString)
+                    {
+                        error = new Reporting.Error(
+                            $"Unequal values: {thatAsJsonString} != {otherAsJsonString}"
+                        );
+                        // ReSharper disable once RedundantJumpStatement
+                        return;
+                    }
+
+                    break;
+                }
+            default:
+                throw new System.InvalidOperationException(
+                    $"Unhandled JSON node: {that.GetType()}"
+                );
+        }
+    }
+    }  // public static class CommonJson
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJsonization.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJsonization.cs
new file mode 100644
index 000000000..42fbc331b
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/CommonJsonization.cs
@@ -0,0 +1,158 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Path = System.IO.Path;
+
+namespace dummy.Tests
+{
+    /// <summary>
+    /// Provide methods to load instances from JSON test data.
+    /// </summary>
+    public static class CommonJsonization
+    {
+        public static Our.SomeItem LoadMaximalSomeItem()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "SomeItem",
+                "maximal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.SomeItemFrom(
+                node);
+
+            return instance;
+        }  // public static Our.SomeItem LoadMaximalSomeItem
+
+        public static Our.SomeItem LoadMinimalSomeItem()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "SomeItem",
+                "minimal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.SomeItemFrom(
+                node);
+
+            return instance;
+        }  // public static Our.SomeItem LoadMinimalSomeItem
+
+        public static Our.SpecialItem LoadMaximalSpecialItem()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "SpecialItem",
+                "maximal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.SpecialItemFrom(
+                node);
+
+            return instance;
+        }  // public static Our.SpecialItem LoadMaximalSpecialItem
+
+        public static Our.SpecialItem LoadMinimalSpecialItem()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "SpecialItem",
+                "minimal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.SpecialItemFrom(
+                node);
+
+            return instance;
+        }  // public static Our.SpecialItem LoadMinimalSpecialItem
+
+        public static Our.Container LoadMaximalContainer()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "Container",
+                "maximal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.ContainerFrom(
+                node);
+
+            return instance;
+        }  // public static Our.Container LoadMaximalContainer
+
+        public static Our.Container LoadMinimalContainer()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "Container",
+                "minimal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.ContainerFrom(
+                node);
+
+            return instance;
+        }  // public static Our.Container LoadMinimalContainer
+
+        public static Our.Wrapper LoadMaximalWrapper()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "Wrapper",
+                "maximal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.WrapperFrom(
+                node);
+
+            return instance;
+        }  // public static Our.Wrapper LoadMaximalWrapper
+
+        public static Our.Wrapper LoadMinimalWrapper()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Json",
+                "Expected",
+                "Wrapper",
+                "minimal.json");
+
+            var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+            var instance = Our.Jsonization.Deserialize.WrapperFrom(
+                node);
+
+            return instance;
+        }  // public static Our.Wrapper LoadMinimalWrapper
+    }  // class CommonJsonization
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestCopying.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestCopying.cs
new file mode 100644
index 000000000..a62b0c55c
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestCopying.cs
@@ -0,0 +1,335 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+// We need to use System.MemoryExtension.SequenceEqual.
+using System;  // can't alias
+using System.Collections.Generic;  // can't alias
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestCopying
+    {
+        /// <summary>
+        /// Check that the context is a deep copy of the visited instance.
+        /// </summary>
+        /// <remarks>
+        /// The copy has to equal the original by value, while it must share none
+        /// of the mutable objects with it.
+        /// </remarks>
+        internal class DeepCopyChecker
+            : Our.Visitation.AbstractTransformerWithContext<Our.IClass, bool>
+        {
+            private static bool BytesEqualButDistinct(
+                byte[] that,
+                byte[] other)
+            {
+                // NOTE (mristin):
+                // A byte[] implicitly converts to a ReadOnlySpan, which compares by content.
+                // See: https://stackoverflow.com/a/48599119/1600678
+                return (
+                    !ReferenceEquals(that, other)
+                    && ((System.ReadOnlySpan<byte>)that).SequenceEqual(other));
+            }
+
+            public override bool TransformSomeItem(
+                Our.ISomeItem that,
+                Our.IClass other)
+            {
+                if (!(other is Our.SomeItem casted) || ReferenceEquals(that, other))
+                {
+                    return false;
+                }
+
+                return (
+                    that.Name == casted.Name
+                    && ((that.Nickname != null && casted.Nickname != null)
+                        ? that.Nickname == casted.Nickname
+                        : that.Nickname == null && casted.Nickname == null));
+            }
+
+            public override bool TransformSpecialItem(
+                Our.ISpecialItem that,
+                Our.IClass other)
+            {
+                if (!(other is Our.SpecialItem casted) || ReferenceEquals(that, other))
+                {
+                    return false;
+                }
+
+                return (
+                    that.Name == casted.Name
+                    && ((that.Nickname != null && casted.Nickname != null)
+                        ? that.Nickname == casted.Nickname
+                        : that.Nickname == null && casted.Nickname == null)
+                    && that.Level == casted.Level);
+            }
+
+            public override bool TransformContainer(
+                Our.IContainer that,
+                Our.IClass other)
+            {
+                if (!(other is Our.Container casted) || ReferenceEquals(that, other))
+                {
+                    return false;
+                }
+
+                return (
+                    Check_ListOf_IItem(
+                        that.Items,
+                        casted.Items)
+                    && Check_ListOf_ISomeItem(
+                        that.SomeItems,
+                        casted.SomeItems)
+                    && ((that.SpecialItems != null && casted.SpecialItems != null)
+                        ? Check_ListOf_ISpecialItem(
+                            that.SpecialItems,
+                            casted.SpecialItems)
+                        : that.SpecialItems == null && casted.SpecialItems == null));
+            }
+
+            public override bool TransformWrapper(
+                Our.IWrapper that,
+                Our.IClass other)
+            {
+                if (!(other is Our.Wrapper casted) || ReferenceEquals(that, other))
+                {
+                    return false;
+                }
+
+                return (
+                    Transform(
+                        that.Container,
+                        casted.Container));
+            }
+
+            private bool Check_ListOf_IItem(
+                List<Our.IItem> that,
+                List<Our.IItem> other)
+            {
+                if (ReferenceEquals(that, other) || that.Count != other.Count)
+                {
+                    return false;
+                }
+
+                for (int i = 0; i < that.Count; i++)
+                {
+                    if (!(
+                        Transform(
+                            that[i],
+                            other[i])))
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
+
+            private bool Check_ListOf_ISomeItem(
+                List<Our.ISomeItem> that,
+                List<Our.ISomeItem> other)
+            {
+                if (ReferenceEquals(that, other) || that.Count != other.Count)
+                {
+                    return false;
+                }
+
+                for (int i = 0; i < that.Count; i++)
+                {
+                    if (!(
+                        Transform(
+                            that[i],
+                            other[i])))
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
+
+            private bool Check_ListOf_ISpecialItem(
+                List<Our.ISpecialItem> that,
+                List<Our.ISpecialItem> other)
+            {
+                if (ReferenceEquals(that, other) || that.Count != other.Count)
+                {
+                    return false;
+                }
+
+                for (int i = 0; i < that.Count; i++)
+                {
+                    if (!(
+                        Transform(
+                            that[i],
+                            other[i])))
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
+        }  // internal class DeepCopyChecker
+
+        private static readonly DeepCopyChecker DeepCopyCheckerInstance = (
+            new DeepCopyChecker());
+
+        private static bool SomeItemShallowEquals(
+            Our.SomeItem that,
+            Our.SomeItem other)
+        {
+            return that.Name == other.Name && that.Nickname == other.Nickname;
+        }
+
+        private static bool SpecialItemShallowEquals(
+            Our.SpecialItem that,
+            Our.SpecialItem other)
+        {
+            return (
+                that.Name == other.Name
+                && that.Nickname == other.Nickname
+                && that.Level == other.Level);
+        }
+
+        private static bool ContainerShallowEquals(
+            Our.Container that,
+            Our.Container other)
+        {
+            return (
+                that.Items == other.Items
+                && that.SomeItems == other.SomeItems
+                && that.SpecialItems == other.SpecialItems);
+        }
+
+        private static bool WrapperShallowEquals(
+            Our.Wrapper that,
+            Our.Wrapper other)
+        {
+            return that.Container == other.Container;
+        }
+
+        [Test]
+        public void Test_SomeItem_shallow_copy()
+        {
+            Our.SomeItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem());
+
+            var instanceCopy = Our.Copying.Shallow(instance);
+
+            Assert.IsTrue(
+                SomeItemShallowEquals(
+                    instance, instanceCopy),
+                "SomeItem");
+        }  // public void Test_SomeItem_shallow_copy
+
+        [Test]
+        public void Test_SomeItem_deep_copy()
+        {
+            Our.SomeItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem());
+
+            var instanceCopy = Our.Copying.Deep(instance);
+
+            Assert.IsTrue(
+                DeepCopyCheckerInstance.Transform(
+                    instance, instanceCopy),
+                "SomeItem");
+        }  // public void Test_SomeItem_deep_copy
+
+        [Test]
+        public void Test_SpecialItem_shallow_copy()
+        {
+            Our.SpecialItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem());
+
+            var instanceCopy = Our.Copying.Shallow(instance);
+
+            Assert.IsTrue(
+                SpecialItemShallowEquals(
+                    instance, instanceCopy),
+                "SpecialItem");
+        }  // public void Test_SpecialItem_shallow_copy
+
+        [Test]
+        public void Test_SpecialItem_deep_copy()
+        {
+            Our.SpecialItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem());
+
+            var instanceCopy = Our.Copying.Deep(instance);
+
+            Assert.IsTrue(
+                DeepCopyCheckerInstance.Transform(
+                    instance, instanceCopy),
+                "SpecialItem");
+        }  // public void Test_SpecialItem_deep_copy
+
+        [Test]
+        public void Test_Container_shallow_copy()
+        {
+            Our.Container instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer());
+
+            var instanceCopy = Our.Copying.Shallow(instance);
+
+            Assert.IsTrue(
+                ContainerShallowEquals(
+                    instance, instanceCopy),
+                "Container");
+        }  // public void Test_Container_shallow_copy
+
+        [Test]
+        public void Test_Container_deep_copy()
+        {
+            Our.Container instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer());
+
+            var instanceCopy = Our.Copying.Deep(instance);
+
+            Assert.IsTrue(
+                DeepCopyCheckerInstance.Transform(
+                    instance, instanceCopy),
+                "Container");
+        }  // public void Test_Container_deep_copy
+
+        [Test]
+        public void Test_Wrapper_shallow_copy()
+        {
+            Our.Wrapper instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper());
+
+            var instanceCopy = Our.Copying.Shallow(instance);
+
+            Assert.IsTrue(
+                WrapperShallowEquals(
+                    instance, instanceCopy),
+                "Wrapper");
+        }  // public void Test_Wrapper_shallow_copy
+
+        [Test]
+        public void Test_Wrapper_deep_copy()
+        {
+            Our.Wrapper instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper());
+
+            var instanceCopy = Our.Copying.Deep(instance);
+
+            Assert.IsTrue(
+                DeepCopyCheckerInstance.Transform(
+                    instance, instanceCopy),
+                "Wrapper");
+        }  // public void Test_Wrapper_deep_copy
+    }  // class TestCopying
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendAndVisitorThrough.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendAndVisitorThrough.cs
new file mode 100644
index 000000000..60d25a7b4
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendAndVisitorThrough.cs
@@ -0,0 +1,201 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Directory = System.IO.Directory;
+using Path = System.IO.Path;
+
+using NUnit.Framework; // can't alias
+using System.Collections.Generic;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestDescendAndVisitorThrough
+    {
+        class TracingVisitorThrough : Our.Visitation.VisitorThrough
+        {
+            public readonly List<string> Log = new List<string>();
+
+            public override void Visit(IClass that)
+            {
+                Log.Add(Our.Tests.Common.Trace(that));
+                base.Visit(that);
+            }
+        }
+
+        private static void AssertDescendAndVisitorThroughSame(
+            Our.IClass instance)
+        {
+            var logFromDescend = new List<string>();
+            foreach (var subInstance in instance.Descend())
+            {
+                logFromDescend.Add(Our.Tests.Common.Trace(subInstance));
+            }
+
+            var visitor = new TracingVisitorThrough();
+            visitor.Visit(instance);
+            var traceFromVisitor = visitor.Log;
+
+            Assert.IsNotEmpty(traceFromVisitor);
+
+            Assert.AreEqual(
+                Our.Tests.Common.Trace(instance),
+                traceFromVisitor[0]);
+
+            traceFromVisitor.RemoveAt(0);
+
+            Assert.That(traceFromVisitor, Is.EquivalentTo(logFromDescend));
+        }
+
+        private static void CompareOrRerecordTrace(
+            IClass instance,
+            string expectedPath)
+        {
+            var writer = new System.IO.StringWriter();
+            foreach (var descendant in instance.Descend())
+            {
+                writer.WriteLine(Our.Tests.Common.Trace(descendant));
+            }
+
+            string got = writer.ToString();
+
+            if (Our.Tests.Common.RecordMode)
+            {
+                string? parent = Path.GetDirectoryName(expectedPath);
+                if (parent != null)
+                {
+                    if (!Directory.Exists(parent))
+                    {
+                        Directory.CreateDirectory(parent);
+                    }
+                }
+
+                System.IO.File.WriteAllText(expectedPath, got);
+            }
+            else
+            {
+                if (!System.IO.File.Exists(expectedPath))
+                {
+                    throw new System.IO.FileNotFoundException(
+                        "The file with the recorded trace does not " +
+                        $"exist: {expectedPath}; maybe you want to set the environment " +
+                        $"variable {Our.Tests.Common.RecordModeEnvironmentVariableName}?");
+                }
+
+                string expected = System.IO.File.ReadAllText(expectedPath);
+                Assert.AreEqual(
+                    expected.Replace("\r\n", "\n"),
+                    got.Replace("\r\n", "\n"),
+                    $"The expected trace from {expectedPath} does not match the actual one");
+            }
+        }
+
+        [Test]
+        public void Test_Descend_of_SomeItem()
+        {
+            Our.SomeItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Descend",
+                    "SomeItem",
+                    "maximal.json.trace"));
+        }  // public void Test_Descend_of_SomeItem
+
+        [Test]
+        public void Test_Descend_against_VisitorThrough_for_SomeItem()
+        {
+            Our.SomeItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem());
+
+            AssertDescendAndVisitorThroughSame(
+                instance);
+        }  // public void Test_Descend_against_VisitorThrough_for_SomeItem
+
+        [Test]
+        public void Test_Descend_of_SpecialItem()
+        {
+            Our.SpecialItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Descend",
+                    "SpecialItem",
+                    "maximal.json.trace"));
+        }  // public void Test_Descend_of_SpecialItem
+
+        [Test]
+        public void Test_Descend_against_VisitorThrough_for_SpecialItem()
+        {
+            Our.SpecialItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem());
+
+            AssertDescendAndVisitorThroughSame(
+                instance);
+        }  // public void Test_Descend_against_VisitorThrough_for_SpecialItem
+
+        [Test]
+        public void Test_Descend_of_Container()
+        {
+            Our.Container instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Descend",
+                    "Container",
+                    "maximal.json.trace"));
+        }  // public void Test_Descend_of_Container
+
+        [Test]
+        public void Test_Descend_against_VisitorThrough_for_Container()
+        {
+            Our.Container instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer());
+
+            AssertDescendAndVisitorThroughSame(
+                instance);
+        }  // public void Test_Descend_against_VisitorThrough_for_Container
+
+        [Test]
+        public void Test_Descend_of_Wrapper()
+        {
+            Our.Wrapper instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Descend",
+                    "Wrapper",
+                    "maximal.json.trace"));
+        }  // public void Test_Descend_of_Wrapper
+
+        [Test]
+        public void Test_Descend_against_VisitorThrough_for_Wrapper()
+        {
+            Our.Wrapper instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper());
+
+            AssertDescendAndVisitorThroughSame(
+                instance);
+        }  // public void Test_Descend_against_VisitorThrough_for_Wrapper
+    }  // class TestDescendAndVisitorThrough
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendOnce.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendOnce.cs
new file mode 100644
index 000000000..18516ee68
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestDescendOnce.cs
@@ -0,0 +1,125 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Directory = System.IO.Directory;
+using Path = System.IO.Path;
+
+using NUnit.Framework; // can't alias
+
+namespace dummy.Tests
+{
+    public class TestDescendOnce
+    {
+        private static void CompareOrRerecordTrace(
+            IClass instance,
+            string expectedPath)
+        {
+            var writer = new System.IO.StringWriter();
+            foreach (var descendant in instance.DescendOnce())
+            {
+                writer.WriteLine(Our.Tests.Common.Trace(descendant));
+            }
+
+            string got = writer.ToString();
+
+            if (Our.Tests.Common.RecordMode)
+            {
+                string? parent = Path.GetDirectoryName(expectedPath);
+                if (parent != null)
+                {
+                    if (!Directory.Exists(parent))
+                    {
+                        Directory.CreateDirectory(parent);
+                    }
+                }
+
+                System.IO.File.WriteAllText(expectedPath, got);
+            }
+            else
+            {
+                if (!System.IO.File.Exists(expectedPath))
+                {
+                    throw new System.IO.FileNotFoundException(
+                        $"The file with the recorded trace does not exist: {expectedPath}; " +
+                        "maybe you want to set the environment " +
+                        $"variable {Our.Tests.Common.RecordModeEnvironmentVariableName}?");
+                }
+
+                string expected = System.IO.File.ReadAllText(expectedPath);
+                Assert.AreEqual(
+                    expected.Replace("\r\n", "\n"),
+                    got.Replace("\r\n", "\n"),
+                    $"The expected trace from {expectedPath} does not match the actual one");
+            }
+        }
+
+        [Test]
+        public void Test_SomeItem()
+        {
+            Our.SomeItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "DescendOnce",
+                    "SomeItem",
+                    "maximal.json.trace"));
+        }  // public void Test_SomeItem
+
+        [Test]
+        public void Test_SpecialItem()
+        {
+            Our.SpecialItem instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "DescendOnce",
+                    "SpecialItem",
+                    "maximal.json.trace"));
+        }  // public void Test_SpecialItem
+
+        [Test]
+        public void Test_Container()
+        {
+            Our.Container instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "DescendOnce",
+                    "Container",
+                    "maximal.json.trace"));
+        }  // public void Test_Container
+
+        [Test]
+        public void Test_Wrapper()
+        {
+            Our.Wrapper instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper());
+
+            CompareOrRerecordTrace(
+                instance,
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "DescendOnce",
+                    "Wrapper",
+                    "maximal.json.trace"));
+        }  // public void Test_Wrapper
+    }  // class TestDescendOnce
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestEnhancing.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestEnhancing.cs
new file mode 100644
index 000000000..e1cea4910
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestEnhancing.cs
@@ -0,0 +1,168 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy; // renamed
+using OurEnhancing = dummy.Enhancing; // renamed
+
+using System.Collections.Generic; // can't alias
+using System.Linq; // can't alias
+
+using NUnit.Framework; // can't alias
+
+namespace dummy.Tests
+{
+    public class TestEnhancing
+    {
+        class Enhancement
+        {
+            public readonly long SomeCustomId;
+
+            public Enhancement(long someCustomId)
+            {
+                SomeCustomId = someCustomId;
+            }
+        }
+
+        private static OurEnhancing.Enhancer<Enhancement> CreateEnhancer()
+        {
+            long lastCustomId = 0;
+
+            var enhancementFactory = new System.Func<IClass, Enhancement>(
+                delegate
+                {
+                    lastCustomId++;
+                    return new Enhancement(lastCustomId);
+                }
+            );
+
+            return new OurEnhancing.Enhancer<Enhancement>(enhancementFactory);
+        }
+
+        [Test]
+        public void Test_SomeItem()
+        {
+            var instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSomeItem()
+            );
+
+            var enhancer = CreateEnhancer();
+
+            Assert.IsNull(enhancer.Unwrap(instance));
+
+            var wrapped = enhancer.Wrap(instance);
+            Assert.IsNotNull(wrapped);
+
+            var idSet = new HashSet<long>();
+
+            idSet.Add(enhancer.MustUnwrap(wrapped).SomeCustomId);
+            idSet.UnionWith(
+                wrapped
+                    .Descend()
+                    .Select(
+                        (descendant) =>
+                            enhancer.MustUnwrap(descendant).SomeCustomId
+                        )
+            );
+
+            Assert.AreEqual(1, idSet.Min());
+            Assert.AreEqual(idSet.Count, idSet.Max());
+        }  // public void Test_SomeItem
+
+        [Test]
+        public void Test_SpecialItem()
+        {
+            var instance = (
+                Our.Tests.CommonJsonization.LoadMaximalSpecialItem()
+            );
+
+            var enhancer = CreateEnhancer();
+
+            Assert.IsNull(enhancer.Unwrap(instance));
+
+            var wrapped = enhancer.Wrap(instance);
+            Assert.IsNotNull(wrapped);
+
+            var idSet = new HashSet<long>();
+
+            idSet.Add(enhancer.MustUnwrap(wrapped).SomeCustomId);
+            idSet.UnionWith(
+                wrapped
+                    .Descend()
+                    .Select(
+                        (descendant) =>
+                            enhancer.MustUnwrap(descendant).SomeCustomId
+                        )
+            );
+
+            Assert.AreEqual(1, idSet.Min());
+            Assert.AreEqual(idSet.Count, idSet.Max());
+        }  // public void Test_SpecialItem
+
+        [Test]
+        public void Test_Container()
+        {
+            var instance = (
+                Our.Tests.CommonJsonization.LoadMaximalContainer()
+            );
+
+            var enhancer = CreateEnhancer();
+
+            Assert.IsNull(enhancer.Unwrap(instance));
+
+            var wrapped = enhancer.Wrap(instance);
+            Assert.IsNotNull(wrapped);
+
+            var idSet = new HashSet<long>();
+
+            idSet.Add(enhancer.MustUnwrap(wrapped).SomeCustomId);
+            idSet.UnionWith(
+                wrapped
+                    .Descend()
+                    .Select(
+                        (descendant) =>
+                            enhancer.MustUnwrap(descendant).SomeCustomId
+                        )
+            );
+
+            Assert.AreEqual(1, idSet.Min());
+            Assert.AreEqual(idSet.Count, idSet.Max());
+        }  // public void Test_Container
+
+        [Test]
+        public void Test_Wrapper()
+        {
+            var instance = (
+                Our.Tests.CommonJsonization.LoadMaximalWrapper()
+            );
+
+            var enhancer = CreateEnhancer();
+
+            Assert.IsNull(enhancer.Unwrap(instance));
+
+            var wrapped = enhancer.Wrap(instance);
+            Assert.IsNotNull(wrapped);
+
+            var idSet = new HashSet<long>();
+
+            idSet.Add(enhancer.MustUnwrap(wrapped).SomeCustomId);
+            idSet.UnionWith(
+                wrapped
+                    .Descend()
+                    .Select(
+                        (descendant) =>
+                            enhancer.MustUnwrap(descendant).SomeCustomId
+                        )
+            );
+
+            Assert.AreEqual(1, idSet.Min());
+            Assert.AreEqual(idSet.Count, idSet.Max());
+        }  // public void Test_Wrapper
+    }  // class TestEnhancing
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfConcreteClasses.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfConcreteClasses.cs
new file mode 100644
index 000000000..bb17a7bfe
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfConcreteClasses.cs
@@ -0,0 +1,798 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Directory = System.IO.Directory;
+using Nodes = System.Text.Json.Nodes;
+using Path = System.IO.Path;
+
+using System.Collections.Generic;  // can't alias
+using System.Linq;  // can't alias
+using NUnit.Framework; // can't alias
+
+namespace dummy.Tests
+{
+    public class TestJsonizationOfConcreteClasses
+    {
+        private static void AssertSerializeDeserializeEqualsOriginal(
+            Nodes.JsonNode originalNode, Our.IClass instance, string path)
+        {
+            Nodes.JsonObject? serialized = null;
+            try
+            {
+                serialized = Our.Jsonization.Serialize.ToJsonObject(instance);
+            }
+            catch (System.Exception exception)
+            {
+                Assert.Fail(
+                    "Expected no exception upon serialization of an instance " +
+                    $"de-serialized from {path}, but got: {exception}"
+                );
+            }
+
+            if (serialized == null)
+            {
+                Assert.Fail(
+                    $"Unexpected null serialization of an instance from {path}"
+                );
+            }
+            else
+            {
+                Our.Tests.CommonJson.CheckJsonNodesEqual(
+                    originalNode,
+                    serialized,
+                    out Reporting.Error? inequalityError);
+                if (inequalityError != null)
+                {
+                    Assert.Fail(
+                        $"The original JSON from {path} is unequal the serialized JSON: " +
+                        $"{Reporting.GenerateJsonPath(inequalityError.PathSegments)}: " +
+                        inequalityError.Cause
+                    );
+                }
+            }
+        }
+
+        private static void AssertEqualsExpectedOrRerecordDeserializationException(
+            Our.Jsonization.Exception? exception,
+            string path)
+        {
+            if (exception == null)
+            {
+                Assert.Fail(
+                    $"Expected a Jsonization exception when de-serializing {path}, but got none."
+                );
+            }
+            else
+            {
+                string exceptionPath = path + ".exception";
+                string got = exception.Message;
+                if (Our.Tests.Common.RecordMode)
+                {
+                    System.IO.File.WriteAllText(exceptionPath, got);
+                }
+                else
+                {
+                    if (!System.IO.File.Exists(exceptionPath))
+                    {
+                        throw new System.IO.FileNotFoundException(
+                            $"The file with the recorded exception does not exist: {exceptionPath}; " +
+                            "maybe you want to set the environment " +
+                            $"variable {Our.Tests.Common.RecordModeEnvironmentVariableName}?");
+                    }
+
+                    string expected = System.IO.File.ReadAllText(exceptionPath);
+                    Assert.AreEqual(
+                        expected.Replace("\r\n", "\n"),
+                        got.Replace("\r\n", "\n"),
+                        $"The expected exception does not match the actual one for the file {path}");
+                }
+            }
+        }
+
+        [Test]
+        public void Test_SomeItem_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Json",
+                    "Expected",
+                    "SomeItem"
+                ),
+                "*.json",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                var instance = Our.Jsonization.Deserialize.SomeItemFrom(
+                    node);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    node, instance, path);
+            }
+        }  // public void Test_SomeItem_ok
+
+        [Test]
+        public void Test_SomeItem_deserialization_from_non_object_fail()
+        {
+            var node = Nodes.JsonValue.Create("INVALID")
+                ?? throw new System.InvalidOperationException(
+                    "Unexpected failure of the node creation");
+
+            Our.Jsonization.Exception? exception = null;
+            try
+            {
+                var _ = Our.Jsonization.Deserialize.SomeItemFrom(
+                    node);
+            }
+            catch (Our.Jsonization.Exception observedException)
+            {
+                exception = observedException;
+            }
+
+            if (exception == null)
+            {
+                throw new AssertionException("Expected an exception, but got none");
+            }
+
+            if (
+                !exception.Message.StartsWith(
+                    "Expected a JsonObject representing SomeItem, but got "))
+            {
+                throw new AssertionException(
+                    $"Unexpected exception message: {exception.Message}");
+            }
+        }  // public void Test_SomeItem_deserialization_from_non_object_fail
+
+        [Test]
+        public void Test_SomeItem_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "SomeItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SomeItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    Our.Jsonization.Exception? exception = null;
+                    try
+                    {
+                        var _ = Our.Jsonization.Deserialize.SomeItemFrom(
+                            node);
+                    }
+                    catch (Our.Jsonization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_SomeItem_deserialization_fail
+
+        [Test]
+        public void Test_SomeItem_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "SomeItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SomeItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    var instance = Our.Jsonization.Deserialize.SomeItemFrom(
+                        node);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_SomeItem_verification_fail
+
+        [Test]
+        public void Test_SpecialItem_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Json",
+                    "Expected",
+                    "SpecialItem"
+                ),
+                "*.json",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                var instance = Our.Jsonization.Deserialize.SpecialItemFrom(
+                    node);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    node, instance, path);
+            }
+        }  // public void Test_SpecialItem_ok
+
+        [Test]
+        public void Test_SpecialItem_deserialization_from_non_object_fail()
+        {
+            var node = Nodes.JsonValue.Create("INVALID")
+                ?? throw new System.InvalidOperationException(
+                    "Unexpected failure of the node creation");
+
+            Our.Jsonization.Exception? exception = null;
+            try
+            {
+                var _ = Our.Jsonization.Deserialize.SpecialItemFrom(
+                    node);
+            }
+            catch (Our.Jsonization.Exception observedException)
+            {
+                exception = observedException;
+            }
+
+            if (exception == null)
+            {
+                throw new AssertionException("Expected an exception, but got none");
+            }
+
+            if (
+                !exception.Message.StartsWith(
+                    "Expected a JsonObject representing SpecialItem, but got "))
+            {
+                throw new AssertionException(
+                    $"Unexpected exception message: {exception.Message}");
+            }
+        }  // public void Test_SpecialItem_deserialization_from_non_object_fail
+
+        [Test]
+        public void Test_SpecialItem_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "SpecialItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SpecialItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    Our.Jsonization.Exception? exception = null;
+                    try
+                    {
+                        var _ = Our.Jsonization.Deserialize.SpecialItemFrom(
+                            node);
+                    }
+                    catch (Our.Jsonization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_SpecialItem_deserialization_fail
+
+        [Test]
+        public void Test_SpecialItem_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "SpecialItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SpecialItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    var instance = Our.Jsonization.Deserialize.SpecialItemFrom(
+                        node);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_SpecialItem_verification_fail
+
+        [Test]
+        public void Test_Container_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Json",
+                    "Expected",
+                    "Container"
+                ),
+                "*.json",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                var instance = Our.Jsonization.Deserialize.ContainerFrom(
+                    node);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    node, instance, path);
+            }
+        }  // public void Test_Container_ok
+
+        [Test]
+        public void Test_Container_deserialization_from_non_object_fail()
+        {
+            var node = Nodes.JsonValue.Create("INVALID")
+                ?? throw new System.InvalidOperationException(
+                    "Unexpected failure of the node creation");
+
+            Our.Jsonization.Exception? exception = null;
+            try
+            {
+                var _ = Our.Jsonization.Deserialize.ContainerFrom(
+                    node);
+            }
+            catch (Our.Jsonization.Exception observedException)
+            {
+                exception = observedException;
+            }
+
+            if (exception == null)
+            {
+                throw new AssertionException("Expected an exception, but got none");
+            }
+
+            if (
+                !exception.Message.StartsWith(
+                    "Expected a JsonObject representing Container, but got "))
+            {
+                throw new AssertionException(
+                    $"Unexpected exception message: {exception.Message}");
+            }
+        }  // public void Test_Container_deserialization_from_non_object_fail
+
+        [Test]
+        public void Test_Container_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "Container"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Container for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    Our.Jsonization.Exception? exception = null;
+                    try
+                    {
+                        var _ = Our.Jsonization.Deserialize.ContainerFrom(
+                            node);
+                    }
+                    catch (Our.Jsonization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_Container_deserialization_fail
+
+        [Test]
+        public void Test_Container_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "Container"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Container for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    var instance = Our.Jsonization.Deserialize.ContainerFrom(
+                        node);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_Container_verification_fail
+
+        [Test]
+        public void Test_Wrapper_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Json",
+                    "Expected",
+                    "Wrapper"
+                ),
+                "*.json",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                var instance = Our.Jsonization.Deserialize.WrapperFrom(
+                    node);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    node, instance, path);
+            }
+        }  // public void Test_Wrapper_ok
+
+        [Test]
+        public void Test_Wrapper_deserialization_from_non_object_fail()
+        {
+            var node = Nodes.JsonValue.Create("INVALID")
+                ?? throw new System.InvalidOperationException(
+                    "Unexpected failure of the node creation");
+
+            Our.Jsonization.Exception? exception = null;
+            try
+            {
+                var _ = Our.Jsonization.Deserialize.WrapperFrom(
+                    node);
+            }
+            catch (Our.Jsonization.Exception observedException)
+            {
+                exception = observedException;
+            }
+
+            if (exception == null)
+            {
+                throw new AssertionException("Expected an exception, but got none");
+            }
+
+            if (
+                !exception.Message.StartsWith(
+                    "Expected a JsonObject representing Wrapper, but got "))
+            {
+                throw new AssertionException(
+                    $"Unexpected exception message: {exception.Message}");
+            }
+        }  // public void Test_Wrapper_deserialization_from_non_object_fail
+
+        [Test]
+        public void Test_Wrapper_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "Wrapper"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Wrapper for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    Our.Jsonization.Exception? exception = null;
+                    try
+                    {
+                        var _ = Our.Jsonization.Deserialize.WrapperFrom(
+                            node);
+                    }
+                    catch (Our.Jsonization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_Wrapper_deserialization_fail
+
+        [Test]
+        public void Test_Wrapper_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Json",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "Wrapper"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Wrapper for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.json",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    var node = Our.Tests.CommonJson.ReadFromFile(path);
+
+                    var instance = Our.Jsonization.Deserialize.WrapperFrom(
+                        node);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_Wrapper_verification_fail
+
+        /// <summary>
+        /// Read the first recorded example of the <paramref name="modelType" />.
+        /// </summary>
+        private static Nodes.JsonNode LoadTheFirstExpected(string modelType)
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Json",
+                    "Expected",
+                    modelType),
+                "*.json",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            Assert.IsNotEmpty(
+                paths,
+                $"Expected at least one recorded example of {modelType}, but got none");
+
+            return Our.Tests.CommonJson.ReadFromFile(paths[0]);
+        }
+
+        [Test]
+        public void TestSpecialItemLevelSerializationOutOfRange()
+        {
+            foreach (var value in new long[] { 9007199254740992L, -9007199254740992L })
+            {
+                var node = LoadTheFirstExpected(
+                    "SpecialItem");
+
+                var instance = Our.Jsonization.Deserialize.SpecialItemFrom(
+                    node);
+
+                instance.Level = value;
+
+                Our.Jsonization.SerializationException? exception = null;
+                try
+                {
+                    var _ = Our.Jsonization.Serialize.ToJsonObject(instance);
+                }
+                catch (Our.Jsonization.SerializationException observedException)
+                {
+                    exception = observedException;
+                }
+
+                Assert.IsNotNull(
+                    exception,
+                    "Expected the serialization to fail at " +
+                        "Level" +
+                        ", but it succeeded");
+
+                Assert.AreEqual(
+                    "Level",
+                    exception!.Path);
+            }
+        }  // public void TestSpecialItemLevelSerializationOutOfRange
+    }  // class TestJsonizationOfConcreteClasses
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfEnums.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfEnums.cs
new file mode 100644
index 000000000..cd84ef87a
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfEnums.cs
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Nodes = System.Text.Json.Nodes;
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestJsonizationOfEnums
+    {
+        
+    }  // class TestJsonizationOfEnums
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfInterfaces.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfInterfaces.cs
new file mode 100644
index 000000000..59ac7f0c3
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestJsonizationOfInterfaces.cs
@@ -0,0 +1,135 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestJsonizationOfInterfaces
+    {
+        [Test]
+        public void Test_round_trip_IItem_from_SomeItem()
+        {
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSomeItem();
+
+            var jsonObject = Our.Jsonization.Serialize.ToJsonObject(instance);
+
+            var anotherInstance = Our.Jsonization.Deserialize.IItemFrom(
+                jsonObject);
+
+            var anotherJsonObject = Our.Jsonization.Serialize.ToJsonObject(
+                anotherInstance);
+
+            Our.Tests.CommonJson.CheckJsonNodesEqual(
+                jsonObject,
+                anotherJsonObject,
+                out Our.Reporting.Error? error);
+
+            if (error != null)
+            {
+                Assert.Fail(
+                    "When we serialize the complete instance of SomeItem " +
+                    "as IItem, we get an error in the round trip: " +
+                    $"{Reporting.GenerateJsonPath(error.PathSegments)}: " +
+                    error.Cause
+                );
+            }
+        }  // void Test_round_trip_IItem_from_SomeItem
+
+        [Test]
+        public void Test_round_trip_IItem_from_SpecialItem()
+        {
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSpecialItem();
+
+            var jsonObject = Our.Jsonization.Serialize.ToJsonObject(instance);
+
+            var anotherInstance = Our.Jsonization.Deserialize.IItemFrom(
+                jsonObject);
+
+            var anotherJsonObject = Our.Jsonization.Serialize.ToJsonObject(
+                anotherInstance);
+
+            Our.Tests.CommonJson.CheckJsonNodesEqual(
+                jsonObject,
+                anotherJsonObject,
+                out Our.Reporting.Error? error);
+
+            if (error != null)
+            {
+                Assert.Fail(
+                    "When we serialize the complete instance of SpecialItem " +
+                    "as IItem, we get an error in the round trip: " +
+                    $"{Reporting.GenerateJsonPath(error.PathSegments)}: " +
+                    error.Cause
+                );
+            }
+        }  // void Test_round_trip_IItem_from_SpecialItem
+
+        [Test]
+        public void Test_round_trip_ISomeItem_from_SpecialItem()
+        {
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSpecialItem();
+
+            var jsonObject = Our.Jsonization.Serialize.ToJsonObject(instance);
+
+            var anotherInstance = Our.Jsonization.Deserialize.ISomeItemFrom(
+                jsonObject);
+
+            var anotherJsonObject = Our.Jsonization.Serialize.ToJsonObject(
+                anotherInstance);
+
+            Our.Tests.CommonJson.CheckJsonNodesEqual(
+                jsonObject,
+                anotherJsonObject,
+                out Our.Reporting.Error? error);
+
+            if (error != null)
+            {
+                Assert.Fail(
+                    "When we serialize the complete instance of SpecialItem " +
+                    "as ISomeItem, we get an error in the round trip: " +
+                    $"{Reporting.GenerateJsonPath(error.PathSegments)}: " +
+                    error.Cause
+                );
+            }
+        }  // void Test_round_trip_ISomeItem_from_SpecialItem
+
+        [Test]
+        public void Test_round_trip_ISomeItem_from_SomeItem()
+        {
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSomeItem();
+
+            var jsonObject = Our.Jsonization.Serialize.ToJsonObject(instance);
+
+            var anotherInstance = Our.Jsonization.Deserialize.ISomeItemFrom(
+                jsonObject);
+
+            var anotherJsonObject = Our.Jsonization.Serialize.ToJsonObject(
+                anotherInstance);
+
+            Our.Tests.CommonJson.CheckJsonNodesEqual(
+                jsonObject,
+                anotherJsonObject,
+                out Our.Reporting.Error? error);
+
+            if (error != null)
+            {
+                Assert.Fail(
+                    "When we serialize the complete instance of SomeItem " +
+                    "as ISomeItem, we get an error in the round trip: " +
+                    $"{Reporting.GenerateJsonPath(error.PathSegments)}: " +
+                    error.Cause
+                );
+            }
+        }  // void Test_round_trip_ISomeItem_from_SomeItem
+    }  // class TestJsonizationOfInterfaces
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestOverXOrEmpty.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestOverXOrEmpty.cs
new file mode 100644
index 000000000..f3a9ee376
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestOverXOrEmpty.cs
@@ -0,0 +1,40 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestOverXOrEmpty
+    {
+        [Test]
+        public void Test_Container_OverSpecialItemsOrEmpty()
+        {
+            foreach (Our.Container instance in new[]
+            {
+                Our.Tests.CommonJsonization.LoadMinimalContainer(),
+                Our.Tests.CommonJsonization.LoadMaximalContainer()
+            })
+            {
+                int count = 0;
+                foreach (var _ in instance.OverSpecialItemsOrEmpty())
+                {
+                    count++;
+                }
+
+                Assert.AreEqual(
+                    instance.SpecialItems?.Count ?? 0,
+                    count);
+            }
+        }  // public void Test_Container_OverSpecialItemsOrEmpty
+    }  // class TestOverXOrEmpty
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestStringHelpers.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestStringHelpers.cs
new file mode 100644
index 000000000..45205caac
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestStringHelpers.cs
@@ -0,0 +1,411 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    /// <summary>
+    /// Test <c>len</c>, the slicing of strings and <c>find</c> as used in
+    /// the transpiled code.
+    /// </summary>
+    /// <remarks>
+    /// The transpiled code follows the Python implementation, since Python is
+    /// the language of the meta-model specifications. Hence, the lengths and
+    /// the positions count the characters (code points). The expected values have
+    /// been computed with Python, and all the SDKs test against the very same
+    /// cases.
+    /// </remarks>
+    public class TestStringHelpers
+    {
+        [Test, Description("len('') gives 0: empty text")]
+        public void Test_len_empty_text()
+        {
+            Assert.AreEqual(
+                0,
+                Our.Common.StringHelpers.Len(
+                    ""));
+        }  // void Test_len_empty_text
+
+        [Test, Description("len('abc') gives 3: ASCII text")]
+        public void Test_len_ASCII_text()
+        {
+            Assert.AreEqual(
+                3,
+                Our.Common.StringHelpers.Len(
+                    "abc"));
+        }  // void Test_len_ASCII_text
+
+        [Test, Description("len('é-') gives 2: character of two UTF-8 bytes")]
+        public void Test_len_character_of_two_UTF_8_bytes()
+        {
+            Assert.AreEqual(
+                2,
+                Our.Common.StringHelpers.Len(
+                    "é-"));
+        }  // void Test_len_character_of_two_UTF_8_bytes
+
+        [Test, Description("len('😀-') gives 2: character beyond the Basic Multilingual Plane")]
+        public void Test_len_character_beyond_the_Basic_Multilingual_Plane()
+        {
+            Assert.AreEqual(
+                2,
+                Our.Common.StringHelpers.Len(
+                    "😀-"));
+        }  // void Test_len_character_beyond_the_Basic_Multilingual_Plane
+
+        [Test, Description("len('aé😀b😀') gives 5: mixed characters")]
+        public void Test_len_mixed_characters()
+        {
+            Assert.AreEqual(
+                5,
+                Our.Common.StringHelpers.Len(
+                    "aé😀b😀"));
+        }  // void Test_len_mixed_characters
+
+        [Test, Description("'abcde'[1:3] gives 'bc': start and end")]
+        public void Test_slice_start_and_end()
+        {
+            Assert.AreEqual(
+                "bc",
+                Our.Common.StringHelpers.Slice("abcde", 1, 3));
+        }  // void Test_slice_start_and_end
+
+        [Test, Description("'abcde'[:2] gives 'ab': no start")]
+        public void Test_slice_no_start()
+        {
+            Assert.AreEqual(
+                "ab",
+                Our.Common.StringHelpers.Slice("abcde", 0, 2));
+        }  // void Test_slice_no_start
+
+        [Test, Description("'abcde'[3:] gives 'de': no end")]
+        public void Test_slice_no_end()
+        {
+            Assert.AreEqual(
+                "de",
+                Our.Common.StringHelpers.Slice("abcde", 3));
+        }  // void Test_slice_no_end
+
+        [Test, Description("'abcde'[:] gives 'abcde': neither start nor end")]
+        public void Test_slice_neither_start_nor_end()
+        {
+            Assert.AreEqual(
+                "abcde",
+                Our.Common.StringHelpers.Slice("abcde", 0));
+        }  // void Test_slice_neither_start_nor_end
+
+        [Test, Description("'abcde'[-2:] gives 'de': negative start counts from the end")]
+        public void Test_slice_negative_start_counts_from_the_end()
+        {
+            Assert.AreEqual(
+                "de",
+                Our.Common.StringHelpers.Slice("abcde", -2));
+        }  // void Test_slice_negative_start_counts_from_the_end
+
+        [Test, Description("'abcde'[:-2] gives 'abc': negative end counts from the end")]
+        public void Test_slice_negative_end_counts_from_the_end()
+        {
+            Assert.AreEqual(
+                "abc",
+                Our.Common.StringHelpers.Slice("abcde", 0, -2));
+        }  // void Test_slice_negative_end_counts_from_the_end
+
+        [Test, Description("'abcde'[-4:-1] gives 'bcd': negative start and end")]
+        public void Test_slice_negative_start_and_end()
+        {
+            Assert.AreEqual(
+                "bcd",
+                Our.Common.StringHelpers.Slice("abcde", -4, -1));
+        }  // void Test_slice_negative_start_and_end
+
+        [Test, Description("'abcde'[-10:2] gives 'ab': negative start before the beginning is clamped")]
+        public void Test_slice_negative_start_before_the_beginning_is_clamped()
+        {
+            Assert.AreEqual(
+                "ab",
+                Our.Common.StringHelpers.Slice("abcde", -10, 2));
+        }  // void Test_slice_negative_start_before_the_beginning_is_clamped
+
+        [Test, Description("'abcde'[2:10] gives 'cde': end beyond the end is clamped")]
+        public void Test_slice_end_beyond_the_end_is_clamped()
+        {
+            Assert.AreEqual(
+                "cde",
+                Our.Common.StringHelpers.Slice("abcde", 2, 10));
+        }  // void Test_slice_end_beyond_the_end_is_clamped
+
+        [Test, Description("'abcde'[10:] gives '': start beyond the end gives empty")]
+        public void Test_slice_start_beyond_the_end_gives_empty()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("abcde", 10));
+        }  // void Test_slice_start_beyond_the_end_gives_empty
+
+        [Test, Description("'abcde'[3:1] gives '': start after end gives empty")]
+        public void Test_slice_start_after_end_gives_empty()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("abcde", 3, 1));
+        }  // void Test_slice_start_after_end_gives_empty
+
+        [Test, Description("'abcde'[-1:-3] gives '': negative start after negative end gives empty")]
+        public void Test_slice_negative_start_after_negative_end_gives_empty()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("abcde", -1, -3));
+        }  // void Test_slice_negative_start_after_negative_end_gives_empty
+
+        [Test, Description("'abcde'[5:5] gives '': start equal to end gives empty")]
+        public void Test_slice_start_equal_to_end_gives_empty()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("abcde", 5, 5));
+        }  // void Test_slice_start_equal_to_end_gives_empty
+
+        [Test, Description("''[0:0] gives '': empty text")]
+        public void Test_slice_empty_text()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("", 0, 0));
+        }  // void Test_slice_empty_text
+
+        [Test, Description("''[-1:] gives '': negative start on empty text")]
+        public void Test_slice_negative_start_on_empty_text()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("", -1));
+        }  // void Test_slice_negative_start_on_empty_text
+
+        [Test, Description("''[:5] gives '': end beyond the end of empty text")]
+        public void Test_slice_end_beyond_the_end_of_empty_text()
+        {
+            Assert.AreEqual(
+                "",
+                Our.Common.StringHelpers.Slice("", 0, 5));
+        }  // void Test_slice_end_beyond_the_end_of_empty_text
+
+        [Test, Description("'é-x'[1:] gives '-x': after a character of two UTF-8 bytes")]
+        public void Test_slice_after_a_character_of_two_UTF_8_bytes()
+        {
+            Assert.AreEqual(
+                "-x",
+                Our.Common.StringHelpers.Slice("é-x", 1));
+        }  // void Test_slice_after_a_character_of_two_UTF_8_bytes
+
+        [Test, Description("'aéb'[1:2] gives 'é': character of two UTF-8 bytes")]
+        public void Test_slice_character_of_two_UTF_8_bytes()
+        {
+            Assert.AreEqual(
+                "é",
+                Our.Common.StringHelpers.Slice("aéb", 1, 2));
+        }  // void Test_slice_character_of_two_UTF_8_bytes
+
+        [Test, Description("'a😀b'[1:2] gives '😀': character beyond the Basic Multilingual Plane")]
+        public void Test_slice_character_beyond_the_Basic_Multilingual_Plane()
+        {
+            Assert.AreEqual(
+                "😀",
+                Our.Common.StringHelpers.Slice("a😀b", 1, 2));
+        }  // void Test_slice_character_beyond_the_Basic_Multilingual_Plane
+
+        [Test, Description("'😀-x'[1:] gives '-x': after a character beyond the Basic Multilingual Plane")]
+        public void Test_slice_after_a_character_beyond_the_Basic_Multilingual_Plane()
+        {
+            Assert.AreEqual(
+                "-x",
+                Our.Common.StringHelpers.Slice("😀-x", 1));
+        }  // void Test_slice_after_a_character_beyond_the_Basic_Multilingual_Plane
+
+        [Test, Description("'aé😀b😀'[-3:-1] gives '😀b': negative start on characters beyond ASCII")]
+        public void Test_slice_negative_start_on_characters_beyond_ASCII()
+        {
+            Assert.AreEqual(
+                "😀b",
+                Our.Common.StringHelpers.Slice("aé😀b😀", -3, -1));
+        }  // void Test_slice_negative_start_on_characters_beyond_ASCII
+
+        [Test, Description("'abcabc'.find('b') gives 1: found")]
+        public void Test_find_found()
+        {
+            Assert.AreEqual(
+                1,
+                Our.Common.StringHelpers.Find("abcabc", "b"));
+        }  // void Test_find_found
+
+        [Test, Description("'abcabc'.find('x') gives -1: not found")]
+        public void Test_find_not_found()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("abcabc", "x"));
+        }  // void Test_find_not_found
+
+        [Test, Description("'abcabc'.find('') gives 0: empty sub")]
+        public void Test_find_empty_sub()
+        {
+            Assert.AreEqual(
+                0,
+                Our.Common.StringHelpers.Find("abcabc", ""));
+        }  // void Test_find_empty_sub
+
+        [Test, Description("'ab'.find('abc') gives -1: sub longer than text")]
+        public void Test_find_sub_longer_than_text()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("ab", "abc"));
+        }  // void Test_find_sub_longer_than_text
+
+        [Test, Description("'abcabc'.find('b', 2) gives 4: found after start")]
+        public void Test_find_found_after_start()
+        {
+            Assert.AreEqual(
+                4,
+                Our.Common.StringHelpers.Find("abcabc", "b", 2));
+        }  // void Test_find_found_after_start
+
+        [Test, Description("'abcabc'.find('b', 5) gives -1: found only before start")]
+        public void Test_find_found_only_before_start()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("abcabc", "b", 5));
+        }  // void Test_find_found_only_before_start
+
+        [Test, Description("'abcabc'.find('c', -1) gives 5: negative start counts from the end")]
+        public void Test_find_negative_start_counts_from_the_end()
+        {
+            Assert.AreEqual(
+                5,
+                Our.Common.StringHelpers.Find("abcabc", "c", -1));
+        }  // void Test_find_negative_start_counts_from_the_end
+
+        [Test, Description("'abcabc'.find('a', -3) gives 3: negative start finds the later occurrence")]
+        public void Test_find_negative_start_finds_the_later_occurrence()
+        {
+            Assert.AreEqual(
+                3,
+                Our.Common.StringHelpers.Find("abcabc", "a", -3));
+        }  // void Test_find_negative_start_finds_the_later_occurrence
+
+        [Test, Description("'abcabc'.find('a', -10) gives 0: negative start before the beginning is clamped")]
+        public void Test_find_negative_start_before_the_beginning_is_clamped()
+        {
+            Assert.AreEqual(
+                0,
+                Our.Common.StringHelpers.Find("abcabc", "a", -10));
+        }  // void Test_find_negative_start_before_the_beginning_is_clamped
+
+        [Test, Description("'abcabc'.find('', 6) gives 6: empty sub at the end")]
+        public void Test_find_empty_sub_at_the_end()
+        {
+            Assert.AreEqual(
+                6,
+                Our.Common.StringHelpers.Find("abcabc", "", 6));
+        }  // void Test_find_empty_sub_at_the_end
+
+        [Test, Description("'abcabc'.find('', 7) gives -1: empty sub beyond the end gives -1")]
+        public void Test_find_empty_sub_beyond_the_end_gives_1()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("abcabc", "", 7));
+        }  // void Test_find_empty_sub_beyond_the_end_gives_1
+
+        [Test, Description("'abcabc'.find('c', 10) gives -1: start beyond the end gives -1")]
+        public void Test_find_start_beyond_the_end_gives_1()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("abcabc", "c", 10));
+        }  // void Test_find_start_beyond_the_end_gives_1
+
+        [Test, Description("''.find('') gives 0: empty sub in empty text")]
+        public void Test_find_empty_sub_in_empty_text()
+        {
+            Assert.AreEqual(
+                0,
+                Our.Common.StringHelpers.Find("", ""));
+        }  // void Test_find_empty_sub_in_empty_text
+
+        [Test, Description("''.find('', 1) gives -1: empty sub beyond the end of empty text gives -1")]
+        public void Test_find_empty_sub_beyond_the_end_of_empty_text_gives_1()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("", "", 1));
+        }  // void Test_find_empty_sub_beyond_the_end_of_empty_text_gives_1
+
+        [Test, Description("''.find('x') gives -1: not found in empty text")]
+        public void Test_find_not_found_in_empty_text()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("", "x"));
+        }  // void Test_find_not_found_in_empty_text
+
+        [Test, Description("'é-'.find('-') gives 1: after a character of two UTF-8 bytes")]
+        public void Test_find_after_a_character_of_two_UTF_8_bytes()
+        {
+            Assert.AreEqual(
+                1,
+                Our.Common.StringHelpers.Find("é-", "-"));
+        }  // void Test_find_after_a_character_of_two_UTF_8_bytes
+
+        [Test, Description("'😀-'.find('-') gives 1: after a character beyond the Basic Multilingual Plane")]
+        public void Test_find_after_a_character_beyond_the_Basic_Multilingual_Plane()
+        {
+            Assert.AreEqual(
+                1,
+                Our.Common.StringHelpers.Find("😀-", "-"));
+        }  // void Test_find_after_a_character_beyond_the_Basic_Multilingual_Plane
+
+        [Test, Description("'a😀b'.find('😀') gives 1: character beyond the Basic Multilingual Plane")]
+        public void Test_find_character_beyond_the_Basic_Multilingual_Plane()
+        {
+            Assert.AreEqual(
+                1,
+                Our.Common.StringHelpers.Find("a😀b", "😀"));
+        }  // void Test_find_character_beyond_the_Basic_Multilingual_Plane
+
+        [Test, Description("'😀a😀a'.find('a', 2) gives 3: start after a character beyond ASCII")]
+        public void Test_find_start_after_a_character_beyond_ASCII()
+        {
+            Assert.AreEqual(
+                3,
+                Our.Common.StringHelpers.Find("😀a😀a", "a", 2));
+        }  // void Test_find_start_after_a_character_beyond_ASCII
+
+        [Test, Description("'😀a😀a'.find('😀', -2) gives 2: negative start on characters beyond ASCII")]
+        public void Test_find_negative_start_on_characters_beyond_ASCII()
+        {
+            Assert.AreEqual(
+                2,
+                Our.Common.StringHelpers.Find("😀a😀a", "😀", -2));
+        }  // void Test_find_negative_start_on_characters_beyond_ASCII
+
+        [Test, Description("'é😀'.find('', 3) gives -1: start beyond the end of characters beyond ASCII")]
+        public void Test_find_start_beyond_the_end_of_characters_beyond_ASCII()
+        {
+            Assert.AreEqual(
+                -1,
+                Our.Common.StringHelpers.Find("é😀", "", 3));
+        }  // void Test_find_start_beyond_the_end_of_characters_beyond_ASCII
+    }  // class TestStringHelpers
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestVerificationOfEnums.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestVerificationOfEnums.cs
new file mode 100644
index 000000000..3b939cb27
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestVerificationOfEnums.cs
@@ -0,0 +1,22 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using System.Linq;  // can't alias
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestVerificationOfEnums
+    {
+        
+    }  // class TestVerificationOfEnums
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXOrDefault.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXOrDefault.cs
new file mode 100644
index 000000000..ec2dcc3de
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXOrDefault.cs
@@ -0,0 +1,72 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Directory = System.IO.Directory;
+using Nodes = System.Text.Json.Nodes;
+using Path = System.IO.Path;
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestXOrDefault
+    {
+        private static void CompareOrRerecordValue(
+            object value,
+            string expectedPath)
+        {
+            Nodes.JsonNode got = Our.Tests.CommonJson.ToJson(
+                value);
+
+            if (Our.Tests.Common.RecordMode)
+            {
+                string? parent = Path.GetDirectoryName(expectedPath);
+                if (parent != null)
+                {
+                    if (!Directory.Exists(parent))
+                    {
+                        Directory.CreateDirectory(parent);
+                    }
+                }
+
+                System.IO.File.WriteAllText(
+                    expectedPath, got.ToJsonString());
+            }
+            else
+            {
+                if (!System.IO.File.Exists(expectedPath))
+                {
+                    throw new System.IO.FileNotFoundException(
+                        $"The file with the recorded value does not exist: {expectedPath}; " +
+                        "maybe you want to set the environment " +
+                        $"variable {Our.Tests.Common.RecordModeEnvironmentVariableName}?");
+                }
+
+                Nodes.JsonNode expected = Our.Tests.CommonJson.ReadFromFile(
+                    expectedPath);
+
+                Our.Tests.CommonJson.CheckJsonNodesEqual(
+                    expected, got, out Our.Reporting.Error? error);
+
+                if (error != null)
+                {
+                    Assert.Fail(
+                        $"The original value from {expectedPath} is unequal the obtain value " +
+                        "when serialized to JSON: " +
+                        $"{Reporting.GenerateJsonPath(error.PathSegments)}: " +
+                        error.Cause
+                    );
+                }
+            }
+        }
+    }  // class TestXOrDefault
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationErrors.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationErrors.cs
new file mode 100644
index 000000000..411be3173
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationErrors.cs
@@ -0,0 +1,156 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Path = System.IO.Path;
+
+using NUnit.Framework; // can't alias
+
+namespace dummy.Tests
+{
+    public class TestXmlizationErrors
+    {
+        [Test]
+        public void Test_error_on_unexpected_declaration()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Xml",
+                "Expected",
+                "someItem",
+                "minimal.xml");
+
+            var text = System.IO.File.ReadAllText(path, System.Text.Encoding.UTF8);
+
+            // We assume no XML declarations in our test data.
+            if (!text.StartsWith("<someItem "))
+            {
+                throw new System.InvalidOperationException(
+                    "We expect our test example in XML to start with '<someItem ', "
+                        + $"but it does not: {path}"
+                );
+            }
+
+            text = (
+                "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
+                    + text
+            );
+
+            using var stringReader = new System.IO.StringReader(
+                text);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                stringReader);
+
+            // We intentionally do not call `MoveToContent` to test the error message.
+            // This is a very common situation.
+
+            string? message = null;
+
+            try
+            {
+                Our.Xmlization.Deserialize.SomeItemFrom(
+                    xmlReader);
+            }
+            catch (Our.Xmlization.Exception exception)
+            {
+                message = exception.Message;
+            }
+
+            if (message == null)
+            {
+                throw new AssertionException("Unexpected no exception");
+            }
+            Assert.AreEqual(
+                "Unexpected XML declaration when reading an instance of " +
+                "class SomeItem, as we expect the reader to be set at content " +
+                "with MoveToContent at: the beginning",
+                message);
+        }
+
+        [Test]
+        public void Test_error_on_duplicate_property()
+        {
+            string path = Path.Combine(
+                Our.Tests.Common.TestDataDir,
+                "Xml",
+                "Expected",
+                "someItem",
+                "minimal.xml");
+
+            var text = System.IO.File.ReadAllText(path, System.Text.Encoding.UTF8);
+
+            // We cut the element of the property out of the recorded example and put it
+            // in a second time, just before the closing tag of the instance.
+            int start = text.IndexOf(
+                "<name>",
+                System.StringComparison.Ordinal);
+
+            string property;
+            if (start >= 0)
+            {
+                int end = text.IndexOf(
+                    "</name>",
+                    start,
+                    System.StringComparison.Ordinal);
+
+                property = text.Substring(start, end + 7 - start);
+            }
+            else
+            {
+                // The element is written self-closing in the example, an empty list being
+                // the usual reason. We write that very element out ourselves.
+                property = "<name/>";
+            }
+
+            int insertionIndex = text.LastIndexOf(
+                "</someItem>",
+                System.StringComparison.Ordinal);
+
+            if (insertionIndex < 0)
+            {
+                throw new System.InvalidOperationException(
+                    "We expect the recorded example to contain the closing tag "
+                        + $"</someItem>, but it does not: {path}");
+            }
+
+            string brokenText = (
+                text.Substring(0, insertionIndex)
+                    + property
+                    + text.Substring(insertionIndex));
+
+            using var stringReader = new System.IO.StringReader(
+                brokenText);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                stringReader);
+
+            string? message = null;
+
+            try
+            {
+                Our.Xmlization.Deserialize.SomeItemFrom(
+                    xmlReader);
+            }
+            catch (Our.Xmlization.Exception exception)
+            {
+                message = exception.Message;
+            }
+
+            if (message == null)
+            {
+                throw new AssertionException(
+                    "Expected an exception when the property "
+                        + "name is given twice, but got none");
+            }
+        }
+    }  // class TestXmlizationErrors
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfConcreteClasses.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfConcreteClasses.cs
new file mode 100644
index 000000000..26bc061f2
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfConcreteClasses.cs
@@ -0,0 +1,703 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using Directory = System.IO.Directory;
+using Path = System.IO.Path;
+
+using NUnit.Framework; // can't alias
+using System.Linq;  // can't alias
+using System.Xml.Linq; // can't alias
+
+namespace dummy.Tests
+{
+    public class TestXmlizationOfConcreteClasses
+    {
+        private static void CheckElementsEqual(
+            XElement expected,
+            XElement got,
+            out Reporting.Error? error)
+        {
+            error = null;
+
+            if (expected.Name.LocalName != got.Name.LocalName)
+            {
+                error = new Reporting.Error(
+                    "Mismatch in element names: " +
+                    $"{expected} != {got}"
+                );
+                return;
+            }
+
+            string? expectedContent = (expected.FirstNode as XText)?.Value;
+            string? gotContent = (got.FirstNode as XText)?.Value;
+
+            if (expectedContent != gotContent)
+            {
+                error = new Reporting.Error(
+                    $"Mismatch in element contents: {expected} != {got}"
+                );
+                return;
+            }
+
+            var expectedChildren = expected.Elements().ToList();
+            var gotChildren = got.Elements().ToList();
+
+            if (expectedChildren.Count != gotChildren.Count)
+            {
+                error = new Reporting.Error(
+                    $"Mismatch in child elements: {expected} != {got}"
+                );
+                return;
+            }
+
+            for (int i = 0; i < expectedChildren.Count; i++)
+            {
+                CheckElementsEqual(
+                    expectedChildren[i],
+                    gotChildren[i],
+                    out error);
+
+                if (error != null)
+                {
+                    error.PrependSegment(
+                        new Reporting.IndexSegment(i));
+
+                    error.PrependSegment(
+                        new Reporting.NameSegment(
+                            expected.Name.ToString()));
+                }
+            }
+        }
+
+        private static void AssertSerializeDeserializeEqualsOriginal(
+            Our.IClass instance, string path)
+        {
+            // Serialize
+            var outputBuilder = new System.Text.StringBuilder();
+
+            {
+                using var writer = System.Xml.XmlWriter.Create(
+                    outputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    }
+                );
+                Our.Xmlization.Serialize.To(
+                    instance,
+                    writer);
+            }
+
+            string outputText = outputBuilder.ToString();
+
+            // Compare input == output
+            {
+                using var outputReader = new System.IO.StringReader(outputText);
+                var gotDoc = XDocument.Load(outputReader);
+
+                Assert.AreEqual(
+                    gotDoc.Root?.Name.Namespace.ToString(),
+                    "https://dummy.com");
+
+                foreach (var child in gotDoc.Descendants())
+                {
+                    Assert.IsTrue(
+                        child.GetDefaultNamespace().NamespaceName == "https://dummy.com",
+                        $"Unexpected namespace of {child.Name}: " +
+                            $"{child.GetDefaultNamespace().NamespaceName}");
+                }
+
+                var expectedDoc = XDocument.Load(path);
+
+                CheckElementsEqual(
+                    expectedDoc.Root!,
+                    gotDoc.Root!,
+                    out Reporting.Error? inequalityError);
+
+                if (inequalityError != null)
+                {
+                    Assert.Fail(
+                        $"The original XML from {path} is unequal the serialized XML: " +
+                        $"#/{Reporting.GenerateRelativeXPath(inequalityError.PathSegments)}: " +
+                        inequalityError.Cause
+                    );
+                }
+            }
+        }
+
+        private static void AssertEqualsExpectedOrRerecordDeserializationException(
+            Our.Xmlization.Exception? exception,
+            string path)
+        {
+            if (exception == null)
+            {
+                Assert.Fail(
+                    $"Expected a Xmlization exception when de-serializing {path}, but got none."
+                );
+            }
+            else
+            {
+                string exceptionPath = path + ".exception";
+                string got = exception.Message;
+                if (Our.Tests.Common.RecordMode)
+                {
+                    System.IO.File.WriteAllText(exceptionPath, got);
+                }
+                else
+                {
+                    if (!System.IO.File.Exists(exceptionPath))
+                    {
+                        throw new System.IO.FileNotFoundException(
+                            "The file with the recorded exception does not " +
+                            $"exist: {exceptionPath}; maybe you want to set the environment " +
+                            $"variable {Our.Tests.Common.RecordModeEnvironmentVariableName}?");
+                    }
+
+                    string expected = System.IO.File.ReadAllText(exceptionPath);
+                    Assert.AreEqual(
+                        expected.Replace("\r\n", "\n"),
+                        got.Replace("\r\n", "\n"),
+                        $"The expected exception does not match the actual one for the file {path}");
+                }
+            }
+        }
+
+        [Test]
+        public void Test_SomeItem_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Xml",
+                    "Expected",
+                    "someItem"
+                ),
+                "*.xml",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                using var xmlReader = System.Xml.XmlReader.Create(path);
+                xmlReader.MoveToContent();
+
+                var instance = Our.Xmlization.Deserialize.SomeItemFrom(
+                    xmlReader);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    instance, path);
+            }
+        }  // public void Test_SomeItem_ok
+
+        [Test]
+        public void Test_SomeItem_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "someItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SomeItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    Our.Xmlization.Exception? exception = null;
+
+                    try
+                    {
+                        _ = Our.Xmlization.Deserialize.SomeItemFrom(
+                            xmlReader);
+                    }
+                    catch (Our.Xmlization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_SomeItem_deserialization_fail
+
+        [Test]
+        public void Test_SomeItem_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "someItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SomeItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    var instance = Our.Xmlization.Deserialize.SomeItemFrom(
+                        xmlReader);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_SomeItem_verification_fail
+
+        [Test]
+        public void Test_SpecialItem_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Xml",
+                    "Expected",
+                    "specialItem"
+                ),
+                "*.xml",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                using var xmlReader = System.Xml.XmlReader.Create(path);
+                xmlReader.MoveToContent();
+
+                var instance = Our.Xmlization.Deserialize.SpecialItemFrom(
+                    xmlReader);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    instance, path);
+            }
+        }  // public void Test_SpecialItem_ok
+
+        [Test]
+        public void Test_SpecialItem_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "specialItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SpecialItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    Our.Xmlization.Exception? exception = null;
+
+                    try
+                    {
+                        _ = Our.Xmlization.Deserialize.SpecialItemFrom(
+                            xmlReader);
+                    }
+                    catch (Our.Xmlization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_SpecialItem_deserialization_fail
+
+        [Test]
+        public void Test_SpecialItem_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "specialItem"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of SpecialItem for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    var instance = Our.Xmlization.Deserialize.SpecialItemFrom(
+                        xmlReader);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_SpecialItem_verification_fail
+
+        [Test]
+        public void Test_Container_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Xml",
+                    "Expected",
+                    "container"
+                ),
+                "*.xml",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                using var xmlReader = System.Xml.XmlReader.Create(path);
+                xmlReader.MoveToContent();
+
+                var instance = Our.Xmlization.Deserialize.ContainerFrom(
+                    xmlReader);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    instance, path);
+            }
+        }  // public void Test_Container_ok
+
+        [Test]
+        public void Test_Container_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "container"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Container for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    Our.Xmlization.Exception? exception = null;
+
+                    try
+                    {
+                        _ = Our.Xmlization.Deserialize.ContainerFrom(
+                            xmlReader);
+                    }
+                    catch (Our.Xmlization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_Container_deserialization_fail
+
+        [Test]
+        public void Test_Container_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "container"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Container for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    var instance = Our.Xmlization.Deserialize.ContainerFrom(
+                        xmlReader);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_Container_verification_fail
+
+        [Test]
+        public void Test_Wrapper_ok()
+        {
+            var paths = Directory.GetFiles(
+                Path.Combine(
+                    Our.Tests.Common.TestDataDir,
+                    "Xml",
+                    "Expected",
+                    "wrapper"
+                ),
+                "*.xml",
+                System.IO.SearchOption.AllDirectories).ToList();
+            paths.Sort();
+
+            foreach (var path in paths)
+            {
+                using var xmlReader = System.Xml.XmlReader.Create(path);
+                xmlReader.MoveToContent();
+
+                var instance = Our.Xmlization.Deserialize.WrapperFrom(
+                    xmlReader);
+
+                var errors = Our.Verification.Verify(instance).ToList();
+                Our.Tests.Common.AssertNoVerificationErrors(errors, path);
+
+                AssertSerializeDeserializeEqualsOriginal(
+                    instance, path);
+            }
+        }  // public void Test_Wrapper_ok
+
+        [Test]
+        public void Test_Wrapper_deserialization_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Unserializable"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "wrapper"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Wrapper for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    Our.Xmlization.Exception? exception = null;
+
+                    try
+                    {
+                        _ = Our.Xmlization.Deserialize.WrapperFrom(
+                            xmlReader);
+                    }
+                    catch (Our.Xmlization.Exception observedException)
+                    {
+                        exception = observedException;
+                    }
+
+                    AssertEqualsExpectedOrRerecordDeserializationException(
+                        exception, path);
+                }
+            }
+        }  // public void Test_Wrapper_deserialization_fail
+
+        [Test]
+        public void Test_Wrapper_verification_fail()
+        {
+            foreach (
+                string causeDir in
+                Directory.GetDirectories(
+                    Path.Combine(
+                        Our.Tests.Common.TestDataDir,
+                        "Xml",
+                        "Unexpected",
+                        "Invalid"
+                    )
+                )
+            )
+            {
+                string clsDir = Path.Combine(
+                    causeDir,
+                    "wrapper"
+                );
+
+                if (!Directory.Exists(clsDir))
+                {
+                    // No examples of Wrapper for the failure cause.
+                    continue;
+                }
+
+                var paths = Directory.GetFiles(
+                    clsDir,
+                    "*.xml",
+                    System.IO.SearchOption.AllDirectories).ToList();
+                paths.Sort();
+
+                foreach (var path in paths)
+                {
+                    using var xmlReader = System.Xml.XmlReader.Create(path);
+                    xmlReader.MoveToContent();
+
+                    var instance = Our.Xmlization.Deserialize.WrapperFrom(
+                        xmlReader);
+
+                    var errors = Our.Verification.Verify(instance).ToList();
+                    Our.Tests.Common.AssertEqualsExpectedOrRerecordVerificationErrors(
+                        errors, path);
+                }
+            }
+        }  // public void Test_Wrapper_verification_fail
+    }  // class TestXmlizationOfConcreteClasses
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfInterfaces.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfInterfaces.cs
new file mode 100644
index 000000000..df712b72e
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy.Tests/TestXmlizationOfInterfaces.cs
@@ -0,0 +1,251 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+
+using NUnit.Framework;  // can't alias
+
+namespace dummy.Tests
+{
+    public class TestXmlizationOfInterfaces
+    {
+        [Test]
+        public void Test_round_trip_IItem_from_SomeItem()
+        {
+            // We load from JSON here just to jump-start the round trip.
+            // The round-trip goes then over XML.
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSomeItem();
+
+            // The round-trip starts here.
+            var outputBuilder = new System.Text.StringBuilder();
+
+            // Serialize to XML
+            {
+                using var xmlWriter = System.Xml.XmlWriter.Create(
+                    outputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    instance,
+                    xmlWriter);
+            }
+
+            // De-serialize from XML
+            string outputText = outputBuilder.ToString();
+
+            using var outputReader = new System.IO.StringReader(outputText);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                outputReader,
+                new System.Xml.XmlReaderSettings());
+
+            var anotherInstance = Our.Xmlization.Deserialize.IItemFrom(
+                xmlReader);
+
+            // Serialize back to XML
+            var anotherOutputBuilder = new System.Text.StringBuilder();
+
+            {
+                using var anotherXmlWriter = System.Xml.XmlWriter.Create(
+                    anotherOutputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    anotherInstance,
+                    anotherXmlWriter);
+            }
+
+            // Compare
+            Assert.AreEqual(outputText, anotherOutputBuilder.ToString());
+        }  // void Test_round_trip_IItem_from_SomeItem
+
+        [Test]
+        public void Test_round_trip_IItem_from_SpecialItem()
+        {
+            // We load from JSON here just to jump-start the round trip.
+            // The round-trip goes then over XML.
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSpecialItem();
+
+            // The round-trip starts here.
+            var outputBuilder = new System.Text.StringBuilder();
+
+            // Serialize to XML
+            {
+                using var xmlWriter = System.Xml.XmlWriter.Create(
+                    outputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    instance,
+                    xmlWriter);
+            }
+
+            // De-serialize from XML
+            string outputText = outputBuilder.ToString();
+
+            using var outputReader = new System.IO.StringReader(outputText);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                outputReader,
+                new System.Xml.XmlReaderSettings());
+
+            var anotherInstance = Our.Xmlization.Deserialize.IItemFrom(
+                xmlReader);
+
+            // Serialize back to XML
+            var anotherOutputBuilder = new System.Text.StringBuilder();
+
+            {
+                using var anotherXmlWriter = System.Xml.XmlWriter.Create(
+                    anotherOutputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    anotherInstance,
+                    anotherXmlWriter);
+            }
+
+            // Compare
+            Assert.AreEqual(outputText, anotherOutputBuilder.ToString());
+        }  // void Test_round_trip_IItem_from_SpecialItem
+
+        [Test]
+        public void Test_round_trip_ISomeItem_from_SpecialItem()
+        {
+            // We load from JSON here just to jump-start the round trip.
+            // The round-trip goes then over XML.
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSpecialItem();
+
+            // The round-trip starts here.
+            var outputBuilder = new System.Text.StringBuilder();
+
+            // Serialize to XML
+            {
+                using var xmlWriter = System.Xml.XmlWriter.Create(
+                    outputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    instance,
+                    xmlWriter);
+            }
+
+            // De-serialize from XML
+            string outputText = outputBuilder.ToString();
+
+            using var outputReader = new System.IO.StringReader(outputText);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                outputReader,
+                new System.Xml.XmlReaderSettings());
+
+            var anotherInstance = Our.Xmlization.Deserialize.ISomeItemFrom(
+                xmlReader);
+
+            // Serialize back to XML
+            var anotherOutputBuilder = new System.Text.StringBuilder();
+
+            {
+                using var anotherXmlWriter = System.Xml.XmlWriter.Create(
+                    anotherOutputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    anotherInstance,
+                    anotherXmlWriter);
+            }
+
+            // Compare
+            Assert.AreEqual(outputText, anotherOutputBuilder.ToString());
+        }  // void Test_round_trip_ISomeItem_from_SpecialItem
+
+        [Test]
+        public void Test_round_trip_ISomeItem_from_SomeItem()
+        {
+            // We load from JSON here just to jump-start the round trip.
+            // The round-trip goes then over XML.
+            var instance = Our.Tests.CommonJsonization.LoadMaximalSomeItem();
+
+            // The round-trip starts here.
+            var outputBuilder = new System.Text.StringBuilder();
+
+            // Serialize to XML
+            {
+                using var xmlWriter = System.Xml.XmlWriter.Create(
+                    outputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    instance,
+                    xmlWriter);
+            }
+
+            // De-serialize from XML
+            string outputText = outputBuilder.ToString();
+
+            using var outputReader = new System.IO.StringReader(outputText);
+
+            using var xmlReader = System.Xml.XmlReader.Create(
+                outputReader,
+                new System.Xml.XmlReaderSettings());
+
+            var anotherInstance = Our.Xmlization.Deserialize.ISomeItemFrom(
+                xmlReader);
+
+            // Serialize back to XML
+            var anotherOutputBuilder = new System.Text.StringBuilder();
+
+            {
+                using var anotherXmlWriter = System.Xml.XmlWriter.Create(
+                    anotherOutputBuilder,
+                    new System.Xml.XmlWriterSettings()
+                    {
+                        Encoding = System.Text.Encoding.UTF8,
+                        OmitXmlDeclaration = true
+                    });
+
+                Our.Xmlization.Serialize.To(
+                    anotherInstance,
+                    anotherXmlWriter);
+            }
+
+            // Compare
+            Assert.AreEqual(outputText, anotherOutputBuilder.ToString());
+        }  // void Test_round_trip_ISomeItem_from_SomeItem
+    }  // class TestXmlizationOfInterfaces
+}  // namespace dummy.Tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/common.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/common.cs
new file mode 100644
index 000000000..0d82a8272
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/common.cs
@@ -0,0 +1,199 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide the helpers shared by the transpiled code in the other modules.
+    /// </summary>
+    public static class Common
+    {
+        /// <summary>
+        /// Provide operations on tuples.
+        /// </summary>
+        public static class TupleHelpers
+        {
+            /// <summary>
+            /// Count the items of <paramref name="tuple" />.
+            /// </summary>
+            public static int Len(System.Runtime.CompilerServices.ITuple tuple)
+            {
+                return tuple.Length;
+            }
+        }  // public static class TupleHelpers
+
+        /// <summary>
+        /// Provide string operations which follow the Python implementation, since
+        /// Python is the language of the meta-model specifications.
+        /// </summary>
+        /// <remarks>
+        /// The lengths and the positions count the characters (code points), and not
+        /// the UTF-16 code units of the C# strings. Hence, a character beyond the Basic
+        /// Multilingual Plane counts as one, though it takes two UTF-16 code units
+        /// (a surrogate pair).
+        /// </remarks>
+        public static class StringHelpers
+        {
+            /// <summary>
+            /// Check whether a surrogate pair starts at <paramref name="offset" />
+            /// in <paramref name="text" />.
+            /// </summary>
+            private static bool IsSurrogatePairAt(string text, int offset)
+            {
+                return (
+                    offset + 1 < text.Length
+                    && char.IsHighSurrogate(text[offset])
+                    && char.IsLowSurrogate(text[offset + 1])
+                );
+            }
+
+            /// <summary>
+            /// Count the characters of <paramref name="text" /> between the UTF-16
+            /// offsets <paramref name="startOffset" /> and <paramref name="endOffset" />.
+            /// </summary>
+            private static int CountCharacters(
+                string text,
+                int startOffset,
+                int endOffset
+            )
+            {
+                int count = 0;
+                int offset = startOffset;
+                while (offset < endOffset)
+                {
+                    offset += IsSurrogatePairAt(text, offset) ? 2 : 1;
+                    count++;
+                }
+
+                return count;
+            }
+
+            /// <summary>
+            /// Compute the UTF-16 offset of the character at <paramref name="position" />
+            /// in <paramref name="text" />.
+            /// </summary>
+            private static int OffsetOf(string text, int position)
+            {
+                int offset = 0;
+                for (int i = 0; i < position; i++)
+                {
+                    offset += IsSurrogatePairAt(text, offset) ? 2 : 1;
+                }
+
+                return offset;
+            }
+
+            /// <summary>
+            /// Resolve <paramref name="position" /> in a string of
+            /// <paramref name="length" /> as Python does in slicing.
+            /// </summary>
+            /// <remarks>
+            /// A negative position counts from the end, and the positions out of range
+            /// are clamped to the string.
+            /// </remarks>
+            private static int ResolvePosition(long position, int length)
+            {
+                if (position < 0)
+                {
+                    return (int)System.Math.Max(position + length, 0);
+                }
+
+                return (int)System.Math.Min(position, length);
+            }
+
+            /// <summary>
+            /// Count the characters (code points) of <paramref name="text" />.
+            /// </summary>
+            /// <remarks>
+            /// We follow the Python implementation of <c>len</c>, since Python is
+            /// the language of the meta-model specifications. Hence, a character beyond
+            /// the Basic Multilingual Plane counts as one, unlike in <c>text.Length</c>.
+            /// </remarks>
+            public static int Len(string text)
+            {
+                return CountCharacters(text, 0, text.Length);
+            }
+
+            /// <summary>
+            /// Slice <paramref name="text" /> from <paramref name="start" /> up to
+            /// <paramref name="end" />, exclusive.
+            /// </summary>
+            /// <remarks>
+            /// We follow the Python implementation of slicing, since Python is
+            /// the language of the meta-model specifications. Hence, the positions count
+            /// the characters (code points), a negative position counts from the end,
+            /// the positions out of range are clamped to the string, and the slice is
+            /// empty if <paramref name="start" /> is not before <paramref name="end" />.
+            /// If <paramref name="end" /> is not given, we slice up to the end of
+            /// <paramref name="text" />.
+            /// </remarks>
+            public static string Slice(string text, long start, long? end = null)
+            {
+                int length = Len(text);
+                int theStart = ResolvePosition(start, length);
+                int theEnd = end is null
+                    ? length
+                    : ResolvePosition(end.Value, length);
+
+                if (theStart >= theEnd)
+                {
+                    return "";
+                }
+
+                int startOffset = OffsetOf(text, theStart);
+                int endOffset = OffsetOf(text, theEnd);
+                return text.Substring(startOffset, endOffset - startOffset);
+            }
+
+            /// <summary>
+            /// Find the first <paramref name="sub" /> in <paramref name="text" /> from
+            /// <paramref name="start" /> on.
+            /// </summary>
+            /// <remarks>
+            /// We follow the Python implementation of <c>str.find</c>, since Python is
+            /// the language of the meta-model specifications. Hence, the positions count
+            /// the characters (code points), a negative <paramref name="start" /> counts
+            /// from the end, and a <paramref name="start" /> beyond the end of
+            /// <paramref name="text" /> gives -1. We compare the strings ordinally.
+            /// </remarks>
+            /// <returns>
+            /// The position of <paramref name="sub" /> in <paramref name="text" />,
+            /// or -1 if not found
+            /// </returns>
+            public static long Find(string text, string sub, long start = 0)
+            {
+                int length = Len(text);
+                long theStart = start < 0
+                    ? System.Math.Max(start + length, 0)
+                    : start;
+
+                if (theStart > length)
+                {
+                    return -1;
+                }
+
+                int startOffset = OffsetOf(text, (int)theStart);
+                int offset = text.IndexOf(
+                    sub,
+                    startOffset,
+                    System.StringComparison.Ordinal
+                );
+
+                if (offset == -1)
+                {
+                    return -1;
+                }
+
+                return theStart + CountCharacters(text, startOffset, offset);
+            }
+        }  // public static class StringHelpers
+    }  // public static class Common
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/constants.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/constants.cs
new file mode 100644
index 000000000..e89d2649f
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/constants.cs
@@ -0,0 +1,22 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide constant values of the meta-model.
+    /// </summary>
+    public static class Constants
+    {
+
+    }  // public static class Constants
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/copying.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/copying.cs
new file mode 100644
index 000000000..30cfc4469
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/copying.cs
@@ -0,0 +1,178 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Allow for making shallow and deep copies of model instances.
+    /// </summary>
+    public static class Copying
+    {
+        private static readonly ShallowCopier ShallowCopierInstance = (
+            new ShallowCopier());
+
+        private static readonly DeepCopier DeepCopierInstance = (
+            new DeepCopier());
+
+        /// <summary>
+        /// Make a shallow copy of <paramref name="that" />.
+        /// </summary>
+        /// <remarks>
+        /// All the properties are copied by reference. This includes also the lists.
+        /// Hence, a list property is copied by reference, and not, as sometimes might be
+        /// expected, as a new list of underlying references.
+        /// </remarks>.
+        /// <param name="that">to be copied in a shallow manner</param>
+        /// <typeparam name="T">type to cast the result to</typeparam>
+        public static T Shallow<T>(T that) where T : Our.IClass
+        {
+            return (T)ShallowCopierInstance.Transform(that);
+        }
+
+        /// <summary>
+        /// Make a recursively a deep copy of <paramref name="that" />.
+        /// </summary>
+        /// <param name="that">to be deeply copied in a recursive manner</param>
+        /// <typeparam name="T">type to cast the result to</typeparam>
+        public static T Deep<T>(T that) where T : Our.IClass
+        {
+            return (T)DeepCopierInstance.Transform(that);
+        }
+
+        /// <summary>
+        /// Make a deep copy of <paramref name="that" />.
+        /// </summary>
+        private static List<IItem> Deep_ListOf_IItem(
+            List<IItem> that)
+        {
+            var result = new List<IItem>(that.Count);
+            foreach (var item in that)
+            {
+                result.Add(Deep(item));
+            }
+
+            return result;
+        }
+
+        /// <summary>
+        /// Make a deep copy of <paramref name="that" />.
+        /// </summary>
+        private static List<ISomeItem> Deep_ListOf_ISomeItem(
+            List<ISomeItem> that)
+        {
+            var result = new List<ISomeItem>(that.Count);
+            foreach (var item in that)
+            {
+                result.Add(Deep(item));
+            }
+
+            return result;
+        }
+
+        /// <summary>
+        /// Make a deep copy of <paramref name="that" />.
+        /// </summary>
+        private static List<ISpecialItem> Deep_ListOf_ISpecialItem(
+            List<ISpecialItem> that)
+        {
+            var result = new List<ISpecialItem>(that.Count);
+            foreach (var item in that)
+            {
+                result.Add(Deep(item));
+            }
+
+            return result;
+        }
+
+        /// <summary>Dispatch the making of shallow copies.</summary>
+        internal class ShallowCopier : Visitation.AbstractTransformer<Our.IClass>
+        {
+            public override Our.IClass TransformSomeItem(
+                Our.ISomeItem that
+            )
+            {
+                return new Our.SomeItem(that.Name, that.Nickname);
+            }
+
+            public override Our.IClass TransformSpecialItem(
+                Our.ISpecialItem that
+            )
+            {
+                return new Our.SpecialItem(that.Name, that.Level, that.Nickname);
+            }
+
+            public override Our.IClass TransformContainer(
+                Our.IContainer that
+            )
+            {
+                return new Our.Container(
+                    that.Items,
+                    that.SomeItems,
+                    that.SpecialItems);
+            }
+
+            public override Our.IClass TransformWrapper(
+                Our.IWrapper that
+            )
+            {
+                return new Our.Wrapper(that.Container);
+            }
+        }  // internal class ShallowCopier
+
+        /// <summary>Dispatch the making of deep copies.</summary>
+        internal class DeepCopier : Visitation.AbstractTransformer<Our.IClass>
+        {    public override Our.IClass TransformSomeItem(
+                Our.ISomeItem that
+            )
+            {
+                return new Our.SomeItem(
+                    that.Name,
+                    that.Nickname
+                );
+            }
+
+            public override Our.IClass TransformSpecialItem(
+                Our.ISpecialItem that
+            )
+            {
+                return new Our.SpecialItem(
+                    that.Name,
+                    that.Level,
+                    that.Nickname
+                );
+            }
+
+            public override Our.IClass TransformContainer(
+                Our.IContainer that
+            )
+            {
+                return new Our.Container(
+                    Deep_ListOf_IItem(that.Items),
+                    Deep_ListOf_ISomeItem(that.SomeItems),
+                    (that.SpecialItems != null)
+                        ? Deep_ListOf_ISpecialItem(that.SpecialItems)
+                        : null
+                );
+            }
+
+            public override Our.IClass TransformWrapper(
+                Our.IWrapper that
+            )
+            {
+                return new Our.Wrapper(
+                    Deep(that.Container)
+                );
+            }
+        }  // internal class DeepCopier
+    }  // public static class Copying
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/enhancing.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/enhancing.cs
new file mode 100644
index 000000000..1f3c3e86f
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/enhancing.cs
@@ -0,0 +1,565 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Allow for enhancing of our model classes with custom wraps.
+    /// </summary>
+    public static class Enhancing
+    {
+        public abstract class Enhanced<TEnhancement> where TEnhancement : class
+        {
+            // ReSharper disable once InconsistentNaming
+            protected readonly TEnhancement _enhancement;
+
+            protected Enhanced(TEnhancement enhancement)
+            {
+                _enhancement = enhancement;
+            }
+
+            internal TEnhancement _getEnhancement()
+            {
+                return _enhancement;
+            }
+        }
+
+        public class EnhancedSomeItem<TEnhancement>
+            : Enhanced<TEnhancement>, Our.ISomeItem
+            where TEnhancement : class
+        {
+            private readonly Our.ISomeItem _instance;
+
+            public EnhancedSomeItem(
+                Our.ISomeItem instance,
+                TEnhancement enhancement
+            ) : base(enhancement)
+            {
+                _instance = instance;
+            }
+
+            public string Name
+            {
+                get => _instance.Name;
+                set => _instance.Name = value;
+            }
+
+            public string? Nickname
+            {
+                get => _instance.Nickname;
+                set => _instance.Nickname = value;
+            }
+
+            public IEnumerable<Our.IClass> DescendOnce()
+            {
+                return _instance.DescendOnce();
+            }
+
+            public IEnumerable<Our.IClass> Descend()
+            {
+                return _instance.Descend();
+            }
+
+            public void Accept(Our.Visitation.IVisitor visitor)
+            {
+                visitor.VisitSomeItem(_instance);
+            }
+
+            public void Accept<TContext>(
+                Visitation.IVisitorWithContext<TContext> visitor,
+                TContext context
+            )
+            {
+                visitor.VisitSomeItem(_instance, context);
+            }
+
+            public T Transform<T>(Visitation.ITransformer<T> transformer)
+            {
+                return transformer.TransformSomeItem(_instance);
+            }
+
+            public T Transform<TContext, T>(
+                Visitation.ITransformerWithContext<TContext, T> transformer,
+                TContext context
+            )
+            {
+                return transformer.TransformSomeItem(_instance, context);
+            }
+        }
+
+        public class EnhancedSpecialItem<TEnhancement>
+            : Enhanced<TEnhancement>, Our.ISpecialItem
+            where TEnhancement : class
+        {
+            private readonly Our.ISpecialItem _instance;
+
+            public EnhancedSpecialItem(
+                Our.ISpecialItem instance,
+                TEnhancement enhancement
+            ) : base(enhancement)
+            {
+                _instance = instance;
+            }
+
+            public string Name
+            {
+                get => _instance.Name;
+                set => _instance.Name = value;
+            }
+
+            public string? Nickname
+            {
+                get => _instance.Nickname;
+                set => _instance.Nickname = value;
+            }
+
+            public long Level
+            {
+                get => _instance.Level;
+                set => _instance.Level = value;
+            }
+
+            public IEnumerable<Our.IClass> DescendOnce()
+            {
+                return _instance.DescendOnce();
+            }
+
+            public IEnumerable<Our.IClass> Descend()
+            {
+                return _instance.Descend();
+            }
+
+            public void Accept(Our.Visitation.IVisitor visitor)
+            {
+                visitor.VisitSpecialItem(_instance);
+            }
+
+            public void Accept<TContext>(
+                Visitation.IVisitorWithContext<TContext> visitor,
+                TContext context
+            )
+            {
+                visitor.VisitSpecialItem(_instance, context);
+            }
+
+            public T Transform<T>(Visitation.ITransformer<T> transformer)
+            {
+                return transformer.TransformSpecialItem(_instance);
+            }
+
+            public T Transform<TContext, T>(
+                Visitation.ITransformerWithContext<TContext, T> transformer,
+                TContext context
+            )
+            {
+                return transformer.TransformSpecialItem(_instance, context);
+            }
+        }
+
+        public class EnhancedContainer<TEnhancement>
+            : Enhanced<TEnhancement>, Our.IContainer
+            where TEnhancement : class
+        {
+            private readonly Our.IContainer _instance;
+
+            public EnhancedContainer(
+                Our.IContainer instance,
+                TEnhancement enhancement
+            ) : base(enhancement)
+            {
+                _instance = instance;
+            }
+
+            public List<IItem> Items
+            {
+                get => _instance.Items;
+                set => _instance.Items = value;
+            }
+
+            public List<ISomeItem> SomeItems
+            {
+                get => _instance.SomeItems;
+                set => _instance.SomeItems = value;
+            }
+
+            public List<ISpecialItem>? SpecialItems
+            {
+                get => _instance.SpecialItems;
+                set => _instance.SpecialItems = value;
+            }
+
+            public IEnumerable<Our.ISpecialItem> OverSpecialItemsOrEmpty()
+            {
+                return _instance.OverSpecialItemsOrEmpty();
+            }
+
+            public long CountItems(
+                List<Our.IItem> items
+            )
+            {
+                return _instance.CountItems(
+                    items
+                );
+            }
+
+            public IEnumerable<Our.IClass> DescendOnce()
+            {
+                return _instance.DescendOnce();
+            }
+
+            public IEnumerable<Our.IClass> Descend()
+            {
+                return _instance.Descend();
+            }
+
+            public void Accept(Our.Visitation.IVisitor visitor)
+            {
+                visitor.VisitContainer(_instance);
+            }
+
+            public void Accept<TContext>(
+                Visitation.IVisitorWithContext<TContext> visitor,
+                TContext context
+            )
+            {
+                visitor.VisitContainer(_instance, context);
+            }
+
+            public T Transform<T>(Visitation.ITransformer<T> transformer)
+            {
+                return transformer.TransformContainer(_instance);
+            }
+
+            public T Transform<TContext, T>(
+                Visitation.ITransformerWithContext<TContext, T> transformer,
+                TContext context
+            )
+            {
+                return transformer.TransformContainer(_instance, context);
+            }
+        }
+
+        public class EnhancedWrapper<TEnhancement>
+            : Enhanced<TEnhancement>, Our.IWrapper
+            where TEnhancement : class
+        {
+            private readonly Our.IWrapper _instance;
+
+            public EnhancedWrapper(
+                Our.IWrapper instance,
+                TEnhancement enhancement
+            ) : base(enhancement)
+            {
+                _instance = instance;
+            }
+
+            public IContainer Container
+            {
+                get => _instance.Container;
+                set => _instance.Container = value;
+            }
+
+            public IEnumerable<Our.IClass> DescendOnce()
+            {
+                return _instance.DescendOnce();
+            }
+
+            public IEnumerable<Our.IClass> Descend()
+            {
+                return _instance.Descend();
+            }
+
+            public void Accept(Our.Visitation.IVisitor visitor)
+            {
+                visitor.VisitWrapper(_instance);
+            }
+
+            public void Accept<TContext>(
+                Visitation.IVisitorWithContext<TContext> visitor,
+                TContext context
+            )
+            {
+                visitor.VisitWrapper(_instance, context);
+            }
+
+            public T Transform<T>(Visitation.ITransformer<T> transformer)
+            {
+                return transformer.TransformWrapper(_instance);
+            }
+
+            public T Transform<TContext, T>(
+                Visitation.ITransformerWithContext<TContext, T> transformer,
+                TContext context
+            )
+            {
+                return transformer.TransformWrapper(_instance, context);
+            }
+        }
+
+        internal class Wrapper<TEnhancement>
+            : Our.Visitation.AbstractTransformer<Our.IClass>
+            where TEnhancement : class
+        {
+            private readonly System.Func<Our.IClass, TEnhancement?> _enhancementFactory;
+
+            internal Wrapper(
+                System.Func<Our.IClass, TEnhancement?> enhancementFactory
+            )
+            {
+                _enhancementFactory = enhancementFactory;
+            }
+
+            public override Our.IClass TransformSomeItem(
+                Our.ISomeItem that
+            )
+            {
+                if (that is Enhanced<TEnhancement>)
+                {
+                    throw new System.ArgumentException(
+                        $"The instance has been already enhanced: {that}"
+                    );
+                }
+
+                var enhancement = _enhancementFactory(that);
+                return (enhancement == null)
+                    ? that
+                    : new EnhancedSomeItem<TEnhancement>(
+                        that,
+                        enhancement
+                    );
+            }
+
+            public override Our.IClass TransformSpecialItem(
+                Our.ISpecialItem that
+            )
+            {
+                if (that is Enhanced<TEnhancement>)
+                {
+                    throw new System.ArgumentException(
+                        $"The instance has been already enhanced: {that}"
+                    );
+                }
+
+                var enhancement = _enhancementFactory(that);
+                return (enhancement == null)
+                    ? that
+                    : new EnhancedSpecialItem<TEnhancement>(
+                        that,
+                        enhancement
+                    );
+            }
+
+            public override Our.IClass TransformContainer(
+                Our.IContainer that
+            )
+            {
+                if (that is Enhanced<TEnhancement>)
+                {
+                    throw new System.ArgumentException(
+                        $"The instance has been already enhanced: {that}"
+                    );
+                }
+
+                that.Items = Wrap_ListOf_IItem(that.Items);
+
+                that.SomeItems = Wrap_ListOf_ISomeItem(that.SomeItems);
+
+                if (that.SpecialItems != null)
+                {
+                    that.SpecialItems = Wrap_ListOf_ISpecialItem(that.SpecialItems);
+                }
+
+                var enhancement = _enhancementFactory(that);
+                return (enhancement == null)
+                    ? that
+                    : new EnhancedContainer<TEnhancement>(
+                        that,
+                        enhancement
+                    );
+            }
+
+            public override Our.IClass TransformWrapper(
+                Our.IWrapper that
+            )
+            {
+                if (that is Enhanced<TEnhancement>)
+                {
+                    throw new System.ArgumentException(
+                        $"The instance has been already enhanced: {that}"
+                    );
+                }
+
+                that.Container = Wrap(that.Container);
+
+                var enhancement = _enhancementFactory(that);
+                return (enhancement == null)
+                    ? that
+                    : new EnhancedWrapper<TEnhancement>(
+                        that,
+                        enhancement
+                    );
+            }
+
+            /// <summary>
+            /// Wrap recursively <paramref name="that" /> and keep its static type.
+            /// </summary>
+            private T Wrap<T>(T that) where T : Our.IClass
+            {
+                var transformed = Transform(that);
+                return (transformed is T casted)
+                    ? casted
+                    : throw new System.InvalidOperationException(
+                        $"Expected the transformed value to be a {typeof(T).Name}, " +
+                        $"but got: {transformed}"
+                    );
+            }
+
+            /// <summary>
+            /// Wrap recursively the instances held by <paramref name="that" />.
+            /// </summary>
+            private List<Our.IItem> Wrap_ListOf_IItem(
+                List<Our.IItem> that)
+            {
+                var result = new List<Our.IItem>(that.Count);
+                foreach (var item in that)
+                {
+                    result.Add(Wrap(item));
+                }
+
+                return result;
+            }
+
+            /// <summary>
+            /// Wrap recursively the instances held by <paramref name="that" />.
+            /// </summary>
+            private List<Our.ISomeItem> Wrap_ListOf_ISomeItem(
+                List<Our.ISomeItem> that)
+            {
+                var result = new List<Our.ISomeItem>(that.Count);
+                foreach (var item in that)
+                {
+                    result.Add(Wrap(item));
+                }
+
+                return result;
+            }
+
+            /// <summary>
+            /// Wrap recursively the instances held by <paramref name="that" />.
+            /// </summary>
+            private List<Our.ISpecialItem> Wrap_ListOf_ISpecialItem(
+                List<Our.ISpecialItem> that)
+            {
+                var result = new List<Our.ISpecialItem>(that.Count);
+                foreach (var item in that)
+                {
+                    result.Add(Wrap(item));
+                }
+
+                return result;
+            }
+        }
+
+        /// <summary>
+        /// Unwrap enhancements from the wrapped instances.
+        /// </summary>
+        /// <typeparam name="TEnhancement">type of the enhancement</typeparam>
+        public class Unwrapper<TEnhancement> where TEnhancement : class
+        {
+            /// <summary>
+            /// Unwrap the given model instance.
+            /// </summary>
+            /// <param name="that">model instance to be unwrapped</param>
+            /// <returns>
+            /// Enhancement, or <c>null</c> if <paramref name="that" />
+            /// has not been wrapped yet.
+            /// </returns>
+            public TEnhancement? Unwrap(Our.IClass that)
+            {
+                // ReSharper disable once SuspiciousTypeConversion.Global
+                var enhanced = that as Enhanced<TEnhancement>;
+                return enhanced?._getEnhancement();
+            }
+
+            /// <summary>
+            /// Unwrap the given model instance.
+            /// </summary>
+            /// <param name="that">model instance to be unwrapped</param>
+            /// <returns>
+            /// Enhancement wrapped around <paramref name="that" />
+            /// </returns>
+            /// <exception cref="System.ArgumentException">
+            /// Thrown when <paramref name="that" /> has not been wrapped yet
+            /// </exception>
+            public TEnhancement MustUnwrap(Our.IClass that)
+            {
+                return Unwrap(that) ?? throw new System.ArgumentException(
+                    $"Expected the instance to have been wrapped, but it was not: {that}"
+                );
+            }
+        }  // public class Unwrapper
+
+        /// <summary>
+        /// Wrap and unwrap the instances of model classes with enhancement.
+        /// </summary>
+        /// <typeparam name="TEnhancement">type of the enhancement</typeparam>
+        public class Enhancer<TEnhancement>
+            : Unwrapper<TEnhancement>
+            where TEnhancement : class
+        {
+            private readonly Wrapper<TEnhancement> _wrapper;
+
+            /// <param name="enhancementFactory">
+            /// <para>how to enhance the instances.</para>
+            ///
+            /// <para>If it returns <c>null</c>, the instance will not be wrapped. However,
+            /// the wrapping will continue recursively.</para>
+            ///</param>
+            public Enhancer(
+                System.Func<Our.IClass, TEnhancement?> enhancementFactory
+            )
+            {
+                _wrapper = new Wrapper<TEnhancement>(enhancementFactory);
+            }
+
+            /// <summary>
+            /// Wrap the instance with an enhancement.
+            /// </summary>
+            /// <remarks>
+            /// Double wraps are not allowed to prevent runtime leakage.
+            ///
+            /// If you use references to the instance objects, you have to update them
+            /// after the wrapping, as the wrapping is recursive.
+            /// </remarks>
+            /// <param name="that">model instance to be wrapped</param>
+            /// <returns>
+            /// <paramref name="that" /> instance wrapped recursively with enhancements
+            /// </returns>
+            /// <exception cref="System.ArgumentException">
+            /// Thrown when <paramref name="that" /> has been already wrapped
+            /// </exception>
+            public Our.IClass Wrap(
+                Our.IClass that
+            )
+            {
+                var wrapped = _wrapper.Transform(that);
+                return (
+                    wrapped
+                ) ?? throw new System.InvalidOperationException(
+                    "Expected the wrapped instance to be an instance of IClass, " +
+                    $"but got: {wrapped}"
+                );
+            }
+        }  // public class Enhancer
+    }  // public static class Enhancing
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/jsonization.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/jsonization.cs
new file mode 100644
index 000000000..e7640ed64
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/jsonization.cs
@@ -0,0 +1,1287 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using CodeAnalysis = System.Diagnostics.CodeAnalysis;
+using Nodes = System.Text.Json.Nodes;
+
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide de/serialization of meta-model classes to/from JSON.
+    /// </summary>
+    /// <remarks>
+    /// We can not use one-pass deserialization for JSON since the object
+    /// properties do not have fixed order, and hence we can not read
+    /// <c>modelType</c> property ahead of the remaining properties.
+    /// </remarks>
+    public static class Jsonization
+    {
+        /// <summary>
+        /// Implement the deserialization of meta-model classes from JSON nodes.
+        /// </summary>
+        /// <remarks>
+        /// The implementation propagates an <see cref="Reporting.Error" /> instead of relying
+        /// on exceptions. Under the assumption that incorrect data is much less
+        /// frequent than correct data, this makes the deserialization more
+        /// efficient.
+        ///
+        /// However, we do not want to force the client to deal with
+        /// the <see cref="Reporting.Error" /> class as this is not intuitive. Therefore
+        /// we distinguish the implementation, realized in
+        /// <see cref="DeserializeImplementation" />, and the facade given in
+        /// <see cref="Deserialize" /> class.
+        ///
+        /// Every value is de-serialized through one and the same shape,
+        /// <c>Deserializer&lt;T&gt;</c>, so that the de-serialization of a list or of
+        /// a tuple can be composed out of the de-serialization of its items. A value
+        /// is returned as a plain <c>T</c>, meaningless unless the <c>error</c> is
+        /// null, since a <c>T?</c> can not be written down for an unconstrained
+        /// <c>T</c>.
+        /// </remarks>
+        internal static class DeserializeImplementation
+        {
+            /// <summary>
+            /// Describe <paramref name="node" /> in an error message.
+            /// </summary>
+            /// <remarks>
+            /// A JSON null is represented as a null node, so every "expected ..., but
+            /// got ..." message has to account for it. Doing so here, once, is what lets
+            /// a de-serializer take a nullable node and reject a null itself, instead of
+            /// every one of its callers checking for a null before calling it.
+            /// </remarks>
+            /// <param name="node">JSON node to be described</param>
+            private static string Describe(Nodes.JsonNode? node)
+            {
+                return (node == null)
+                    ? "a null"
+                    : node.GetType().ToString();
+            }
+
+            /// <summary>
+            /// Convert <paramref name="node" /> to a boolean.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static bool BoolFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonValue? value = node as Nodes.JsonValue;
+                if (value == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a boolean, but got {Describe(node)}");
+                    return default!;
+                }
+
+                bool ok = value.TryGetValue<bool>(out bool result);
+                if (!ok)
+                {
+                    error = new Reporting.Error(
+                        "Expected a boolean, but the conversion failed " +
+                        $"from {value.ToJsonString()}");
+                    return default!;
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Convert <paramref name="node" /> to a 64-bit long integer.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static long LongFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonValue? value = node as Nodes.JsonValue;
+                if (value == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a 64-bit long integer, but got {Describe(node)}");
+                    return default!;
+                }
+
+                bool ok = value.TryGetValue<long>(out long result);
+                if (!ok)
+                {
+                    error = new Reporting.Error(
+                        "Expected a 64-bit long integer, but the conversion failed " +
+                        $"from {value.ToJsonString()}");
+                    return default!;
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Convert <paramref name="node" /> to a 64-bit double-precision float.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static double DoubleFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonValue? value = node as Nodes.JsonValue;
+                if (value == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a 64-bit double-precision float, but got {Describe(node)}");
+                    return default!;
+                }
+
+                bool ok = value.TryGetValue<double>(out double result);
+                if (!ok)
+                {
+                    error = new Reporting.Error(
+                        "Expected a 64-bit double-precision float, but the conversion failed " +
+                        $"from {value.ToJsonString()}");
+                    return default!;
+                }
+                if (!System.Double.IsFinite(result))
+                {
+                    error = new Reporting.Error(
+                        $"Expected a finite number, but got {result}");
+                    return default!;
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Convert <paramref name="node" /> to a string.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static string StringFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonValue? value = node as Nodes.JsonValue;
+                if (value == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a string, but got {Describe(node)}");
+                    return default!;
+                }
+
+                bool ok = value.TryGetValue<string>(out string? result);
+                if (!ok)
+                {
+                    error = new Reporting.Error(
+                        "Expected a string, but the conversion failed " +
+                        $"from {value.ToJsonString()}");
+                    return default!;
+                }
+                if (result == null)
+                {
+                    error = new Reporting.Error(
+                        "Expected a string, but got a null");
+                    return default!;
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Convert <paramref name="node" /> to Base-64 encoded bytes.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static byte[] BytesFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonValue? value = node as Nodes.JsonValue;
+                if (value == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected Base-64 encoded bytes, but got {Describe(node)}");
+                    return default!;
+                }
+
+                bool ok = value.TryGetValue<string>(out string? text);
+                if (!ok)
+                {
+                    error = new Reporting.Error(
+                        "Expected Base-64 encoded bytes, but the conversion failed " +
+                        $"from {value.ToJsonString()}");
+                    return default!;
+                }
+                if (text == null)
+                {
+                    error = new Reporting.Error(
+                        "Expected Base-64 encoded bytes, but got a null");
+                    return default!;
+                }
+                try
+                {
+                    return System.Convert.FromBase64String(text);
+                }
+                catch (System.FormatException exception)
+                {
+                    error = new Reporting.Error(
+                        "Expected Base-64 encoded bytes, but the conversion failed " +
+                        $"because: {exception}");
+                    return default!;
+                }
+            }
+
+            /// <summary>
+            /// De-serialize a value from <paramref name="node" />.
+            /// </summary>
+            /// <remarks>
+            /// This is the one shape of every de-serialization, which is what lets
+            /// the de-serializations be composed: an <c>As*</c> combinator turns
+            /// the de-serializers of the items into the de-serializer of a list or
+            /// of a tuple of them, and the <c>...From</c> function of a primitive,
+            /// an enumeration, a class, an interface or a named union already is one.
+            ///
+            /// Return the value; on failure it is meaningless and
+            /// <paramref name="error" /> says why. A plain <c>T</c> rather than
+            /// a <c>T?</c>, so that one unconstrained delegate serves both the value
+            /// and the reference types: for a value type an unconstrained <c>T?</c>
+            /// erases to plain <c>T</c> rather than to <c>System.Nullable&lt;T&gt;</c>,
+            /// so a <c>T?</c> would have to be split into a <c>class</c>- and
+            /// a <c>struct</c>-constrained variant, and anything ranging over both --
+            /// such as the items of a tuple -- would then need an adapter between them.
+            ///
+            /// The <paramref name="node" /> is nullable since a JSON null is represented
+            /// as a null node. Each de-serializer rejects it with a message of its own,
+            /// so that the check is paid once per type instead of once per property.
+            ///
+            /// <typeparamref name="T" /> is covariant, so that the de-serializer of
+            /// a concrete class can be used as the de-serializer of an item of a list of
+            /// its interface.
+            /// </remarks>
+            /// <typeparam name="T">Type of the de-serialized value</typeparam>
+            private delegate T Deserializer<out T>(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error);
+
+            /// <summary>
+            /// De-serialize every item of a JSON array with
+            /// <paramref name="deserializeItem" />.
+            /// </summary>
+            /// <remarks>
+            /// This is shared by all the list-typed constructor arguments, regardless of
+            /// whether their items de-serialize into a reference or into a value type.
+            /// The result is cached in a <c>static readonly</c> field per item type
+            /// (see <c>Parse_ListOf_*</c>), so that composing it costs nothing at
+            /// the point of use.
+            /// </remarks>
+            /// <typeparam name="T">Type of a single array item</typeparam>
+            private static Deserializer<List<T>> AsArrayOf<T>(
+                Deserializer<T> deserializeItem)
+            {
+                return (
+                    Nodes.JsonNode? node,
+                    out Reporting.Error? error) =>
+                    {
+                        error = null;
+
+                        Nodes.JsonArray? array = node as Nodes.JsonArray;
+                        if (array == null)
+                        {
+                            error = new Reporting.Error(
+                                $"Expected a JsonArray, but got {Describe(node)}");
+                            return default!;
+                        }
+
+                        List<T> result = new List<T>(array.Count);
+
+                        int index = 0;
+                        foreach (Nodes.JsonNode? item in array)
+                        {
+                            T parsedItem = deserializeItem(item, out error);
+                            if (error != null)
+                            {
+                                error.PrependSegment(
+                                    new Reporting.IndexSegment(
+                                        index));
+                                return default!;
+                            }
+
+                            result.Add(parsedItem);
+
+                            index++;
+                        }
+
+                        return result;
+                    };
+            }
+
+            /// <summary>
+            /// Extract the <c>modelType</c> property of <paramref name="obj" />.
+            /// </summary>
+            /// <param name="obj">JSON object to be inspected</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            private static string ModelTypeFrom(
+                Nodes.JsonObject obj,
+                out Reporting.Error? error)
+            {
+                Nodes.JsonNode? modelTypeNode = obj["modelType"];
+                if (modelTypeNode == null)
+                {
+                    error = new Reporting.Error(
+                        "Expected a model type, but none is present");
+                    return default!;
+                }
+
+                string modelType = StringFrom(modelTypeNode, out error);
+                if (error != null)
+                {
+                    // NOTE (mristin):
+                    // A model type of a wrong type is reported at the property, as the type
+                    // errors of all the other properties are, and as in the other SDKs.
+                    error.PrependSegment(
+                        new Reporting.NameSegment("modelType"));
+                    return default!;
+                }
+                return modelType;
+            }
+
+            private static readonly Deserializer<List<IItem>> Parse_ListOf_IItem = (
+                AsArrayOf<IItem>(
+                    IItemFrom));
+
+            private static readonly Deserializer<List<ISomeItem>> Parse_ListOf_ISomeItem = (
+                AsArrayOf<ISomeItem>(
+                    ISomeItemFrom));
+
+            private static readonly Deserializer<List<ISpecialItem>> Parse_ListOf_ISpecialItem = (
+                AsArrayOf<ISpecialItem>(
+                    SpecialItemFrom));
+
+            /// <summary>
+            /// Deserialize an instance of IItem by dispatching
+            /// based on <c>modelType</c> property of the <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            public static Our.IItem IItemFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing IItem, but got {Describe(node)}");
+                    return default!;
+                }
+
+                string modelType = ModelTypeFrom(obj, out error);
+                if (error != null)
+                {
+                    return default!;
+                }
+
+                switch (modelType)
+                {
+                case "SomeItem":
+                    return SomeItemFrom(
+                        node, out error);
+                case "SpecialItem":
+                    return SpecialItemFrom(
+                        node, out error);
+                default:
+                    error = new Reporting.Error(
+                        $"Unexpected model type for IItem: {modelType}");
+                    return default!;
+                }
+            }  // public static Our.IItem IItemFrom
+
+            /// <summary>
+            /// Deserialize an instance of ISomeItem by dispatching
+            /// based on <c>modelType</c> property of the <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            public static Our.ISomeItem ISomeItemFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing ISomeItem, but got {Describe(node)}");
+                    return default!;
+                }
+
+                string modelType = ModelTypeFrom(obj, out error);
+                if (error != null)
+                {
+                    return default!;
+                }
+
+                switch (modelType)
+                {
+                case "SpecialItem":
+                    return SpecialItemFrom(
+                        node, out error);
+                case "SomeItem":
+                    return SomeItemFrom(
+                        node, out error);
+                default:
+                    error = new Reporting.Error(
+                        $"Unexpected model type for ISomeItem: {modelType}");
+                    return default!;
+                }
+            }  // public static Our.ISomeItem ISomeItemFrom
+
+            /// <summary>
+            /// Deserialize an instance of SomeItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static Our.SomeItem SomeItemFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing SomeItem, but got {Describe(node)}");
+                    return default!;
+                }
+
+                string? theName = null;
+                string? theNickname = null;
+
+                string? modelType = null;
+
+                foreach (var keyValue in obj)
+                {
+                    switch (keyValue.Key)
+                    {
+                        case "name":
+                            theName = StringFrom(
+                                keyValue.Value, out error);
+                            break;
+                        case "nickname":
+                            theNickname = StringFrom(
+                                keyValue.Value, out error);
+                            break;
+                        case "modelType":
+                            modelType = StringFrom(
+                                keyValue.Value, out error);
+                            if (error == null && modelType != "SomeItem")
+                            {
+                                // NOTE (mristin):
+                                // A wrong model type is reported at the instance, as an unknown one is,
+                                // and as in the other SDKs, so we return before the property is
+                                // prepended to the path.
+                                error = new Reporting.Error(
+                                    "Expected the model type 'SomeItem', " +
+                                    $"but got {modelType}");
+                                return default!;
+                            }
+                            break;
+                        default:
+                            error = new Reporting.Error(
+                                $"Unexpected property: {keyValue.Key}");
+                            return default!;
+                    }
+
+                    if (error != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(
+                                keyValue.Key));
+                        return default!;
+                    }
+                }
+
+                if (theName == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"name\" is missing");
+                    return default!;
+                }
+
+                if (modelType == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"modelType\" is missing");
+                    return default!;
+                }
+
+                return new Our.SomeItem(
+                    theName
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theNickname);
+            }  // internal static SomeItemFrom
+
+            /// <summary>
+            /// Deserialize an instance of SpecialItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static Our.SpecialItem SpecialItemFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing SpecialItem, but got {Describe(node)}");
+                    return default!;
+                }
+
+                string? theName = null;
+                long? theLevel = null;
+                string? theNickname = null;
+
+                string? modelType = null;
+
+                foreach (var keyValue in obj)
+                {
+                    switch (keyValue.Key)
+                    {
+                        case "name":
+                            theName = StringFrom(
+                                keyValue.Value, out error);
+                            break;
+                        case "level":
+                            theLevel = LongFrom(
+                                keyValue.Value, out error);
+                            break;
+                        case "nickname":
+                            theNickname = StringFrom(
+                                keyValue.Value, out error);
+                            break;
+                        case "modelType":
+                            modelType = StringFrom(
+                                keyValue.Value, out error);
+                            if (error == null && modelType != "SpecialItem")
+                            {
+                                // NOTE (mristin):
+                                // A wrong model type is reported at the instance, as an unknown one is,
+                                // and as in the other SDKs, so we return before the property is
+                                // prepended to the path.
+                                error = new Reporting.Error(
+                                    "Expected the model type 'SpecialItem', " +
+                                    $"but got {modelType}");
+                                return default!;
+                            }
+                            break;
+                        default:
+                            error = new Reporting.Error(
+                                $"Unexpected property: {keyValue.Key}");
+                            return default!;
+                    }
+
+                    if (error != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(
+                                keyValue.Key));
+                        return default!;
+                    }
+                }
+
+                if (theName == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"name\" is missing");
+                    return default!;
+                }
+
+                if (theLevel == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"level\" is missing");
+                    return default!;
+                }
+
+                if (modelType == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"modelType\" is missing");
+                    return default!;
+                }
+
+                return new Our.SpecialItem(
+                    theName
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theLevel
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theNickname);
+            }  // internal static SpecialItemFrom
+
+            /// <summary>
+            /// Deserialize an instance of Container from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static Our.Container ContainerFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing Container, but got {Describe(node)}");
+                    return default!;
+                }
+
+                List<IItem>? theItems = null;
+                List<ISomeItem>? theSomeItems = null;
+                List<ISpecialItem>? theSpecialItems = null;
+
+                foreach (var keyValue in obj)
+                {
+                    switch (keyValue.Key)
+                    {
+                        case "items":
+                            theItems = Parse_ListOf_IItem(
+                                keyValue.Value, out error);
+                            break;
+                        case "someItems":
+                            theSomeItems = Parse_ListOf_ISomeItem(
+                                keyValue.Value, out error);
+                            break;
+                        case "specialItems":
+                            theSpecialItems = Parse_ListOf_ISpecialItem(
+                                keyValue.Value, out error);
+                            break;
+                        default:
+                            error = new Reporting.Error(
+                                $"Unexpected property: {keyValue.Key}");
+                            return default!;
+                    }
+
+                    if (error != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(
+                                keyValue.Key));
+                        return default!;
+                    }
+                }
+
+                if (theItems == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"items\" is missing");
+                    return default!;
+                }
+
+                if (theSomeItems == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"someItems\" is missing");
+                    return default!;
+                }
+
+                return new Our.Container(
+                    theItems
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theSomeItems
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theSpecialItems);
+            }  // internal static ContainerFrom
+
+            /// <summary>
+            /// Deserialize an instance of Wrapper from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <param name="error">Error, if any, during the deserialization</param>
+            internal static Our.Wrapper WrapperFrom(
+                Nodes.JsonNode? node,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                Nodes.JsonObject? obj = node as Nodes.JsonObject;
+                if (obj == null)
+                {
+                    error = new Reporting.Error(
+                        $"Expected a JsonObject representing Wrapper, but got {Describe(node)}");
+                    return default!;
+                }
+
+                IContainer? theContainer = null;
+
+                foreach (var keyValue in obj)
+                {
+                    switch (keyValue.Key)
+                    {
+                        case "container":
+                            theContainer = ContainerFrom(
+                                keyValue.Value, out error);
+                            break;
+                        default:
+                            error = new Reporting.Error(
+                                $"Unexpected property: {keyValue.Key}");
+                            return default!;
+                    }
+
+                    if (error != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(
+                                keyValue.Key));
+                        return default!;
+                    }
+                }
+
+                if (theContainer == null)
+                {
+                    error = new Reporting.Error(
+                        "Required property \"container\" is missing");
+                    return default!;
+                }
+
+                return new Our.Wrapper(
+                    theContainer
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"));
+            }  // internal static WrapperFrom
+        }  // public static class DeserializeImplementation
+
+        /// <summary>
+        /// Represent a critical error during the deserialization.
+        /// </summary>
+        public class Exception : System.Exception
+        {
+            public readonly string Path;
+            public readonly string Cause;
+            public Exception(string path, string cause)
+                : base($"{cause} at: {path}")
+            {
+                Path = path;
+                Cause = cause;
+            }
+        }
+
+        /// <summary>
+        /// Represent a critical error during the serialization.
+        /// </summary>
+        public class SerializationException : System.Exception
+        {
+            public readonly string Path;
+            public readonly string Cause;
+            public SerializationException(string path, string cause)
+                : base($"{cause} at: {path}")
+            {
+                Path = path;
+                Cause = cause;
+            }
+        }
+
+        /// <summary>
+        /// Signal a failure of the serialization, carrying the path to the culprit.
+        /// </summary>
+        /// <remarks>
+        /// The path is built as the stack unwinds -- every container prepends the one
+        /// segment it knows, the property its name and the list the index of the item
+        /// -- which is why this can not be a <see cref="SerializationException" />
+        /// already: that one renders its message in its constructor, so its path has
+        /// to be complete by then. <see cref="Serialize.ToJsonObject" /> renders and
+        /// converts.
+        /// </remarks>
+        internal class SerializationFailure : System.Exception
+        {
+            public readonly Reporting.Error Error;
+            public SerializationFailure(Reporting.Error error)
+                : base(error.Cause)
+            {
+                Error = error;
+            }
+        }
+
+        /// <summary>
+        /// Deserialize instances of meta-model classes from JSON nodes.
+        /// </summary>
+        /// <example>
+        /// Here is an example how to parse an instance of IItem:
+        /// <code>
+        /// string someString = "... some JSON ...";
+        /// var node = System.Text.Json.Nodes.JsonNode.Parse(someString);
+        /// Our.IItem anInstance = Deserialize.IItemFrom(
+        ///     node);
+        /// </code>
+        /// </example>
+        public static class Deserialize
+        {
+            /// <summary>
+            /// Deserialize an instance of IItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of IItem.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            public static Our.IItem IItemFrom(
+                Nodes.JsonNode node)
+            {
+                Our.IItem result = DeserializeImplementation.IItemFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of ISomeItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of ISomeItem.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            public static Our.ISomeItem ISomeItemFrom(
+                Nodes.JsonNode node)
+            {
+                Our.ISomeItem result = DeserializeImplementation.ISomeItemFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of SomeItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of SomeItem.
+            /// </exception>
+            public static Our.SomeItem SomeItemFrom(
+                Nodes.JsonNode node)
+            {
+                Our.SomeItem result = DeserializeImplementation.SomeItemFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of SpecialItem from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of SpecialItem.
+            /// </exception>
+            public static Our.SpecialItem SpecialItemFrom(
+                Nodes.JsonNode node)
+            {
+                Our.SpecialItem result = DeserializeImplementation.SpecialItemFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of Container from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of Container.
+            /// </exception>
+            public static Our.Container ContainerFrom(
+                Nodes.JsonNode node)
+            {
+                Our.Container result = DeserializeImplementation.ContainerFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of Wrapper from <paramref name="node" />.
+            /// </summary>
+            /// <param name="node">JSON node to be parsed</param>
+            /// <exception cref="Jsonization.Exception">
+            /// Thrown when <paramref name="node" /> is not a valid JSON
+            /// representation of Wrapper.
+            /// </exception>
+            public static Our.Wrapper WrapperFrom(
+                Nodes.JsonNode node)
+            {
+                Our.Wrapper result = DeserializeImplementation.WrapperFrom(
+                    node,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    throw new Jsonization.Exception(
+                        Reporting.GenerateJsonPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+        }  // public static class Deserialize
+
+        internal class Transformer
+            : Visitation.AbstractTransformer<Nodes.JsonObject>
+        {
+            /// <summary>
+            /// Dispatch the serialization over the run-time type of an instance.
+            /// </summary>
+            /// <remarks>
+            /// The transformer carries no state, so a single instance serves the whole
+            /// program. No field initializer reads it, only
+            /// <see cref="TransformIClass" /> does, so it does not matter where among
+            /// the serializers it is initialized.
+            /// </remarks>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            private static readonly Transformer _instance = new Transformer();
+
+            /// <summary>
+            /// Serialize <paramref name="that" /> into a JSON object.
+            /// </summary>
+            /// <remarks>
+            /// Which JSON object that is, is decided by the run-time type of
+            /// <paramref name="that" />, so this one serializer serves every abstract
+            /// class and every concrete class with descendants, as well as the item of
+            /// a list or of a tuple of any of them.
+            /// </remarks>
+            internal static Nodes.JsonObject TransformIClass(Our.IClass that)
+            {
+                return _instance.Transform(that);
+            }
+
+            /// <summary>
+            /// Convert <paramref name="that" /> 64-bit long integer to a JSON value.
+            /// </summary>
+            /// <param name="that">value to be converted</param>
+            /// <exception name="SerializationFailure">
+            /// Thrown if <paramref name="that" /> lies outside the range where it can be
+            /// exactly represented as a 64-bit floating-point number, which is what
+            /// the JSON de-serializers of the other languages read a number into.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "UnusedMember.Local")]
+            private static Nodes.JsonValue ToJsonValue(long that)
+            {
+                if (that < -9007199254740991L || that > 9007199254740991L)
+                {
+                    throw new SerializationFailure(
+                        new Reporting.Error(
+                            "The integer can not be serialized to JSON as it is outside " +
+                            $"the range [-2^53 + 1, 2^53 - 1]: {that}"));
+                }
+                return Nodes.JsonValue.Create(that);
+            }
+
+            /// <summary>
+            /// Convert <paramref name="that" /> 64-bit floating-point number to a JSON
+            /// value.
+            /// </summary>
+            /// <param name="that">value to be converted</param>
+            /// <exception name="SerializationFailure">
+            /// Thrown if <paramref name="that" /> is not finite. JSON knows neither
+            /// an infinity nor a not-a-number, so we refuse them here instead of
+            /// leaving it to <c>System.Text.Json</c>, which throws much later -- when
+            /// the caller writes the document out -- and says nothing about where
+            /// the offending value sat.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "UnusedMember.Local")]
+            private static Nodes.JsonValue ToJsonValue(double that)
+            {
+                if (!System.Double.IsFinite(that))
+                {
+                    throw new SerializationFailure(
+                        new Reporting.Error(
+                            "JSON knows neither an infinity nor a not-a-number, so " +
+                            $"the value can not be serialized: {that}"));
+                }
+                return Nodes.JsonValue.Create(that);
+            }
+
+            /// <summary>
+            /// Serialize <paramref name="that" /> into a JSON value.
+            /// </summary>
+            /// <remarks>
+            /// This is the shape shared by every serialization step, so that the steps
+            /// can be composed. Unlike the XML side, no combinator is needed to frame
+            /// the value -- a JSON value stands on its own -- so the only composition
+            /// is over the items of a list or of a tuple.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value to be serialized</typeparam>
+            private delegate Nodes.JsonNode? Serializer<in T>(T that);
+
+            /// <summary>
+            /// Convert <paramref name="that" /> to a JSON value.
+            /// </summary>
+            private static Nodes.JsonValue ToJsonValue(string that)
+            {
+                return Nodes.JsonValue.Create(that)
+                    ?? throw new System.InvalidOperationException(
+                        "Unexpected null JSON value from a non-null string");
+            }
+
+            /// <summary>
+            /// Compose the serializer of a list whose items are serialized with
+            /// <paramref name="serializeItem" />.
+            /// </summary>
+            /// <remarks>
+            /// This is shared by all the list-typed properties. The composition is
+            /// performed once, when the field holding the result is initialized, so
+            /// serializing a list allocates nothing besides the JSON array itself.
+            ///
+            /// The parameter is a <c>List</c> rather than an <c>IEnumerable</c> so that
+            /// the iteration does not box the enumerator -- which is also the type that
+            /// every list-typed property actually has.
+            /// </remarks>
+            /// <typeparam name="T">Type of a single list item</typeparam>
+            private static Serializer<List<T>> SerializeList<T>(
+                Serializer<T> serializeItem)
+            {
+                return (that) =>
+                {
+                    var result = new Nodes.JsonArray();
+                    int i = 0;
+                    foreach (T item in that)
+                    {
+                        try
+                        {
+                            result.Add(serializeItem(item));
+                        }
+                        catch (SerializationFailure failure)
+                        {
+                            failure.Error.PrependSegment(
+                                new Reporting.IndexSegment(i));
+                            throw;
+                        }
+                        i++;
+                    }
+                    return result;
+                };
+            }
+
+            private static readonly Serializer<List<IItem>> Serialize_ListOf_IItem = (
+                SerializeList<IItem>(
+                    TransformIClass));
+
+            private static readonly Serializer<List<ISomeItem>> Serialize_ListOf_ISomeItem = (
+                SerializeList<ISomeItem>(
+                    TransformIClass));
+
+            private static readonly Serializer<List<ISpecialItem>> Serialize_ListOf_ISpecialItem = (
+                SerializeList<ISpecialItem>(
+                    TransformIClass));
+
+            private static readonly Serializer<string> Serialize_string = ToJsonValue;
+
+            private static readonly Serializer<long> Serialize_long = ToJsonValue;
+
+            private static readonly Serializer<Our.IClass> Serialize_IClass = TransformIClass;
+
+            /// <summary>
+            /// Set the property <paramref name="jsonName" /> of
+            /// <paramref name="result" /> to <paramref name="that" />, serialized by
+            /// <paramref name="serialize" />.
+            /// </summary>
+            /// <remarks>
+            /// <paramref name="propertyName" /> names the property on the path of
+            /// a failure. It is the C# property, and not the JSON one: a serialization
+            /// error is reported on an <em>instance</em>, which the caller holds, and
+            /// not on a document which has not been written yet.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value to serialize</typeparam>
+            private static void SetProperty<T>(
+                Nodes.JsonObject result,
+                string jsonName,
+                string propertyName,
+                T that,
+                Serializer<T> serialize)
+            {
+                try
+                {
+                    result[jsonName] = serialize(that);
+                }
+                catch (SerializationFailure failure)
+                {
+                    failure.Error.PrependSegment(
+                        new Reporting.NameSegment(propertyName));
+                    throw;
+                }
+            }
+
+            public override Nodes.JsonObject TransformSomeItem(
+                Our.ISomeItem that
+            )
+            {
+                var result = new Nodes.JsonObject();
+
+                SetProperty(result, "name", "Name", that.Name, Serialize_string);
+
+                if (that.Nickname != null)
+                {
+                    SetProperty(result, "nickname", "Nickname", that.Nickname, Serialize_string);
+                }
+
+                result["modelType"] = "SomeItem";
+
+                return result;
+            }
+
+            public override Nodes.JsonObject TransformSpecialItem(
+                Our.ISpecialItem that
+            )
+            {
+                var result = new Nodes.JsonObject();
+
+                SetProperty(result, "name", "Name", that.Name, Serialize_string);
+
+                if (that.Nickname != null)
+                {
+                    SetProperty(result, "nickname", "Nickname", that.Nickname, Serialize_string);
+                }
+
+                SetProperty(result, "level", "Level", that.Level, Serialize_long);
+
+                result["modelType"] = "SpecialItem";
+
+                return result;
+            }
+
+            public override Nodes.JsonObject TransformContainer(
+                Our.IContainer that
+            )
+            {
+                var result = new Nodes.JsonObject();
+
+                SetProperty(result, "items", "Items", that.Items, Serialize_ListOf_IItem);
+
+                SetProperty(
+                    result,
+                    "someItems",
+                    "SomeItems",
+                    that.SomeItems,
+                    Serialize_ListOf_ISomeItem);
+
+                if (that.SpecialItems != null)
+                {
+                    SetProperty(
+                        result,
+                        "specialItems",
+                        "SpecialItems",
+                        that.SpecialItems,
+                        Serialize_ListOf_ISpecialItem);
+                }
+
+                return result;
+            }
+
+            public override Nodes.JsonObject TransformWrapper(
+                Our.IWrapper that
+            )
+            {
+                var result = new Nodes.JsonObject();
+
+                SetProperty(result, "container", "Container", that.Container, Serialize_IClass);
+
+                return result;
+            }
+        }  // internal class Transformer
+
+        /// <summary>
+        /// Serialize instances of meta-model classes to JSON elements.
+        /// </summary>
+        /// <example>
+        /// Here is an example how to serialize an instance of IItem:
+        /// <code>
+        /// var anInstance = new Our.IItem(
+        ///     // ... some constructor arguments ...
+        /// );
+        /// System.Text.Json.Nodes.JsonObject element = (
+        ///     Serialize.ToJsonObject(
+        ///         anInstance));
+        /// </code>
+        /// </example>
+        public static class Serialize
+        {
+            /// <summary>
+            /// Serialize an instance of the meta-model into a JSON object.
+            /// </summary>
+            /// <exception cref="SerializationException">
+            /// Thrown when a value within <paramref name="that" /> instance can not be
+            /// represented in JSON
+            /// </exception>
+            public static Nodes.JsonObject ToJsonObject(Our.IClass that)
+            {
+                try
+                {
+                    return Transformer.TransformIClass(that);
+                }
+                catch (SerializationFailure failure)
+                {
+                    throw new SerializationException(
+                        Reporting.GenerateCSharpPath(failure.Error.PathSegments),
+                        failure.Error.Cause);
+                }
+            }
+        }  // public static class Serialize
+    }  // public static class Jsonization
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/reporting.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/reporting.cs
new file mode 100644
index 000000000..4c2c4a848
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/reporting.cs
@@ -0,0 +1,275 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using CodeAnalysis = System.Diagnostics.CodeAnalysis;
+
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide reporting for de/serialization and verification.
+    /// </summary>
+    public static class Reporting
+    {
+        /// <summary>
+        /// Capture a path segment of a value in a model.
+        /// </summary>
+        public abstract class Segment
+        {
+            // Intentionally empty.
+        }
+
+        public class NameSegment : Segment
+        {
+            public readonly string Name;
+            public NameSegment(string name)
+            {
+                Name = name;
+            }
+        }
+
+        public class IndexSegment : Segment
+        {
+            public readonly int Index;
+            public IndexSegment(int index)
+            {
+                Index = index;
+            }
+        }
+
+        /// <summary>
+        /// Capture a member of an open JSON-able object on a path to
+        /// the erroneous value.
+        /// </summary>
+        /// <remarks>
+        /// Unlike a <see cref="NameSegment" />, which names a property of one of
+        /// our classes, a key is known only at run time, and can be any string
+        /// at all.
+        /// </remarks>
+        public class KeySegment : Segment
+        {
+            public readonly string Key;
+            public KeySegment(string key)
+            {
+                Key = key;
+            }
+        }
+
+        /// <summary>
+        /// Escape the characters which a JSON string may not hold as they are.
+        /// </summary>
+        private static string EscapeForJsonString(
+            string text)
+        {
+            var builder = new System.Text.StringBuilder(text.Length);
+            foreach (char character in text)
+            {
+                switch (character)
+                {
+                    case '\\':
+                        builder.Append("\\\\");
+                        break;
+                    case '"':
+                        builder.Append("\\\"");
+                        break;
+                    case '\b':
+                        builder.Append("\\b");
+                        break;
+                    case '\f':
+                        builder.Append("\\f");
+                        break;
+                    case '\n':
+                        builder.Append("\\n");
+                        break;
+                    case '\r':
+                        builder.Append("\\r");
+                        break;
+                    case '\t':
+                        builder.Append("\\t");
+                        break;
+                    default:
+                        // NOTE (mristin):
+                        // The other control characters can not stand in a JSON string as they
+                        // are, so we write them as Unicode escapes, as JSON.stringify does.
+                        if (character < 0x20)
+                        {
+                            builder.Append($"\\u{(int)character:x4}");
+                        }
+                        else
+                        {
+                            builder.Append(character);
+                        }
+                        break;
+                }
+            }
+            return builder.ToString();
+        }
+
+        private static readonly System.Text.RegularExpressions.Regex VariableNameRe = (
+            new System.Text.RegularExpressions.Regex(
+                @"^[a-zA-Z_][a-zA-Z_0-9]*$"));
+
+        /// <summary>
+        /// Generate a JSON Path based on the path segments.
+        /// </summary>
+        /// <remarks>
+        /// See, for example, this page for more information on JSON path:
+        /// https://support.smartbear.com/alertsite/docs/monitors/api/endpoint/jsonpath.html
+        /// </remarks>
+        public static string GenerateJsonPath(
+            ICollection<Segment> segments)
+        {
+            var parts = new List<string>(segments.Count);
+            int i = 0;
+            foreach (var segment in segments)
+            {
+                string? part;
+                switch (segment)
+                {
+                    case NameSegment nameSegment:
+                        if (VariableNameRe.IsMatch(nameSegment.Name))
+                        {
+                            part = (i == 0) ? nameSegment.Name : $".{nameSegment.Name}";
+                        }
+                        else
+                        {
+                            part = (
+                                $"[\"{EscapeForJsonString(nameSegment.Name)}\"]");
+                        }
+                        break;
+                    case IndexSegment indexSegment:
+                        part = $"[{indexSegment.Index}]";
+                        break;
+                    case KeySegment keySegment:
+                        // A key is no name of a property of one of our classes, so it is
+                        // always bracketed, whatever it looks like.
+                        part = (
+                            $"[\"{EscapeForJsonString(keySegment.Key)}\"]");
+                        break;
+                    default:
+                        throw new System.InvalidOperationException(
+                            $"Unexpected segment type: {segment.GetType()}");
+                }
+                parts.Add(part);
+                i++;
+            }
+            return string.Join("", parts);
+        }
+
+        /// <summary>
+        /// Generate a C# access path based on the path segments.
+        /// </summary>
+        /// <remarks>
+        /// The name segments are expected to denote the names of the properties in
+        /// C#, not the JSON property names. This is the path to report where in
+        /// an *instance* something went wrong -- on the serialization, say, where
+        /// the caller holds the instance and not a document.
+        ///
+        /// A key and an index segment need no spelling of their own: a JSON-able
+        /// value is a <see cref="System.Text.Json.Nodes.JsonNode" />, which indexes
+        /// by both, so the path reads as a C# expression on the instance, *e.g.*,
+        /// <c>.SomeProperty["some key"][2]</c>.
+        /// </remarks>
+        public static string GenerateCSharpPath(
+            ICollection<Segment> segments)
+        {
+            // NOTE (mristin):
+            // We re-use the JSON path formatting as the implementation, but introduce
+            // a separate function to signal to the reader in which form the name
+            // segments are expected.
+            return GenerateJsonPath(segments);
+        }
+
+        /// <summary>
+        /// Escape special characters for XPath.
+        /// </summary>
+        private static string EscapeForXPath(
+            string text)
+        {
+            // Mind the order, as we need to replace '&' first.
+            //
+            // For some benchmarks, see:
+            // https://stackoverflow.com/questions/1321331/replace-multiple-string-elements-in-c-sharp
+            return (
+                text
+                    // Even though ampersand, less-then etc. can not occur in valid element names,
+                    // we escape them here for easier debugging and better bug reports.
+                    .Replace("&", "&amp;")
+                    .Replace("/", "&#47;")
+                    .Replace("<", "&lt;")
+                    .Replace(">", "&gt;")
+                    .Replace("\"", "&quot;")
+                    .Replace("'", "&apos;")
+            );
+        }
+
+        /// <summary>
+        /// Generate a relative XPath based on the path segments.
+        /// </summary>
+        /// <remarks>
+        /// This method leaves out the leading slash ('/'). This is helpful if
+        /// to embed the error report in a larger document with a prefix etc.
+        /// </remarks>
+        public static string GenerateRelativeXPath(
+            ICollection<Segment> segments)
+        {
+            var parts = new List<string>(segments.Count);
+            foreach (var segment in segments)
+            {
+                string? part;
+                switch (segment)
+                {
+                    case NameSegment nameSegment:
+                        part = EscapeForXPath(nameSegment.Name);
+                        break;
+                    case IndexSegment indexSegment:
+                        // XPath counts the elements starting at one, while our indices
+                        // start at zero.
+                        part = $"*[{indexSegment.Index + 1}]";
+                        break;
+                    case KeySegment keySegment:
+                        // A JSON-able object is written as an XML-RPC <struct>, which
+                        // holds the key of a member in a <name> child element, and not in
+                        // an attribute, so the XPath has to match on that child element.
+                        part = (
+                            $"member[name=\"{EscapeForXPath(keySegment.Key)}\"]");
+                        break;
+                    default:
+                        throw new System.InvalidOperationException(
+                            $"Unexpected segment type: {segment.GetType()}");
+                }
+                parts.Add(part);
+            }
+            return string.Join("/", parts);
+        }
+
+        /// <summary>
+        /// Represent an error during the deserialization or the verification.
+        /// </summary>
+        public class Error
+        {
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            internal readonly LinkedList<Segment> _pathSegments = new LinkedList<Segment>();
+            public readonly string Cause;
+            public ICollection<Segment> PathSegments => _pathSegments;
+            public Error(string cause)
+            {
+                Cause = cause;
+            }
+
+            public void PrependSegment(Segment segment)
+            {
+                _pathSegments.AddFirst(segment);
+            }
+        }
+    }  // public static class Reporting
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/stringification.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/stringification.cs
new file mode 100644
index 000000000..df7b4ecff
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/stringification.cs
@@ -0,0 +1,22 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using CodeAnalysis = System.Diagnostics.CodeAnalysis;
+
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    public static class Stringification
+    {
+
+    }  // public static class Stringification
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/types.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/types.cs
new file mode 100644
index 000000000..5585f7612
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/types.cs
@@ -0,0 +1,578 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using EnumMemberAttribute = System.Runtime.Serialization.EnumMemberAttribute;
+
+using System.Collections.Generic;  // can't alias
+using System.Linq;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Represent a general class of the meta-model.
+    /// </summary>
+    public interface IClass
+    {
+        /// <summary>
+        /// Iterate over all the class instances referenced from this instance
+        /// without further recursion.
+        /// </summary>
+        public IEnumerable<IClass> DescendOnce();
+
+        /// <summary>
+        /// Iterate recursively over all the class instances referenced from this instance.
+        /// </summary>
+        public IEnumerable<IClass> Descend();
+
+        /// <summary>
+        /// Accept the <paramref name="visitor" /> to visit this instance
+        /// for double dispatch.
+        /// </summary>
+        public void Accept(Visitation.IVisitor visitor);
+
+        /// <summary>
+        /// Accept the visitor to visit this instance for double dispatch
+        /// with the <paramref name="context" />.
+        /// </summary>
+        public void Accept<TContext>(
+            Visitation.IVisitorWithContext<TContext> visitor,
+            TContext context);
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to transform this instance
+        /// for double dispatch.
+        /// </summary>
+        public T Transform<T>(Visitation.ITransformer<T> transformer);
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to visit this instance
+        /// for double dispatch with the <paramref name="context" />.
+        /// </summary>
+        public T Transform<TContext, T>(
+            Visitation.ITransformerWithContext<TContext, T> transformer,
+            TContext context);
+    }
+
+    public interface IItem : IClass
+    {
+        public string Name { get; set; }
+
+        public string? Nickname { get; set; }
+    }
+
+    public interface ISomeItem : IItem
+    {
+        // Intentionally empty.
+    }
+
+    public class SomeItem : ISomeItem
+    {
+        public string Name { get; set; }
+
+        public string? Nickname { get; set; }
+
+        /// <summary>
+        /// Iterate over all the class instances referenced from this instance
+        /// without further recursion.
+        /// </summary>
+        public IEnumerable<IClass> DescendOnce()
+        {
+            // No descendable properties
+            yield break;
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances referenced from this instance.
+        /// </summary>
+        public IEnumerable<IClass> Descend()
+        {
+            // No descendable properties
+            yield break;
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="visitor" /> to visit this instance
+        /// for double dispatch.
+        /// </summary>
+        public void Accept(Visitation.IVisitor visitor)
+        {
+            visitor.VisitSomeItem(this);
+        }
+
+        /// <summary>
+        /// Accept the visitor to visit this instance for double dispatch
+        /// with the <paramref name="context" />.
+        /// </summary>
+        public void Accept<TContext>(
+            Visitation.IVisitorWithContext<TContext> visitor,
+            TContext context)
+        {
+            visitor.VisitSomeItem(this, context);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to transform this instance
+        /// for double dispatch.
+        /// </summary>
+        public T Transform<T>(Visitation.ITransformer<T> transformer)
+        {
+            return transformer.TransformSomeItem(this);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to visit this instance
+        /// for double dispatch with the <paramref name="context" />.
+        /// </summary>
+        public T Transform<TContext, T>(
+            Visitation.ITransformerWithContext<TContext, T> transformer,
+            TContext context)
+        {
+            return transformer.TransformSomeItem(this, context);
+        }
+
+        public SomeItem(
+            string name,
+            string? nickname = null)
+        {
+            Name = name;
+            Nickname = nickname;
+        }
+    }
+
+    public interface ISpecialItem : ISomeItem
+    {
+        public long Level { get; set; }
+    }
+
+    public class SpecialItem : ISpecialItem
+    {
+        public string Name { get; set; }
+
+        public string? Nickname { get; set; }
+
+        public long Level { get; set; }
+
+        /// <summary>
+        /// Iterate over all the class instances referenced from this instance
+        /// without further recursion.
+        /// </summary>
+        public IEnumerable<IClass> DescendOnce()
+        {
+            // No descendable properties
+            yield break;
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances referenced from this instance.
+        /// </summary>
+        public IEnumerable<IClass> Descend()
+        {
+            // No descendable properties
+            yield break;
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="visitor" /> to visit this instance
+        /// for double dispatch.
+        /// </summary>
+        public void Accept(Visitation.IVisitor visitor)
+        {
+            visitor.VisitSpecialItem(this);
+        }
+
+        /// <summary>
+        /// Accept the visitor to visit this instance for double dispatch
+        /// with the <paramref name="context" />.
+        /// </summary>
+        public void Accept<TContext>(
+            Visitation.IVisitorWithContext<TContext> visitor,
+            TContext context)
+        {
+            visitor.VisitSpecialItem(this, context);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to transform this instance
+        /// for double dispatch.
+        /// </summary>
+        public T Transform<T>(Visitation.ITransformer<T> transformer)
+        {
+            return transformer.TransformSpecialItem(this);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to visit this instance
+        /// for double dispatch with the <paramref name="context" />.
+        /// </summary>
+        public T Transform<TContext, T>(
+            Visitation.ITransformerWithContext<TContext, T> transformer,
+            TContext context)
+        {
+            return transformer.TransformSpecialItem(this, context);
+        }
+
+        public SpecialItem(
+            string name,
+            long level,
+            string? nickname = null)
+        {
+            Name = name;
+            Nickname = nickname;
+            Level = level;
+        }
+    }
+
+    public interface IContainer : IClass
+    {
+        public List<IItem> Items { get; set; }
+
+        public List<ISomeItem> SomeItems { get; set; }
+
+        public List<ISpecialItem>? SpecialItems { get; set; }
+
+        /// <summary>
+        /// Count the <paramref name="items" />.
+        /// </summary>
+        /// <remarks>
+        /// The arguments of the methods are never generic, so only the sequences of
+        /// <see cref="Our.IItem" /> can be passed to it, but not the sequences of
+        /// the descendants.
+        /// </remarks>
+        public long CountItems(List<IItem> items);
+
+        /// <summary>
+        /// Iterate over SpecialItems, if set, and otherwise return an empty enumerable.
+        /// </summary>
+        public IEnumerable<ISpecialItem> OverSpecialItemsOrEmpty();
+    }
+
+    public class Container : IContainer
+    {
+        public List<IItem> Items { get; set; }
+
+        public List<ISomeItem> SomeItems { get; set; }
+
+        public List<ISpecialItem>? SpecialItems { get; set; }
+
+        /// <summary>
+        /// Iterate over SpecialItems, if set, and otherwise return an empty enumerable.
+        /// </summary>
+        public IEnumerable<ISpecialItem> OverSpecialItemsOrEmpty()
+        {
+            return SpecialItems
+                ?? System.Linq.Enumerable.Empty<ISpecialItem>();
+        }
+
+        /// <summary>
+        /// Count the <paramref name="items" />.
+        /// </summary>
+        /// <remarks>
+        /// The arguments of the methods are never generic, so only the sequences of
+        /// <see cref="Our.IItem" /> can be passed to it, but not the sequences of
+        /// the descendants.
+        /// </remarks>
+        public long CountItems(
+            List<IItem> items
+        )
+        {
+            return items.Count;
+        }
+
+        /// <summary>
+        /// Iterate over all the class instances referenced from this instance
+        /// without further recursion.
+        /// </summary>
+        public IEnumerable<IClass> DescendOnce()
+        {
+            foreach (var anItem in Descent.DescendOnce_ListOf_IItem(Items))
+            {
+                yield return anItem;
+            }
+
+            foreach (
+                var anItem in Descent.DescendOnce_ListOf_ISomeItem(
+                    SomeItems))
+            {
+                yield return anItem;
+            }
+
+            if (SpecialItems != null)
+            {
+                foreach (
+                    var anItem in Descent.DescendOnce_ListOf_ISpecialItem(
+                        SpecialItems))
+                {
+                    yield return anItem;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances referenced from this instance.
+        /// </summary>
+        public IEnumerable<IClass> Descend()
+        {
+            foreach (var anItem in Descent.Descend_ListOf_IItem(Items))
+            {
+                yield return anItem;
+            }
+
+            foreach (var anItem in Descent.Descend_ListOf_ISomeItem(SomeItems))
+            {
+                yield return anItem;
+            }
+
+            if (SpecialItems != null)
+            {
+                foreach (
+                    var anItem in Descent.Descend_ListOf_ISpecialItem(
+                        SpecialItems))
+                {
+                    yield return anItem;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="visitor" /> to visit this instance
+        /// for double dispatch.
+        /// </summary>
+        public void Accept(Visitation.IVisitor visitor)
+        {
+            visitor.VisitContainer(this);
+        }
+
+        /// <summary>
+        /// Accept the visitor to visit this instance for double dispatch
+        /// with the <paramref name="context" />.
+        /// </summary>
+        public void Accept<TContext>(
+            Visitation.IVisitorWithContext<TContext> visitor,
+            TContext context)
+        {
+            visitor.VisitContainer(this, context);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to transform this instance
+        /// for double dispatch.
+        /// </summary>
+        public T Transform<T>(Visitation.ITransformer<T> transformer)
+        {
+            return transformer.TransformContainer(this);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to visit this instance
+        /// for double dispatch with the <paramref name="context" />.
+        /// </summary>
+        public T Transform<TContext, T>(
+            Visitation.ITransformerWithContext<TContext, T> transformer,
+            TContext context)
+        {
+            return transformer.TransformContainer(this, context);
+        }
+
+        public Container(
+            List<IItem> items,
+            List<ISomeItem> someItems,
+            List<ISpecialItem>? specialItems = null)
+        {
+            Items = items;
+            SomeItems = someItems;
+            SpecialItems = specialItems;
+        }
+    }
+
+    public interface IWrapper : IClass
+    {
+        public IContainer Container { get; set; }
+    }
+
+    public class Wrapper : IWrapper
+    {
+        public IContainer Container { get; set; }
+
+        /// <summary>
+        /// Iterate over all the class instances referenced from this instance
+        /// without further recursion.
+        /// </summary>
+        public IEnumerable<IClass> DescendOnce()
+        {
+            yield return Container;
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances referenced from this instance.
+        /// </summary>
+        public IEnumerable<IClass> Descend()
+        {
+            yield return Container;
+
+            // Recurse
+            foreach (var anItem in Container.Descend())
+            {
+                yield return anItem;
+            }
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="visitor" /> to visit this instance
+        /// for double dispatch.
+        /// </summary>
+        public void Accept(Visitation.IVisitor visitor)
+        {
+            visitor.VisitWrapper(this);
+        }
+
+        /// <summary>
+        /// Accept the visitor to visit this instance for double dispatch
+        /// with the <paramref name="context" />.
+        /// </summary>
+        public void Accept<TContext>(
+            Visitation.IVisitorWithContext<TContext> visitor,
+            TContext context)
+        {
+            visitor.VisitWrapper(this, context);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to transform this instance
+        /// for double dispatch.
+        /// </summary>
+        public T Transform<T>(Visitation.ITransformer<T> transformer)
+        {
+            return transformer.TransformWrapper(this);
+        }
+
+        /// <summary>
+        /// Accept the <paramref name="transformer" /> to visit this instance
+        /// for double dispatch with the <paramref name="context" />.
+        /// </summary>
+        public T Transform<TContext, T>(
+            Visitation.ITransformerWithContext<TContext, T> transformer,
+            TContext context)
+        {
+            return transformer.TransformWrapper(this, context);
+        }
+
+        public Wrapper(IContainer container)
+        {
+            Container = container;
+        }
+    }
+
+    /// <summary>
+    /// Descend into the containers which hold class instances.
+    /// </summary>
+    /// <remarks>
+    /// Each method descends only one level, and calls the method of the items
+    /// by name, so that the descent is composed of plain functions to any depth.
+    /// </remarks>
+    internal static class Descent
+    {
+        /// <summary>
+        /// Iterate recursively over all the class instances held by
+        /// <paramref name="that" />.
+        /// </summary>
+        internal static IEnumerable<IClass> Descend_ListOf_IItem(
+            List<IItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+
+                // Recurse
+                foreach (var anItem in item.Descend())
+                {
+                    yield return anItem;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Iterate over the class instances held by <paramref name="that" />
+        /// without further recursion.
+        /// </summary>
+        internal static IEnumerable<IClass> DescendOnce_ListOf_IItem(
+            List<IItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+            }
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances held by
+        /// <paramref name="that" />.
+        /// </summary>
+        internal static IEnumerable<IClass> Descend_ListOf_ISomeItem(
+            List<ISomeItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+
+                // Recurse
+                foreach (var anItem in item.Descend())
+                {
+                    yield return anItem;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Iterate over the class instances held by <paramref name="that" />
+        /// without further recursion.
+        /// </summary>
+        internal static IEnumerable<IClass> DescendOnce_ListOf_ISomeItem(
+            List<ISomeItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+            }
+        }
+
+        /// <summary>
+        /// Iterate recursively over all the class instances held by
+        /// <paramref name="that" />.
+        /// </summary>
+        internal static IEnumerable<IClass> Descend_ListOf_ISpecialItem(
+            List<ISpecialItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+
+                // Recurse
+                foreach (var anItem in item.Descend())
+                {
+                    yield return anItem;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Iterate over the class instances held by <paramref name="that" />
+        /// without further recursion.
+        /// </summary>
+        internal static IEnumerable<IClass> DescendOnce_ListOf_ISpecialItem(
+            List<ISpecialItem> that)
+        {
+            foreach (var item in that)
+            {
+                yield return item;
+            }
+        }
+    }  // internal static class Descent
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/verification.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/verification.cs
new file mode 100644
index 000000000..ab19d73b6
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/verification.cs
@@ -0,0 +1,725 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using CodeAnalysis = System.Diagnostics.CodeAnalysis;
+using Regex = System.Text.RegularExpressions.Regex;
+
+using System.Collections.Generic;  // can't alias
+using System.Linq;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Verify that the instances of the meta-model satisfy the invariants.
+    /// </summary>
+    /// <example>
+    /// Here is an example how to verify an instance of IItem:
+    /// <code>
+    /// var anInstance = new Our.IItem(
+    ///     // ... some constructor arguments ...
+    /// );
+    /// foreach (var error in Verification.Verify(anInstance))
+    /// {
+    ///     System.Console.Writeln(
+    ///         $"{error.Cause} at: " +
+    ///         Reporting.GenerateJsonPath(error.PathSegments));
+    /// }
+    /// </code>
+    /// </example>
+    public static class Verification
+    {
+        /// <summary>
+        /// Check that the names of the <paramref name="items" /> are unique.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The <paramref name="items" /> are a generic sequence, so the sequences of
+        /// the descendants of <see cref="Our.IItem" /> can be passed without a copy.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool NamesAreUnique(
+            IReadOnlyList<IItem> items
+        )
+        {
+            HashSet<string> nameSet = new HashSet<string>();
+            foreach (var item in items)
+            {
+                if (nameSet.Contains(item.Name))
+                {
+                    return false;
+                }
+                nameSet.Add(item.Name);
+            }
+            return true;
+        }  // public static bool NamesAreUnique
+
+        /// <summary>
+        /// Iterate over a generic sequence in a generator.
+        /// </summary>
+        /// <remarks>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </remarks>
+        public static bool NamesAreNonEmpty(
+            IReadOnlyList<IItem> items
+        )
+        {
+            return items.All(
+                item => Common.StringHelpers.Len(item.Name) > 0);
+        }  // public static bool NamesAreNonEmpty
+
+        /// <summary>
+        /// Narrow the items of a generic sequence in a generator.
+        /// </summary>
+        /// <remarks>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </remarks>
+        public static bool SomeSpecialItemHasLevel(
+            IReadOnlyList<IItem> items
+        )
+        {
+            return items.Any(
+                item => item is Our.ISpecialItem
+                    && ((Our.ISpecialItem)item).Level > 0);
+        }  // public static bool SomeSpecialItemHasLevel
+
+        /// <summary>
+        /// Index a generic sequence, and narrow the item.
+        /// </summary>
+        /// <remarks>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </remarks>
+        public static bool FirstIsSpecial(
+            IReadOnlyList<IItem> items
+        )
+        {
+            if (items.Count == 0)
+            {
+                return false;
+            }
+            var first = items[0];
+            if (first is Our.ISpecialItem)
+            {
+                return ((Our.ISpecialItem)first).Level > 0;
+            }
+            return false;
+        }  // public static bool FirstIsSpecial
+
+        /// <summary>
+        /// Check that the nicknames of the <paramref name="items" /> are unique, if specified.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This mirrors the body of <c>ID_shorts_are_unique</c> in aas-core-meta V3.2:
+        /// a local variable takes an optional property of an item of a generic sequence,
+        /// and the loop continues if it is None.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool NicknamesAreUnique(
+            IReadOnlyList<IItem> items
+        )
+        {
+            HashSet<string> nicknameSet = new HashSet<string>();
+            foreach (var item in items)
+            {
+                var nickname = item.Nickname;
+                if (nickname == null)
+                {
+                    continue;
+                }
+                if (nicknameSet.Contains(nickname))
+                {
+                    return false;
+                }
+                nicknameSet.Add(nickname);
+            }
+            return true;
+        }  // public static bool NicknamesAreUnique
+
+        /// <summary>
+        /// Narrow the loop variable over a generic sequence in a for-loop.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The loop variable is of the type parameter in Go, so the down-cast needs to
+        /// go through <c>any(...)</c>, and of the template parameter in C++.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool LevelsOfSpecialItemsArePositive(
+            IReadOnlyList<IItem> items
+        )
+        {
+            foreach (var item in items)
+            {
+                if (item is Our.ISpecialItem)
+                {
+                    if (((Our.ISpecialItem)item).Level <= 0)
+                    {
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }  // public static bool LevelsOfSpecialItemsArePositive
+
+        /// <summary>
+        /// Narrow an immutable local variable which holds an item of a generic sequence.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// In contrast to <see cref="Our.Verification.FirstIsSpecial" />, the local variable is annotated, so
+        /// it is of the parent class instead of the type parameter. Hence, Go down-casts
+        /// it without <c>any(...)</c>, and C++ binds the item to a constant reference to
+        /// the shared pointer of the parent class.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool LastIsSpecial(
+            IReadOnlyList<IItem> items
+        )
+        {
+            if (items.Count == 0)
+            {
+                return false;
+            }
+            Our.IItem last = items[items.Count - 1];
+            if (last is Our.ISpecialItem)
+            {
+                return ((Our.ISpecialItem)last).Level > 0;
+            }
+            return false;
+        }  // public static bool LastIsSpecial
+
+        /// <summary>
+        /// Mix two generic sequences with an argument which is not generic.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The names must differ, except for the <paramref name="sharedName" />, which may repeat.
+        /// </para>
+        /// <para>
+        /// Go declares two type parameters, and C++ two template parameters. The nested
+        /// generators iterate over two different generic sequences, so their variables
+        /// are of two different type parameters.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// <para>
+        /// The argument otherItems is declared as the covariant IReadOnlyList&lt;ISomeItem&gt; instead of the invariant List&lt;ISomeItem&gt; so that the lists of the descendants of ISomeItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool NamesAreDisjoint(
+            IReadOnlyList<IItem> items,
+            IReadOnlyList<ISomeItem> otherItems,
+            string sharedName
+        )
+        {
+            return items.All(
+                item => otherItems.All(
+                        otherItem => item.Name != otherItem.Name
+                            || item.Name == sharedName));
+        }  // public static bool NamesAreDisjoint
+
+        /// <summary>
+        /// Use the immutable aliases of the generic sequences.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// An immutable alias of the very same type shares the type annotation of
+        /// the aliased generic sequence, so it is a generic sequence itself. Go declares
+        /// the alias with the type parameter, C++ with the template parameter, while C#
+        /// and Java infer its type with <c>var</c>. The <c>alias_of_alias</c> aliases an alias,
+        /// and the <c>optional_alias</c> aliases an optional generic sequence.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// <para>
+        /// The argument optionalItems is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool AliasedNamesAreUnique(
+            IReadOnlyList<IItem> items,
+            IReadOnlyList<IItem>? optionalItems
+        )
+        {
+            var alias = items;
+            var aliasOfAlias = alias;
+            var optionalAlias = optionalItems;
+            foreach (var item in alias)
+            {
+                if (item is Our.ISpecialItem)
+                {
+                    if (((Our.ISpecialItem)item).Level <= 0)
+                    {
+                        return false;
+                    }
+                }
+            }
+            return (
+                aliasOfAlias.All(
+                    item => Common.StringHelpers.Len(item.Name) > 0)
+            )
+            && Verification.NamesAreUnique(aliasOfAlias)
+            && Verification.OptionalNamesAreUnique(optionalAlias)
+            && (
+                (optionalAlias == null)
+                || Verification.NamesAreUnique(optionalAlias)
+            );
+        }  // public static bool AliasedNamesAreUnique
+
+        /// <summary>
+        /// Look up an instance of a descendant in a generic sequence.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Go compares the instances as <c>any</c>'s, as the items are of the type parameter,
+        /// and C++ converts the member to the shared pointer of <see cref="Our.IItem" /> so that
+        /// the raw pointers are comparable for any template parameter.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool ContainsSomeItem(
+            ISomeItem someItem,
+            IReadOnlyList<IItem> items
+        )
+        {
+            return items.Contains(someItem);
+        }  // public static bool ContainsSomeItem
+
+        /// <summary>
+        /// Look up the items of a generic sequence in another generic sequence.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The member and the items are of two different type parameters.
+        /// </para>
+        /// <para>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </para>
+        /// <para>
+        /// The argument otherItems is declared as the covariant IReadOnlyList&lt;ISomeItem&gt; instead of the invariant List&lt;ISomeItem&gt; so that the lists of the descendants of ISomeItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool ItemsOverlap(
+            IReadOnlyList<IItem> items,
+            IReadOnlyList<ISomeItem> otherItems
+        )
+        {
+            return otherItems.Any(
+                otherItem => items.Contains(otherItem));
+        }  // public static bool ItemsOverlap
+
+        /// <summary>
+        /// Look up an instance in a sequence which is not generic.
+        /// </summary>
+        /// <remarks>
+        /// The <see cref="Our.SpecialItem" /> has no descendants, so the <paramref name="items" /> are not
+        /// a generic sequence, but Go still compares the instances as <c>any</c>'s.
+        /// </remarks>
+        public static bool ContainsSpecialItem(
+            ISpecialItem specialItem,
+            List<ISpecialItem> items
+        )
+        {
+            return items.Contains(specialItem);
+        }  // public static bool ContainsSpecialItem
+
+        /// <summary>
+        /// Pass the local variables on to generic sequences.
+        /// </summary>
+        /// <remarks>
+        /// The <c>some_items</c> is a read-only alias without an annotation, while
+        /// the <c>all_some_items</c> is an immutable local variable declared with
+        /// <c>Final[...]</c>. Both hold the sequences of <see cref="Our.SomeItem" />, and are passed
+        /// on to the generic sequences of <see cref="Our.IItem" />, required as well as optional.
+        /// </remarks>
+        public static bool ContainerNamesAreUnique(
+            IContainer container
+        )
+        {
+            var someItems = container.SomeItems;
+            List<Our.ISomeItem> allSomeItems = container.SomeItems;
+            return Verification.NamesAreUnique(someItems)
+            && Verification.NamesAreUnique(allSomeItems)
+            && Verification.OptionalNamesAreUnique(allSomeItems);
+        }  // public static bool ContainerNamesAreUnique
+
+        /// <summary>
+        /// Pass an optional generic sequence on to a generic sequence.
+        /// </summary>
+        /// <remarks>
+        /// The argument items is declared as the covariant IReadOnlyList&lt;IItem&gt; instead of the invariant List&lt;IItem&gt; so that the lists of the descendants of IItem can be passed without a copy.
+        /// </remarks>
+        public static bool OptionalNamesAreUnique(
+            IReadOnlyList<IItem>? items
+        )
+        {
+            return (items == null)
+            || Verification.NamesAreUnique(items);
+        }  // public static bool OptionalNamesAreUnique
+
+        /// <summary>
+        /// Pass the generic sequences of the descendants on.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The <paramref name="someItems" /> are passed on as a required and as an optional
+        /// sequence of the parent class, while the <paramref name="specialItems" /> are passed on
+        /// as an optional sequence and, once narrowed, as a required sequence of the parent
+        /// class of the parent class.
+        /// </para>
+        /// <para>
+        /// The argument someItems is declared as the covariant IReadOnlyList&lt;ISomeItem&gt; instead of the invariant List&lt;ISomeItem&gt; so that the lists of the descendants of ISomeItem can be passed without a copy.
+        /// </para>
+        /// </remarks>
+        public static bool SomeNamesAreUnique(
+            IReadOnlyList<ISomeItem> someItems,
+            List<ISpecialItem>? specialItems
+        )
+        {
+            return Verification.NamesAreUnique(someItems)
+            && Verification.OptionalNamesAreUnique(someItems)
+            && Verification.OptionalNamesAreUnique(specialItems)
+            && Verification.OptionalNamesAreUnique(null)
+            && (
+                (specialItems == null)
+                || Verification.NamesAreUnique(specialItems)
+            );
+        }  // public static bool SomeNamesAreUnique
+
+        /// <summary>
+        /// Check that the levels are positive.
+        /// </summary>
+        /// <remarks>
+        /// The <see cref="Our.SpecialItem" /> has no descendants, so the <paramref name="items" /> are not
+        /// a generic sequence.
+        /// </remarks>
+        public static bool LevelsArePositive(
+            List<ISpecialItem> items
+        )
+        {
+            return items.All(
+                item => item.Level > 0);
+        }  // public static bool LevelsArePositive
+
+        /// <summary>
+        /// Hash allowed enum values for efficient validation of enums.
+        /// </summary>
+        internal static class EnumValueSet
+        {
+
+        }  // internal static class EnumValueSet
+
+        [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+        private static readonly Verification.Transformer _transformer = (
+            new Verification.Transformer());
+
+        private class Transformer
+            : Visitation.AbstractTransformer<IEnumerable<Reporting.Error>>
+        {
+            [CodeAnalysis.SuppressMessage("ReSharper", "NegativeEqualityExpression")]
+            public override IEnumerable<Reporting.Error> TransformSomeItem(
+                Our.ISomeItem that
+            )
+            {
+                // No verification has been defined for SomeItem.
+                yield break;
+            }
+
+            [CodeAnalysis.SuppressMessage("ReSharper", "NegativeEqualityExpression")]
+            public override IEnumerable<Reporting.Error> TransformSpecialItem(
+                Our.ISpecialItem that
+            )
+            {
+                // No verification has been defined for SpecialItem.
+                yield break;
+            }
+
+            [CodeAnalysis.SuppressMessage("ReSharper", "NegativeEqualityExpression")]
+            public override IEnumerable<Reporting.Error> TransformContainer(
+                Our.IContainer that
+            )
+            {
+                if (!(
+                    !(that.SpecialItems != null)
+                    || (
+                        that.SpecialItems.All(
+                            specialItem => Verification.ContainsSpecialItem(specialItem, that.SpecialItems))
+                    )))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Each special item must be among the special items.");
+                }
+
+                if (!(
+                    that.SomeItems.Count == 0
+                    || Verification.ItemsOverlap(that.Items, that.SomeItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "If there are some items, they must overlap with the items.");
+                }
+
+                if (!(
+                    that.SomeItems.All(
+                        someItem => Verification.ContainsSomeItem(someItem, that.Items))))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Some items must be among the items.");
+                }
+
+                if (!(
+                    Verification.AliasedNamesAreUnique(that.SomeItems, that.SpecialItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of some items and of special items must be unique " +
+                        "through aliases.");
+                }
+
+                if (!(
+                    Verification.NamesAreDisjoint(that.Items, that.SomeItems, "x")))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of the items and of some items must be disjoint.");
+                }
+
+                if (!(
+                    !Verification.SomeSpecialItemHasLevel(that.Items)
+                    || Verification.LastIsSpecial(that.Items)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "If there is a special item with level, the last item must " +
+                        "be special.");
+                }
+
+                if (!(
+                    Verification.LevelsOfSpecialItemsArePositive(that.Items)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Levels of the special items among the items must be " +
+                        "positive.");
+                }
+
+                if (!Verification.NicknamesAreUnique(that.SomeItems))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Nicknames of some items must be unique.");
+                }
+
+                if (!(that.CountItems(that.Items) == that.Items.Count))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Count of the items must match the number of the items.");
+                }
+
+                if (!(
+                    Verification.OptionalNamesAreUnique(that.SpecialItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of the special items must be unique.");
+                }
+
+                if (!(
+                    !(that.SpecialItems != null)
+                    || Verification.FirstIsSpecial(that.SpecialItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "The first special item must be special.");
+                }
+
+                if (!(
+                    !(that.SpecialItems != null)
+                    || Verification.LevelsArePositive(that.SpecialItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Levels of the special items must be positive.");
+                }
+
+                if (!(
+                    !Verification.SomeSpecialItemHasLevel(that.Items)
+                    || Verification.FirstIsSpecial(that.Items)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "If there is a special item with level, the first item must " +
+                        "be special.");
+                }
+
+                if (!Verification.NamesAreNonEmpty(that.SomeItems))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of some items must be non-empty.");
+                }
+
+                if (!(
+                    Verification.SomeNamesAreUnique(that.SomeItems, that.SpecialItems)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of some items and of special items must be unique.");
+                }
+
+                if (!Verification.NamesAreUnique(that.Items))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of the items must be unique.");
+                }
+
+                foreach (var error in Verification.Verify_ListOf_IItem(that.Items))
+                {
+                    error.PrependSegment(
+                        new Reporting.NameSegment("items"));
+                    yield return error;
+                }
+
+                foreach (
+                    var error in Verification.Verify_ListOf_ISomeItem(
+                        that.SomeItems))
+                {
+                    error.PrependSegment(
+                        new Reporting.NameSegment("someItems"));
+                    yield return error;
+                }
+
+                if (that.SpecialItems != null)
+                {
+                    foreach (
+                        var error in Verification.Verify_ListOf_ISpecialItem(
+                            that.SpecialItems))
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment("specialItems"));
+                        yield return error;
+                    }
+                }
+            }
+
+            [CodeAnalysis.SuppressMessage("ReSharper", "NegativeEqualityExpression")]
+            public override IEnumerable<Reporting.Error> TransformWrapper(
+                Our.IWrapper that
+            )
+            {
+                if (!(
+                    Verification.ContainerNamesAreUnique(that.Container)))
+                {
+                    yield return new Reporting.Error(
+                        "Invariant violated:\n" +
+                        "Names of some items of the container must be unique.");
+                }
+
+                foreach (var error in Verification.Verify(that.Container))
+                {
+                    error.PrependSegment(
+                        new Reporting.NameSegment("container"));
+                    yield return error;
+                }
+            }
+        }  // private class Transformer
+
+        /// <summary>
+        /// Verify the constraints of <paramref name="that" /> recursively.
+        /// </summary>
+        /// <param name="that">
+        /// The instance of the meta-model to be verified
+        /// </param>
+        public static IEnumerable<Reporting.Error> Verify(Our.IClass that)
+        {
+            foreach (var error in _transformer.Transform(that))
+            {
+                yield return error;
+            }
+        }
+
+        /// <summary>
+        /// Verify the items of <paramref name="that" /> recursively.
+        /// </summary>
+        private static IEnumerable<Reporting.Error> Verify_ListOf_IItem(
+            List<Our.IItem> that)
+        {
+            int index = 0;
+            foreach (var item in that)
+            {
+                foreach (var error in Verification.Verify(item))
+                {
+                    error.PrependSegment(
+                        new Reporting.IndexSegment(index));
+                    yield return error;
+                }
+                index++;
+            }
+        }
+
+        /// <summary>
+        /// Verify the items of <paramref name="that" /> recursively.
+        /// </summary>
+        private static IEnumerable<Reporting.Error> Verify_ListOf_ISomeItem(
+            List<Our.ISomeItem> that)
+        {
+            int index = 0;
+            foreach (var item in that)
+            {
+                foreach (var error in Verification.Verify(item))
+                {
+                    error.PrependSegment(
+                        new Reporting.IndexSegment(index));
+                    yield return error;
+                }
+                index++;
+            }
+        }
+
+        /// <summary>
+        /// Verify the items of <paramref name="that" /> recursively.
+        /// </summary>
+        private static IEnumerable<Reporting.Error> Verify_ListOf_ISpecialItem(
+            List<Our.ISpecialItem> that)
+        {
+            int index = 0;
+            foreach (var item in that)
+            {
+                foreach (var error in Verification.Verify(item))
+                {
+                    error.PrependSegment(
+                        new Reporting.IndexSegment(index));
+                    yield return error;
+                }
+                index++;
+            }
+        }
+    }  // public static class Verification
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/visitation.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/visitation.cs
new file mode 100644
index 000000000..bd04d2a1f
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/visitation.cs
@@ -0,0 +1,311 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+namespace dummy
+{
+    public static class Visitation
+    {
+        /// <summary>
+        /// Define the interface for a visitor which visits the instances of the model.
+        /// </summary>
+        /// <remarks>
+        /// When you use the visitor, please always call the main dispatching method
+        /// <see cref="Visit" />. You should most probably never call the <c>Visit*</c>
+        /// methods directly. They are only made public so that model classes can access them.
+        /// </remarks>
+        public interface IVisitor
+        {
+            public void Visit(IClass that);
+            public void VisitSomeItem(
+                ISomeItem that
+            );
+            public void VisitSpecialItem(
+                ISpecialItem that
+            );
+            public void VisitContainer(
+                IContainer that
+            );
+            public void VisitWrapper(
+                IWrapper that
+            );
+        }  // public interface IVisitor
+
+        /// <summary>
+        /// Just descend through the instances without any action.
+        /// </summary>
+        /// <remarks>
+        /// This class is meaningless for itself. However, it is a good base if you
+        /// want to descend through instances and apply actions only on a subset of
+        /// classes.
+        /// </remarks>
+        public class VisitorThrough : IVisitor
+        {
+            public virtual void Visit(IClass that)
+            {
+                that.Accept(this);
+            }
+
+            public virtual void VisitSomeItem(
+                ISomeItem that
+            )
+            {
+                // Just descend through, do nothing with <c>that</c>
+                foreach (var something in that.DescendOnce())
+                {
+                    Visit(something);
+                }
+            }
+
+            public virtual void VisitSpecialItem(
+                ISpecialItem that
+            )
+            {
+                // Just descend through, do nothing with <c>that</c>
+                foreach (var something in that.DescendOnce())
+                {
+                    Visit(something);
+                }
+            }
+
+            public virtual void VisitContainer(
+                IContainer that
+            )
+            {
+                // Just descend through, do nothing with <c>that</c>
+                foreach (var something in that.DescendOnce())
+                {
+                    Visit(something);
+                }
+            }
+
+            public virtual void VisitWrapper(
+                IWrapper that
+            )
+            {
+                // Just descend through, do nothing with <c>that</c>
+                foreach (var something in that.DescendOnce())
+                {
+                    Visit(something);
+                }
+            }
+        }  // public class VisitorThrough
+
+        /// <summary>
+        /// Perform double-dispatch to visit the concrete instances.
+        /// </summary>
+        public abstract class AbstractVisitor : IVisitor
+        {
+            public virtual void Visit(IClass that)
+            {
+                that.Accept(this);
+            }
+            public abstract void VisitSomeItem(
+                ISomeItem that
+            );
+            public abstract void VisitSpecialItem(
+                ISpecialItem that
+            );
+            public abstract void VisitContainer(
+                IContainer that
+            );
+            public abstract void VisitWrapper(
+                IWrapper that
+            );
+        }  // public abstract class AbstractVisitor
+
+        /// <summary>
+        /// Define the interface for a visitor which visits the instances of the model.
+        /// </summary>
+        /// <remarks>
+        /// When you use the visitor, please always call the main dispatching method
+        /// <see cref="Visit" />. You should most probably never call the <c>Visit*</c>
+        /// methods directly. They are only made public so that model classes can access them.
+        /// </remarks>
+        /// <typeparam name="TContext">Context type</typeparam>
+        public interface IVisitorWithContext<in TContext>
+        {
+            public void Visit(IClass that, TContext context);
+            public void VisitSomeItem(
+                ISomeItem that,
+                TContext context
+            );
+            public void VisitSpecialItem(
+                ISpecialItem that,
+                TContext context
+            );
+            public void VisitContainer(
+                IContainer that,
+                TContext context
+            );
+            public void VisitWrapper(
+                IWrapper that,
+                TContext context
+            );
+        }  // public interface IVisitorWithContext
+
+        /// <summary>
+        /// Perform double-dispatch to visit the concrete instances
+        /// with context.
+        /// </summary>
+        /// <typeparam name="TContext">Context type</typeparam>
+        public abstract class AbstractVisitorWithContext<TContext>
+            : IVisitorWithContext<TContext>
+        {
+            public virtual void Visit(IClass that, TContext context)
+            {
+                that.Accept(this, context);
+            }
+            public abstract void VisitSomeItem(
+                ISomeItem that,
+                TContext context
+            );
+            public abstract void VisitSpecialItem(
+                ISpecialItem that,
+                TContext context
+            );
+            public abstract void VisitContainer(
+                IContainer that,
+                TContext context
+            );
+            public abstract void VisitWrapper(
+                IWrapper that,
+                TContext context
+            );
+        }  // public abstract class AbstractVisitorWithContext
+
+        /// <summary>
+        /// Define the interface for a transformer which transforms recursively
+        /// the instances into something else.
+        /// </summary>
+        /// <remarks>
+        /// When you use the transformer, please always call the main dispatching method
+        /// <see cref="Transform" />. You should most probably never call the <c>Transform*</c>
+        /// methods directly. They are only made public so that model classes can access them.
+        /// </remarks>
+        /// <typeparam name="T">The type of the transformation result</typeparam>
+        public interface ITransformer<out T>
+        {
+            public T Transform(IClass that);
+            public T TransformSomeItem(
+                ISomeItem that
+            );
+            public T TransformSpecialItem(
+                ISpecialItem that
+            );
+            public T TransformContainer(
+                IContainer that
+            );
+            public T TransformWrapper(
+                IWrapper that
+            );
+        }  // public interface ITransformer
+
+        /// <summary>
+        /// Perform double-dispatch to transform recursively
+        /// the instances into something else.
+        /// </summary>
+        /// <typeparam name="T">The type of the transformation result</typeparam>
+        public abstract class AbstractTransformer<T> : ITransformer<T>
+        {
+            public virtual T Transform(IClass that)
+            {
+                return that.Transform(this);
+            }
+
+            public abstract T TransformSomeItem(
+                ISomeItem that
+            );
+
+            public abstract T TransformSpecialItem(
+                ISpecialItem that
+            );
+
+            public abstract T TransformContainer(
+                IContainer that
+            );
+
+            public abstract T TransformWrapper(
+                IWrapper that
+            );
+        }  // public abstract class AbstractTransformer
+
+        /// <summary>
+        /// Define the interface for a transformer which recursively transforms
+        /// the instances into something else while the context is passed along.
+        /// </summary>
+        /// <remarks>
+        /// When you use the transformer, please always call the main dispatching method
+        /// <see cref="Transform" />. You should most probably never call the <c>Transform*</c>
+        /// methods directly. They are only made public so that model classes can access them.
+        /// </remarks>
+        /// <typeparam name="TContext">Type of the transformation context</typeparam>
+        /// <typeparam name="T">The type of the transformation result</typeparam>
+        public interface ITransformerWithContext<in TContext, out T>
+        {
+            public T Transform(IClass that, TContext context);
+            public T TransformSomeItem(
+                ISomeItem that,
+                TContext context
+            );
+            public T TransformSpecialItem(
+                ISpecialItem that,
+                TContext context
+            );
+            public T TransformContainer(
+                IContainer that,
+                TContext context
+            );
+            public T TransformWrapper(
+                IWrapper that,
+                TContext context
+            );
+        }  // public interface ITransformerWithContext
+
+        /// <summary>
+        /// Perform double-dispatch to transform recursively
+        /// the instances into something else.
+        /// </summary>
+        /// <remarks>
+        /// When you use the transformer, please always call the main dispatching method
+        /// <see cref="Transform" />. You should most probably never call the <c>Transform*</c>
+        /// methods directly. They are only made public so that model classes can access them.
+        /// </remarks>
+        /// <typeparam name="TContext">The type of the transformation context</typeparam>
+        /// <typeparam name="T">The type of the transformation result</typeparam>
+        public abstract class AbstractTransformerWithContext<TContext, T>
+            : ITransformerWithContext<TContext, T>
+        {
+            public virtual T Transform(IClass that, TContext context)
+            {
+                return that.Transform(this, context);
+            }
+
+            public abstract T TransformSomeItem(
+                ISomeItem that,
+                TContext context
+            );
+
+            public abstract T TransformSpecialItem(
+                ISpecialItem that,
+                TContext context
+            );
+
+            public abstract T TransformContainer(
+                IContainer that,
+                TContext context
+            );
+
+            public abstract T TransformWrapper(
+                IWrapper that,
+                TContext context
+            );
+        }  // public abstract class AbstractTransformerWithContext
+    }  // public static class Visitation
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlcommon.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlcommon.cs
new file mode 100644
index 000000000..a01ce40b0
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlcommon.cs
@@ -0,0 +1,319 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using Xml = System.Xml;
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide the XML primitives shared by <see cref="Xmlization" /> and
+    /// the de/serialization of the JSON-able values.
+    /// </summary>
+    internal static class XmlCommon
+    {
+        /// <summary>
+        /// XML namespace in which all the elements of a document reside
+        /// </summary>
+        /// <remarks>
+        /// The elements of the XML-RPC subset, over which a JSON-able value is
+        /// de/serialized, are the one exception: they reside in no namespace at all.
+        /// </remarks>
+        internal static readonly string NS = (
+            "https://dummy.com");
+
+        /// <summary>
+        /// Move <paramref name="reader" /> past the nodes which carry no
+        /// information -- the whitespace between the tags and the comments.
+        /// </summary>
+        internal static void SkipNoneWhitespaceAndComments(
+            Xml.XmlReader reader)
+        {
+            while (
+                !reader.EOF
+                && (
+                    reader.NodeType == Xml.XmlNodeType.None
+                    || reader.NodeType == Xml.XmlNodeType.Whitespace
+                    || reader.NodeType == Xml.XmlNodeType.Comment))
+            {
+                reader.Read();
+            }
+        }
+
+        /// <summary>
+        /// Check that the element resides in <paramref name="ns" /> and extract
+        /// its name.
+        /// </summary>
+        private static string TryElementNameInNamespace(
+            Xml.XmlReader reader,
+            string ns,
+            out Reporting.Error? error
+            )
+        {
+            // Pre-condition
+            if (reader.NodeType != Xml.XmlNodeType.Element
+                && reader.NodeType != Xml.XmlNodeType.EndElement)
+            {
+                throw new System.InvalidOperationException(
+                    "Expected to be at a start or an end element " +
+                    $"in {nameof(TryElementNameInNamespace)}, " +
+                    $"but got: {reader.NodeType}");
+            }
+
+            error = null;
+            if (reader.NamespaceURI != ns)
+            {
+                string expected = (
+                    (ns.Length == 0)
+                        ? "no namespace"
+                        : $"the namespace {ns}");
+                string got = (
+                    (reader.NamespaceURI.Length == 0)
+                        ? "no namespace"
+                        : $"the namespace {reader.NamespaceURI}");
+
+                error = new Reporting.Error(
+                    $"Expected an element within {expected}, " +
+                    $"but got an element within {got}");
+                return "";
+            }
+
+            return reader.LocalName;
+        }
+
+        /// <summary>
+        /// Consume the start tag of an element named
+        /// <paramref name="expectedName" /> and tell whether that element was
+        /// self-closing and hence has no content and no end tag.
+        /// </summary>
+        /// <remarks>
+        /// On failure the returned value is meaningless; the caller checks
+        /// <paramref name="error" /> first.
+        /// </remarks>
+        private static bool ReadStartElementInNamespace(
+            Xml.XmlReader reader,
+            string ns,
+            string expectedName,
+            out Reporting.Error? error
+            )
+        {
+            error = null;
+
+            SkipNoneWhitespaceAndComments(reader);
+
+            if (reader.EOF)
+            {
+                error = new Reporting.Error(
+                    $"Expected a <{expectedName}> element, " +
+                    "but reached the end-of-file");
+                return false;
+            }
+
+            if (reader.NodeType != Xml.XmlNodeType.Element)
+            {
+                error = new Reporting.Error(
+                    $"Expected a <{expectedName}> element, " +
+                    $"but got a node of type {reader.NodeType} " +
+                    $"with value {reader.Value}");
+                return false;
+            }
+
+            string observedName = TryElementNameInNamespace(
+                reader, ns, out error);
+            if (error != null)
+            {
+                return false;
+            }
+
+            if (observedName != expectedName)
+            {
+                error = new Reporting.Error(
+                    $"Expected a <{expectedName}> element, " +
+                    $"but got a <{observedName}> element");
+                return false;
+            }
+
+            bool isEmptyElement = reader.IsEmptyElement;
+
+            // Consume the start tag and go to the content.
+            reader.Read();
+
+            return isEmptyElement;
+        }
+
+        /// <summary>
+        /// Consume the end tag matching <paramref name="elementName" />, unless
+        /// <paramref name="isEmptyElement" /> tells that the element was
+        /// self-closing and thus has no end tag at all.
+        /// </summary>
+        private static void ConsumeEndElementInNamespace(
+            Xml.XmlReader reader,
+            string ns,
+            string elementName,
+            bool isEmptyElement,
+            out Reporting.Error? error
+            )
+        {
+            error = null;
+
+            if (isEmptyElement)
+            {
+                return;
+            }
+
+            SkipNoneWhitespaceAndComments(reader);
+
+            if (reader.EOF)
+            {
+                error = new Reporting.Error(
+                    $"Expected a closing element </{elementName}>, " +
+                    "but reached the end-of-file");
+                return;
+            }
+
+            if (reader.NodeType != Xml.XmlNodeType.EndElement)
+            {
+                error = new Reporting.Error(
+                    $"Expected a closing element </{elementName}>, " +
+                    $"but got a node of type {reader.NodeType} " +
+                    $"with value {reader.Value}");
+                return;
+            }
+
+            string endElementName = TryElementNameInNamespace(
+                reader, ns, out error);
+            if (error != null)
+            {
+                return;
+            }
+
+            if (endElementName != elementName)
+            {
+                error = new Reporting.Error(
+                    $"Expected a closing element </{elementName}>, " +
+                    $"but got a closing element </{endElementName}>");
+                return;
+            }
+
+            // Consume the end tag.
+            reader.Read();
+        }
+
+        /// <summary>
+        /// Check that the element resides in <see cref="NS" /> and extract its name.
+        /// </summary>
+        internal static string TryElementName(
+            Xml.XmlReader reader,
+            out Reporting.Error? error
+            )
+        {
+            return TryElementNameInNamespace(reader, NS, out error);
+        }
+
+        /// <summary>
+        /// Consume the start tag of an element named
+        /// <paramref name="expectedName" /> in <see cref="NS" />, and tell whether
+        /// that element was self-closing.
+        /// </summary>
+        internal static bool ReadStartElement(
+            Xml.XmlReader reader,
+            string expectedName,
+            out Reporting.Error? error
+            )
+        {
+            return ReadStartElementInNamespace(
+                reader, NS, expectedName, out error);
+        }
+
+        /// <summary>
+        /// Consume the end tag matching <paramref name="elementName" /> in
+        /// <see cref="NS" />, unless the element was self-closing.
+        /// </summary>
+        internal static void ConsumeEndElement(
+            Xml.XmlReader reader,
+            string elementName,
+            bool isEmptyElement,
+            out Reporting.Error? error
+            )
+        {
+            ConsumeEndElementInNamespace(
+                reader, NS, elementName, isEmptyElement, out error);
+        }
+
+        /// <summary>
+        /// Look ahead the name of the element at the current position of
+        /// <paramref name="reader" />, without consuming anything.
+        /// </summary>
+        internal static string PeekElementName(
+            Xml.XmlReader reader,
+            out Reporting.Error? error
+            )
+        {
+            error = null;
+
+            SkipNoneWhitespaceAndComments(reader);
+
+            if (reader.EOF)
+            {
+                error = new Reporting.Error(
+                    "Expected an XML element, but reached the end-of-file");
+                return "";
+            }
+
+            if (reader.NodeType != Xml.XmlNodeType.Element)
+            {
+                error = new Reporting.Error(
+                    "Expected an XML element, " +
+                    $"but got a node of type {reader.NodeType} " +
+                    $"with value {reader.Value}");
+                return "";
+            }
+
+            return TryElementNameInNamespace(
+                reader, NS, out error);
+        }
+    }  // internal static class XmlCommon
+
+    /// <summary>
+    /// Signal a failure of the serialization, carrying the path to the culprit.
+    /// </summary>
+    /// <remarks>
+    /// The path is built as the stack unwinds -- every container prepends the one
+    /// segment it knows, the property its name and the list the index of the item
+    /// -- which is why this can not be a <see cref="SerializationException" />
+    /// already: that one renders its message in its constructor, so its path has
+    /// to be complete by then. <see cref="Xmlization.Serialize.To" /> renders and
+    /// converts.
+    /// </remarks>
+    internal class SerializationFailure : System.Exception
+    {
+        public readonly Reporting.Error Error;
+        public SerializationFailure(Reporting.Error error)
+            : base(error.Cause)
+        {
+            Error = error;
+        }
+    }
+
+    /// <summary>
+    /// Represent a critical error during the serialization to XML.
+    /// </summary>
+    public class SerializationException : System.Exception
+    {
+        public readonly string Path;
+        public readonly string Cause;
+        public SerializationException(string path, string cause)
+            : base($"{cause} at: {(path == "" ? "the instance itself" : path)}")
+        {
+            Path = path;
+            Cause = cause;
+        }
+    }
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlization.cs b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlization.cs
new file mode 100644
index 000000000..aad2d8e53
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/dummy/xmlization.cs
@@ -0,0 +1,1599 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+using Our = dummy;  // renamed
+using CodeAnalysis = System.Diagnostics.CodeAnalysis;
+using Xml = System.Xml;
+
+using System.Collections.Generic;  // can't alias
+
+namespace dummy
+{
+    /// <summary>
+    /// Provide de/serialization of meta-model classes to/from XML.
+    /// </summary>
+    public static class Xmlization
+    {
+        /// The XML namespace of the meta-model
+        [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+        public static readonly string NS = XmlCommon.NS;
+
+        /// <summary>
+        /// Implement the deserialization of meta-model classes from XML.
+        /// </summary>
+        /// <remarks>
+        /// The implementation propagates an <see cref="Reporting.Error" /> instead of
+        /// relying on exceptions. Under the assumption that incorrect data is much less
+        /// frequent than correct data, this makes the deserialization more
+        /// efficient.
+        ///
+        /// However, we do not want to force the client to deal with
+        /// the <see cref="Reporting.Error" /> class as this is not intuitive.
+        /// Therefore we distinguish the implementation, realized in
+        /// <see cref="DeserializeImplementation" />, and the facade given in
+        /// <see cref="Deserialize" /> class.
+        /// </remarks>
+        internal static class DeserializeImplementation
+        {
+            /// <summary>
+            /// Read a single element, tags included, positioned at its start tag.
+            /// </summary>
+            /// <remarks>
+            /// Return the value; on failure it is meaningless and
+            /// <paramref name="error" /> says why. A plain <c>T</c> rather than
+            /// a <c>T?</c>, so that one unconstrained delegate serves both the value
+            /// and the reference types.
+            ///
+            /// <typeparamref name="T" /> is covariant, so that the reader of
+            /// a concrete class can be used as the reader of an item of a list of
+            /// its interface. It is <c>internal</c> only because the readers of
+            /// the classes are, and a field may not be more accessible than its type.
+            /// </remarks>
+            /// <typeparam name="T">Type of the parsed value</typeparam>
+            internal delegate T ElementReader<out T>(
+                Xml.XmlReader reader,
+                out Reporting.Error? error);
+
+            /// <summary>
+            /// Read the content of an element, positioned after its start tag.
+            /// </summary>
+            /// <remarks>
+            /// Every value is read through this one shape, so that the reading can be
+            /// composed: an <c>As*</c> combinator turns a conversion, a literal parser,
+            /// an element reader or a list of them into one of these, and a class's own
+            /// <c>...FromSequence</c> already is one.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value</typeparam>
+            private delegate T ContentReader<T>(
+                Xml.XmlReader reader,
+                bool isEmpty,
+                out Reporting.Error? error);
+
+            /// <summary>
+            /// Convert the content at the current position of <paramref name="reader" />.
+            /// </summary>
+            /// <typeparam name="T">Type to convert the content to</typeparam>
+            private delegate T ContentConverter<T>(Xml.XmlReader reader);
+
+            /// <summary>
+            /// Read the content between a start and an end tag and convert it
+            /// with <paramref name="readContent" />.
+            /// </summary>
+            /// <remarks>
+            /// This is the one skeleton for reading any content whatsoever -- of
+            /// a property, or of a <c>&lt;v&gt;</c> element of a list or a tuple item
+            /// (see <see cref="AtElement{T}" />). Only the conversion differs, so
+            /// only the conversion is passed in.
+            ///
+            /// On failure the returned value is meaningless; the caller checks
+            /// <paramref name="error" /> and bails out before ever reading it. That is
+            /// what lets this return a plain <c>T</c> -- a <c>T?</c> would have to be
+            /// split into a variant for the value and one for the reference types.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value</typeparam>
+            private static ContentReader<T> AsText<T>(
+                ContentConverter<T> readContent
+                )
+            {
+                return (
+                    Xml.XmlReader reader,
+                    bool isEmpty,
+                    out Reporting.Error? error
+                ) =>
+                {
+                    error = null;
+
+                    if (isEmpty)
+                    {
+                        error = new Reporting.Error(
+                            $"Expected an XML content representing {typeof(T).Name}, " +
+                            "but the element was self-closing");
+                        return default!;
+                    }
+
+                    if (reader.EOF)
+                    {
+                        error = new Reporting.Error(
+                            $"Expected an XML content representing {typeof(T).Name}, " +
+                            "but reached the end-of-file");
+                        return default!;
+                    }
+
+                    // NOTE (mristin):
+                    // XmlReader.ReadContentAs* throws an InvalidOperationException if it
+                    // starts at an element, so we have to report a nested element before
+                    // the conversion. A nested element after a text is not our concern
+                    // here, as the caller expects the end element afterwards.
+                    if (reader.NodeType == Xml.XmlNodeType.Element)
+                    {
+                        error = new Reporting.Error(
+                            $"Expected an XML content representing {typeof(T).Name}, " +
+                            $"but got a nested element {reader.Name}");
+                        return default!;
+                    }
+
+                    try
+                    {
+                        return readContent(reader);
+                    }
+                    catch (System.Exception exception)
+                            when (exception is System.FormatException
+                                || exception is System.Xml.XmlException
+                                // NOTE (mristin):
+                                // An integer beyond the range of a long leaves
+                                // ReadContentAsLong as an OverflowException, which is neither
+                                // of the two above, so it used to escape this filter and leave
+                                // the de-serialization through an exception we never declared.
+                                || exception is System.OverflowException)
+                    {
+                        error = new Reporting.Error(
+                            $"The content could not be de-serialized as {typeof(T).Name}: " +
+                            exception.Message);
+                        return default!;
+                    }
+                };
+            }
+
+            /// <summary>
+            /// Read the content between a start and an end tag, or return
+            /// <paramref name="whenEmpty" /> if the element was self-closing.
+            /// </summary>
+            /// <typeparam name="T">Type of the value</typeparam>
+            [CodeAnalysis.SuppressMessage("ReSharper", "UnusedMember.Local")]
+            private static ContentReader<T> AsText<T>(
+                ContentConverter<T> readContent,
+                T whenEmpty
+                )
+            {
+                ContentReader<T> readText = AsText<T>(readContent);
+
+                return (
+                    Xml.XmlReader reader,
+                    bool isEmpty,
+                    out Reporting.Error? error
+                ) =>
+                {
+                    if (isEmpty)
+                    {
+                        error = null;
+                        return whenEmpty;
+                    }
+
+                    return readText(reader, false, out error);
+                };
+            }
+
+            /// <summary>
+            /// Convert the content at the current position of <paramref name="reader" />
+            /// to long.
+            /// </summary>
+            private static long ReadContentAsLong(Xml.XmlReader reader)
+            {
+                return reader.ReadContentAsLong();
+            }
+
+            /// <summary>
+            /// Convert the content at the current position of <paramref name="reader" />
+            /// to string.
+            /// </summary>
+            private static string ReadContentAsString(Xml.XmlReader reader)
+            {
+                return reader.ReadContentAsString();
+            }
+
+            /// <summary>
+            /// Bind <paramref name="elementName" /> to <paramref name="readContent" />,
+            /// so that the result reads the whole element, tags included.
+            /// </summary>
+            /// <typeparam name="T">Type of the parsed value</typeparam>
+            private static ElementReader<T> AtElement<T>(
+                ContentReader<T> readContent,
+                string elementName
+                )
+            {
+                return (
+                    Xml.XmlReader reader,
+                    out Reporting.Error? error
+                ) =>
+                {
+                    bool isEmptyElement = XmlCommon.ReadStartElement(
+                        reader, elementName, out error);
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+
+                    T value = readContent(reader, isEmptyElement, out error);
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+
+                    XmlCommon.ConsumeEndElement(
+                        reader, elementName, isEmptyElement, out error);
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+
+                    return value;
+                };
+            }
+
+            /// <summary>
+            /// Read the start tag of the next property of a sequence and return whether
+            /// there was one.
+            /// </summary>
+            /// <remarks>
+            /// A sequence ends at the end tag of the enclosing element or at the end of
+            /// the file, which is not a failure -- when this returns <c>false</c>,
+            /// <paramref name="error" /> tells the two apart.
+            ///
+            /// The start tag is consumed, so the reader is left at the content of
+            /// the property.
+            /// </remarks>
+            private static bool TryNextProperty(
+                Xml.XmlReader reader,
+                out string elementName,
+                out bool isEmptyProperty,
+                out Reporting.Error? error
+                )
+            {
+                error = null;
+                elementName = "";
+                isEmptyProperty = false;
+
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (reader.NodeType == Xml.XmlNodeType.EndElement || reader.EOF)
+                {
+                    return false;
+                }
+
+                if (reader.NodeType != Xml.XmlNodeType.Element)
+                {
+                    error = new Reporting.Error(
+                        "Expected an XML start element representing a property, " +
+                        $"but got the node of type {reader.NodeType} " +
+                        $"with the value {reader.Value}");
+                    return false;
+                }
+
+                elementName = XmlCommon.TryElementName(
+                    reader, out error);
+                if (error != null)
+                {
+                    return false;
+                }
+
+                isEmptyProperty = reader.IsEmptyElement;
+
+                // Consume the start tag and go to the content.
+                reader.Read();
+
+                return true;
+            }
+
+            /// <summary>
+            /// Report a property which the sequence of the properties gave more than once.
+            /// </summary>
+            private static Reporting.Error DuplicatePropertyError(string elementName)
+            {
+                return new Reporting.Error(
+                    $"Property {elementName} occurred more than once");
+            }
+
+            /// <summary>
+            /// Read a sequence of list items with <paramref name="readItem" />,
+            /// stopping (without consuming) at the first non-element node.
+            /// </summary>
+            /// <remarks>
+            /// This is shared by everything of a list type, whatever its items are and
+            /// however deeply it is nested, since the items are read through
+            /// an <see cref="ElementReader{T}" /> like any other element.
+            /// </remarks>
+            /// <typeparam name="T">Type of a single list item</typeparam>
+            private static List<T> ReadList<T>(
+                Xml.XmlReader reader,
+                ElementReader<T> readItem,
+                out Reporting.Error? error
+                )
+            {
+                error = null;
+                var result = new List<T>();
+
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                int index = 0;
+                while (reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    T item = readItem(reader, out error);
+                    if (error != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.IndexSegment(
+                                index));
+                        return result;
+                    }
+
+                    result.Add(item);
+
+                    index++;
+                    XmlCommon.SkipNoneWhitespaceAndComments(reader);
+                }
+
+                return result;
+            }
+
+            /// <summary>
+            /// Read a content as a list of items, each read with
+            /// <paramref name="readItem" />.
+            /// </summary>
+            /// <remarks>
+            /// A self-closing element represents an empty list.
+            /// </remarks>
+            /// <typeparam name="T">Type of a single list item</typeparam>
+            private static ContentReader<List<T>> AsList<T>(
+                ElementReader<T> readItem
+                )
+            {
+                return (
+                    Xml.XmlReader reader,
+                    bool isEmpty,
+                    out Reporting.Error? error
+                ) =>
+                {
+                    error = null;
+
+                    if (isEmpty)
+                    {
+                        return new List<T>();
+                    }
+
+                    return ReadList<T>(
+                        reader, readItem, out error);
+                };
+            }
+
+            /// <summary>
+            /// Read an instance of class SomeItem from its XML element.
+            /// </summary>
+            internal static readonly ElementReader<Our.SomeItem> SomeItemFromElement = (
+                AtElement<Our.SomeItem>(
+                    SomeItemFromSequence, "someItem"));
+
+            /// <summary>
+            /// Read an instance of class SpecialItem from its XML element.
+            /// </summary>
+            internal static readonly ElementReader<Our.SpecialItem> SpecialItemFromElement = (
+                AtElement<Our.SpecialItem>(
+                    SpecialItemFromSequence, "specialItem"));
+
+            /// <summary>
+            /// Read an instance of class Container from its XML element.
+            /// </summary>
+            internal static readonly ElementReader<Our.Container> ContainerFromElement = (
+                AtElement<Our.Container>(
+                    ContainerFromSequence, "container"));
+
+            /// <summary>
+            /// Read an instance of class Wrapper from its XML element.
+            /// </summary>
+            internal static readonly ElementReader<Our.Wrapper> WrapperFromElement = (
+                AtElement<Our.Wrapper>(
+                    WrapperFromSequence, "wrapper"));
+
+            private static readonly ContentReader<string> Read_string = (
+                AsText<string>(ReadContentAsString, ""));
+
+            private static readonly ContentReader<long> Read_long = (
+                AsText<long>(ReadContentAsLong));
+
+            private static readonly ContentReader<List<IItem>> Read_ListOf_IItem = (
+                AsList<IItem>(
+                    IItemFromElement));
+
+            private static readonly ContentReader<List<ISomeItem>> Read_ListOf_ISomeItem = (
+                AsList<ISomeItem>(
+                    ISomeItemFromElement));
+
+            private static readonly ContentReader<List<ISpecialItem>> Read_ListOf_ISpecialItem = (
+                AsList<ISpecialItem>(
+                    SpecialItemFromElement));
+
+            private static readonly ContentReader<IContainer> Read_IContainer = (
+                ContainerFromSequence);
+
+            /// <summary>
+            /// Deserialize an instance of IItem from an XML element.
+            /// </summary>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            internal static Our.IItem IItemFromElement(
+                Xml.XmlReader reader,
+                out Reporting.Error? error)
+            {
+                string elementName = XmlCommon.PeekElementName(
+                    reader, out error);
+                if (error != null)
+                {
+                    return default!;
+                }
+
+                switch (elementName)
+                {
+                    case "someItem":
+                        return SomeItemFromElement(
+                            reader, out error);
+                    case "specialItem":
+                        return SpecialItemFromElement(
+                            reader, out error);
+                    default:
+                        error = new Reporting.Error(
+                            $"Unexpected element with the name {elementName}");
+                        return default!;
+                }
+            }  // internal static Our.IItem? IItemFromElement
+
+            /// <summary>
+            /// Deserialize an instance of class SomeItem from a sequence of XML elements.
+            /// </summary>
+            /// <remarks>
+            /// If <paramref name="isEmptySequence" /> is set, we should try to deserialize
+            /// the instance from an empty sequence. That is, the parent element
+            /// was a self-closing element.
+            /// </remarks>
+            internal static Our.SomeItem SomeItemFromSequence(
+                Xml.XmlReader reader,
+                bool isEmptySequence,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                string? theName = null;
+                string? theNickname = null;
+
+                if (!isEmptySequence)
+                {
+                    XmlCommon.SkipNoneWhitespaceAndComments(reader);
+                    if (reader.EOF)
+                    {
+                        error = new Reporting.Error(
+                            "Expected an XML element representing " +
+                            "a property of an instance of class SomeItem, " +
+                            "but reached the end-of-file");
+                        return default!;
+                    }
+                    while (TryNextProperty(
+                            reader,
+                            out string elementName,
+                            out bool isEmptyProperty,
+                            out error))
+                    {
+                        switch (elementName)
+                        {
+                            case "name":
+                                if (theName != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theName = Read_string(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            case "nickname":
+                                if (theNickname != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theNickname = Read_string(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            default:
+                                error = new Reporting.Error(
+                                    "We expected properties of the class SomeItem, " +
+                                    "but got an unexpected element " +
+                                    $"with the name {elementName}");
+                                return default!;
+                        }
+
+                        if (error == null)
+                        {
+                            XmlCommon.ConsumeEndElement(
+                                reader, elementName, isEmptyProperty, out error);
+                        }
+
+                        // NOTE (mristin):
+                        // Every property is read in this very loop, so we mark the error with
+                        // the property's own element name here, once, instead of at every
+                        // single case above. For a matched case, elementName *is* that name.
+                        // This covers the end element of the property as well, since whatever
+                        // unexpected node precedes it still lies within the property.
+                        if (error != null)
+                        {
+                            error.PrependSegment(
+                                new Reporting.NameSegment(
+                                    elementName));
+                            return default!;
+                        }
+                    }
+
+                    // NOTE (mristin):
+                    // The loop also ends when the next property could not be read at all,
+                    // which is the only way out of it that is a failure.
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+                }
+
+                if (theName == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property Name has not been given " +
+                        "in the XML representation of an instance of class SomeItem");
+                    return default!;
+                }
+
+                return new Our.SomeItem(
+                    theName
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theNickname);
+            }  // internal static Our.SomeItem? SomeItemFromSequence
+
+            /// <summary>
+            /// Deserialize an instance of ISomeItem from an XML element.
+            /// </summary>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            internal static Our.ISomeItem ISomeItemFromElement(
+                Xml.XmlReader reader,
+                out Reporting.Error? error)
+            {
+                string elementName = XmlCommon.PeekElementName(
+                    reader, out error);
+                if (error != null)
+                {
+                    return default!;
+                }
+
+                switch (elementName)
+                {
+                    case "specialItem":
+                        return SpecialItemFromElement(
+                            reader, out error);
+                    case "someItem":
+                        return SomeItemFromElement(
+                            reader, out error);
+                    default:
+                        error = new Reporting.Error(
+                            $"Unexpected element with the name {elementName}");
+                        return default!;
+                }
+            }  // internal static Our.ISomeItem? ISomeItemFromElement
+
+            /// <summary>
+            /// Deserialize an instance of class SpecialItem from a sequence of XML elements.
+            /// </summary>
+            /// <remarks>
+            /// If <paramref name="isEmptySequence" /> is set, we should try to deserialize
+            /// the instance from an empty sequence. That is, the parent element
+            /// was a self-closing element.
+            /// </remarks>
+            internal static Our.SpecialItem SpecialItemFromSequence(
+                Xml.XmlReader reader,
+                bool isEmptySequence,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                string? theName = null;
+                string? theNickname = null;
+                long? theLevel = null;
+
+                if (!isEmptySequence)
+                {
+                    XmlCommon.SkipNoneWhitespaceAndComments(reader);
+                    if (reader.EOF)
+                    {
+                        error = new Reporting.Error(
+                            "Expected an XML element representing " +
+                            "a property of an instance of class SpecialItem, " +
+                            "but reached the end-of-file");
+                        return default!;
+                    }
+                    while (TryNextProperty(
+                            reader,
+                            out string elementName,
+                            out bool isEmptyProperty,
+                            out error))
+                    {
+                        switch (elementName)
+                        {
+                            case "name":
+                                if (theName != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theName = Read_string(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            case "nickname":
+                                if (theNickname != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theNickname = Read_string(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            case "level":
+                                if (theLevel != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theLevel = Read_long(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            default:
+                                error = new Reporting.Error(
+                                    "We expected properties of the class SpecialItem, " +
+                                    "but got an unexpected element " +
+                                    $"with the name {elementName}");
+                                return default!;
+                        }
+
+                        if (error == null)
+                        {
+                            XmlCommon.ConsumeEndElement(
+                                reader, elementName, isEmptyProperty, out error);
+                        }
+
+                        // NOTE (mristin):
+                        // Every property is read in this very loop, so we mark the error with
+                        // the property's own element name here, once, instead of at every
+                        // single case above. For a matched case, elementName *is* that name.
+                        // This covers the end element of the property as well, since whatever
+                        // unexpected node precedes it still lies within the property.
+                        if (error != null)
+                        {
+                            error.PrependSegment(
+                                new Reporting.NameSegment(
+                                    elementName));
+                            return default!;
+                        }
+                    }
+
+                    // NOTE (mristin):
+                    // The loop also ends when the next property could not be read at all,
+                    // which is the only way out of it that is a failure.
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+                }
+
+                if (theName == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property Name has not been given " +
+                        "in the XML representation of an instance of class SpecialItem");
+                    return default!;
+                }
+
+                if (theLevel == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property Level has not been given " +
+                        "in the XML representation of an instance of class SpecialItem");
+                    return default!;
+                }
+
+                return new Our.SpecialItem(
+                    theName
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theLevel
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theNickname);
+            }  // internal static Our.SpecialItem? SpecialItemFromSequence
+
+            /// <summary>
+            /// Deserialize an instance of class Container from a sequence of XML elements.
+            /// </summary>
+            /// <remarks>
+            /// If <paramref name="isEmptySequence" /> is set, we should try to deserialize
+            /// the instance from an empty sequence. That is, the parent element
+            /// was a self-closing element.
+            /// </remarks>
+            internal static Our.Container ContainerFromSequence(
+                Xml.XmlReader reader,
+                bool isEmptySequence,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                List<IItem>? theItems = null;
+                List<ISomeItem>? theSomeItems = null;
+                List<ISpecialItem>? theSpecialItems = null;
+
+                if (!isEmptySequence)
+                {
+                    XmlCommon.SkipNoneWhitespaceAndComments(reader);
+                    if (reader.EOF)
+                    {
+                        error = new Reporting.Error(
+                            "Expected an XML element representing " +
+                            "a property of an instance of class Container, " +
+                            "but reached the end-of-file");
+                        return default!;
+                    }
+                    while (TryNextProperty(
+                            reader,
+                            out string elementName,
+                            out bool isEmptyProperty,
+                            out error))
+                    {
+                        switch (elementName)
+                        {
+                            case "items":
+                                if (theItems != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theItems = Read_ListOf_IItem(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            case "someItems":
+                                if (theSomeItems != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theSomeItems = Read_ListOf_ISomeItem(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            case "specialItems":
+                                if (theSpecialItems != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theSpecialItems = Read_ListOf_ISpecialItem(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            default:
+                                error = new Reporting.Error(
+                                    "We expected properties of the class Container, " +
+                                    "but got an unexpected element " +
+                                    $"with the name {elementName}");
+                                return default!;
+                        }
+
+                        if (error == null)
+                        {
+                            XmlCommon.ConsumeEndElement(
+                                reader, elementName, isEmptyProperty, out error);
+                        }
+
+                        // NOTE (mristin):
+                        // Every property is read in this very loop, so we mark the error with
+                        // the property's own element name here, once, instead of at every
+                        // single case above. For a matched case, elementName *is* that name.
+                        // This covers the end element of the property as well, since whatever
+                        // unexpected node precedes it still lies within the property.
+                        if (error != null)
+                        {
+                            error.PrependSegment(
+                                new Reporting.NameSegment(
+                                    elementName));
+                            return default!;
+                        }
+                    }
+
+                    // NOTE (mristin):
+                    // The loop also ends when the next property could not be read at all,
+                    // which is the only way out of it that is a failure.
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+                }
+
+                if (theItems == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property Items has not been given " +
+                        "in the XML representation of an instance of class Container");
+                    return default!;
+                }
+
+                if (theSomeItems == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property SomeItems has not been given " +
+                        "in the XML representation of an instance of class Container");
+                    return default!;
+                }
+
+                return new Our.Container(
+                    theItems
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theSomeItems
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"),
+                    theSpecialItems);
+            }  // internal static Our.Container? ContainerFromSequence
+
+            /// <summary>
+            /// Deserialize an instance of class Wrapper from a sequence of XML elements.
+            /// </summary>
+            /// <remarks>
+            /// If <paramref name="isEmptySequence" /> is set, we should try to deserialize
+            /// the instance from an empty sequence. That is, the parent element
+            /// was a self-closing element.
+            /// </remarks>
+            internal static Our.Wrapper WrapperFromSequence(
+                Xml.XmlReader reader,
+                bool isEmptySequence,
+                out Reporting.Error? error)
+            {
+                error = null;
+
+                IContainer? theContainer = null;
+
+                if (!isEmptySequence)
+                {
+                    XmlCommon.SkipNoneWhitespaceAndComments(reader);
+                    if (reader.EOF)
+                    {
+                        error = new Reporting.Error(
+                            "Expected an XML element representing " +
+                            "a property of an instance of class Wrapper, " +
+                            "but reached the end-of-file");
+                        return default!;
+                    }
+                    while (TryNextProperty(
+                            reader,
+                            out string elementName,
+                            out bool isEmptyProperty,
+                            out error))
+                    {
+                        switch (elementName)
+                        {
+                            case "container":
+                                if (theContainer != null)
+                                {
+                                    error = DuplicatePropertyError(elementName);
+                                    break;
+                                }
+                                theContainer = Read_IContainer(
+                                    reader, isEmptyProperty, out error);
+                                break;
+                            default:
+                                error = new Reporting.Error(
+                                    "We expected properties of the class Wrapper, " +
+                                    "but got an unexpected element " +
+                                    $"with the name {elementName}");
+                                return default!;
+                        }
+
+                        if (error == null)
+                        {
+                            XmlCommon.ConsumeEndElement(
+                                reader, elementName, isEmptyProperty, out error);
+                        }
+
+                        // NOTE (mristin):
+                        // Every property is read in this very loop, so we mark the error with
+                        // the property's own element name here, once, instead of at every
+                        // single case above. For a matched case, elementName *is* that name.
+                        // This covers the end element of the property as well, since whatever
+                        // unexpected node precedes it still lies within the property.
+                        if (error != null)
+                        {
+                            error.PrependSegment(
+                                new Reporting.NameSegment(
+                                    elementName));
+                            return default!;
+                        }
+                    }
+
+                    // NOTE (mristin):
+                    // The loop also ends when the next property could not be read at all,
+                    // which is the only way out of it that is a failure.
+                    if (error != null)
+                    {
+                        return default!;
+                    }
+                }
+
+                if (theContainer == null)
+                {
+                    error = new Reporting.Error(
+                        "The required property Container has not been given " +
+                        "in the XML representation of an instance of class Wrapper");
+                    return default!;
+                }
+
+                return new Our.Wrapper(
+                    theContainer
+                         ?? throw new System.InvalidOperationException(
+                            "Unexpected null, had to be handled before"));
+            }  // internal static Our.Wrapper? WrapperFromSequence
+        }  // internal static class DeserializeImplementation
+
+        /// <summary>
+        /// Represent a critical error during the deserialization.
+        /// </summary>
+        public class Exception : System.Exception
+        {
+            public readonly string Path;
+            public readonly string Cause;
+            public Exception(string path, string cause)
+                : base($"{cause} at: {(path == "" ? "the beginning" : path)}")
+            {
+                Path = path;
+                Cause = cause;
+            }
+        }
+
+        /// <summary>
+        /// Deserialize instances of meta-model classes from XML.
+        /// </summary>
+        /// <example>
+        /// Here is an example how to parse an instance of class IItem:
+        /// <code>
+        /// var reader = new System.Xml.XmlReader(/* some arguments */);
+        /// Our.IItem anInstance = Deserialize.IItemFrom(
+        ///     reader);
+        /// </code>
+        /// </example>
+        ///
+        /// <remarks>
+        /// The elements are expected to live in <see cref="NS" />, the one XML
+        /// namespace of the meta-model, so there is nothing to supply.
+        /// </remarks>
+        public static class Deserialize
+        {
+            /// <summary>
+            /// Deserialize an instance of IItem from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of IItem.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]public static Our.IItem IItemFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class IItem, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.IItem result = DeserializeImplementation.IItemFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of ISomeItem from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of ISomeItem.
+            /// </exception>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]public static Our.ISomeItem ISomeItemFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class ISomeItem, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.ISomeItem result = DeserializeImplementation.ISomeItemFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of SomeItem from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of SomeItem.
+            /// </exception>
+            public static Our.SomeItem SomeItemFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class SomeItem, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.SomeItem result = DeserializeImplementation.SomeItemFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of SpecialItem from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of SpecialItem.
+            /// </exception>
+            public static Our.SpecialItem SpecialItemFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class SpecialItem, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.SpecialItem result = DeserializeImplementation.SpecialItemFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of Container from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of Container.
+            /// </exception>
+            public static Our.Container ContainerFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class Container, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.Container result = DeserializeImplementation.ContainerFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+
+            /// <summary>
+            /// Deserialize an instance of Wrapper from <paramref name="reader" />.
+            /// </summary>
+            /// <param name="reader">Initialized XML reader with cursor set to the element</param>
+            /// <exception cref="Xmlization.Exception">
+            /// Thrown when the element is not a valid XML
+            /// representation of Wrapper.
+            /// </exception>
+            public static Our.Wrapper WrapperFrom(
+                Xml.XmlReader reader)
+            {
+                XmlCommon.SkipNoneWhitespaceAndComments(reader);
+
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.XmlDeclaration)
+                {
+                    throw new Xmlization.Exception(
+                        "",
+                        "Unexpected XML declaration when reading an instance " +
+                        "of class Wrapper, as we expect the reader " +
+                        "to be set at content with MoveToContent");
+                }
+
+                // NOTE (mristin):
+                // The path starts at the root element. The readers do not prepend their own
+                // names, so we prepend the name of the root element here, if there is any.
+                string? rootElementName = null;
+                if (!reader.EOF && reader.NodeType == Xml.XmlNodeType.Element)
+                {
+                    rootElementName = reader.LocalName;
+                }
+
+                Our.Wrapper result = DeserializeImplementation.WrapperFromElement(
+                    reader,
+                    out Reporting.Error? error);
+                if (error != null)
+                {
+                    if (rootElementName != null)
+                    {
+                        error.PrependSegment(
+                            new Reporting.NameSegment(rootElementName));
+                    }
+                    throw new Xmlization.Exception(
+                        Reporting.GenerateRelativeXPath(error.PathSegments),
+                        error.Cause);
+                }
+                return result;
+            }
+        }  // public static class Deserialize
+
+        /// <summary>
+        /// Serialize recursively the instances as XML elements.
+        /// </summary>
+        internal class VisitorWithWriter
+            : Visitation.AbstractVisitorWithContext<Xml.XmlWriter>
+        {
+            /// <summary>
+            /// Write <paramref name="that" /> where <paramref name="writer" /> already
+            /// is.
+            /// </summary>
+            /// <remarks>
+            /// Every value is written through this one shape, so that the writing can
+            /// be composed: a <c>Write*</c> combinator turns a stringification, a list
+            /// or a tuple of them into one of these, and a class's own
+            /// <c>...ToSequence</c> already is one.
+            ///
+            /// There is deliberately no second delegate for a whole element: an element
+            /// differs from a content only in what it writes, never in its shape, and
+            /// <c>WrapInElement</c> converts between the two.
+            ///
+            /// <typeparamref name="T" /> is contravariant, so that
+            /// <see cref="WriteIClass" /> can be used wherever the writer of a more
+            /// specific interface is expected.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value to write</typeparam>
+            private delegate void ContentWriter<in T>(
+                T that,
+                Xml.XmlWriter writer);
+
+            /// <summary>
+            /// Write <paramref name="that" /> as an XML element named
+            /// <paramref name="elementName" />, its content written by
+            /// <paramref name="writeContent" />.
+            /// </summary>
+            /// <remarks>
+            /// An element is nothing but a start and an end tag around a content, so
+            /// there is no writer per property kind -- only the content differs, and it
+            /// has been composed once into a field.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value to write</typeparam>
+            private static void WriteElement<T>(
+                string elementName,
+                T that,
+                Xml.XmlWriter writer,
+                ContentWriter<T> writeContent)
+            {
+                writer.WriteStartElement(elementName, NS);
+                writeContent(that, writer);
+                writer.WriteEndElement();
+            }
+
+            /// <summary>
+            /// Write the property <paramref name="propertyName" /> of the instance being
+            /// serialized as an XML element named <paramref name="elementName" />.
+            /// </summary>
+            /// <remarks>
+            /// This is <see cref="WriteElement{T}" /> plus the one segment of the path
+            /// which only the property knows. The path names the C# property, and not
+            /// the XML element: a serialization error is reported on an <em>instance</em>,
+            /// which the caller holds, and not on a document which has not been written
+            /// yet.
+            /// </remarks>
+            /// <typeparam name="T">Type of the value to write</typeparam>
+            private static void WriteProperty<T>(
+                string elementName,
+                string propertyName,
+                T that,
+                Xml.XmlWriter writer,
+                ContentWriter<T> writeContent)
+            {
+                try
+                {
+                    WriteElement(elementName, that, writer, writeContent);
+                }
+                catch (SerializationFailure failure)
+                {
+                    failure.Error.PrependSegment(
+                        new Reporting.NameSegment(propertyName));
+                    throw;
+                }
+            }
+
+            /// <summary>
+            /// Write the items of a list, each with <paramref name="writeItem" />.
+            /// </summary>
+            /// <remarks>
+            /// An empty list writes no items at all, which the reading sees as
+            /// a self-closing element.
+            /// </remarks>
+            /// <typeparam name="T">Type of a single list item</typeparam>
+            private static ContentWriter<List<T>> WriteList<T>(
+                ContentWriter<T> writeItem
+                )
+            {
+                return (that, writer) =>
+                {
+                    int index = 0;
+                    foreach (var item in that)
+                    {
+                        try
+                        {
+                            writeItem(item, writer);
+                        }
+                        catch (SerializationFailure failure)
+                        {
+                            failure.Error.PrependSegment(
+                                new Reporting.IndexSegment(index));
+                            throw;
+                        }
+                        index++;
+                    }
+                };
+            }
+
+            /// <summary>
+            /// The one instance through which the writing is dispatched.
+            /// </summary>
+            /// <remarks>
+            /// The visitor carries no state -- the writer is passed in as the context --
+            /// so a single instance serves the whole program. No field initializer reads
+            /// it, only <see cref="WriteIClass" /> does, so it does not matter where
+            /// among the writers it is initialized.
+            /// </remarks>
+            [CodeAnalysis.SuppressMessage("ReSharper", "InconsistentNaming")]
+            private static readonly VisitorWithWriter _instance = (
+                new VisitorWithWriter());
+
+            /// <summary>
+            /// Write <paramref name="that" /> as its own XML element.
+            /// </summary>
+            /// <remarks>
+            /// Which element that is, is decided by the run-time type of
+            /// <paramref name="that" />, so this one writer serves every abstract class
+            /// and every concrete class with descendants, as well as the item of a list
+            /// or of a tuple of any of them.
+            /// </remarks>
+            internal static void WriteIClass(
+                Our.IClass that,
+                Xml.XmlWriter writer)
+            {
+                that.Accept(_instance, writer);
+            }
+
+            private static readonly ContentWriter<string> Write_string = (
+                (that, writer) => writer.WriteValue(that));
+
+            private static readonly ContentWriter<long> Write_long = (
+                (that, writer) => writer.WriteValue(that));
+
+            private static readonly ContentWriter<List<IItem>> Write_ListOf_IItem = (
+                WriteList<IItem>(
+                    WriteIClass));
+
+            private static readonly ContentWriter<List<ISomeItem>> Write_ListOf_ISomeItem = (
+                WriteList<ISomeItem>(
+                    WriteIClass));
+
+            private static readonly ContentWriter<List<ISpecialItem>> Write_ListOf_ISpecialItem = (
+                WriteList<ISpecialItem>(
+                    WriteIClass));
+
+            private static readonly ContentWriter<IContainer> Write_IContainer = (
+                ContainerToSequence);
+
+            private static void SomeItemToSequence(
+                Our.ISomeItem that,
+                Xml.XmlWriter writer)
+            {
+                WriteProperty(
+                    "name", "Name", that.Name, writer, Write_string);
+
+                if (that.Nickname != null)
+                {
+                    WriteProperty(
+                        "nickname", "Nickname", that.Nickname, writer, Write_string);
+                }
+            }  // private static void SomeItemToSequence
+
+            public override void VisitSomeItem(
+                Our.ISomeItem that,
+                Xml.XmlWriter writer)
+            {
+                writer.WriteStartElement(
+                    "someItem",
+                    NS);
+                SomeItemToSequence(
+                    that,
+                    writer);
+                writer.WriteEndElement();
+            }
+
+            private static void SpecialItemToSequence(
+                Our.ISpecialItem that,
+                Xml.XmlWriter writer)
+            {
+                WriteProperty(
+                    "name", "Name", that.Name, writer, Write_string);
+
+                if (that.Nickname != null)
+                {
+                    WriteProperty(
+                        "nickname", "Nickname", that.Nickname, writer, Write_string);
+                }
+
+                WriteProperty(
+                    "level", "Level", that.Level, writer, Write_long);
+            }  // private static void SpecialItemToSequence
+
+            public override void VisitSpecialItem(
+                Our.ISpecialItem that,
+                Xml.XmlWriter writer)
+            {
+                writer.WriteStartElement(
+                    "specialItem",
+                    NS);
+                SpecialItemToSequence(
+                    that,
+                    writer);
+                writer.WriteEndElement();
+            }
+
+            private static void ContainerToSequence(
+                Our.IContainer that,
+                Xml.XmlWriter writer)
+            {
+                WriteProperty(
+                    "items", "Items", that.Items, writer, Write_ListOf_IItem);
+
+                WriteProperty(
+                    "someItems", "SomeItems", that.SomeItems, writer, Write_ListOf_ISomeItem);
+
+                if (that.SpecialItems != null)
+                {
+                    WriteProperty(
+                        "specialItems",
+                        "SpecialItems",
+                        that.SpecialItems,
+                        writer,
+                        Write_ListOf_ISpecialItem);
+                }
+            }  // private static void ContainerToSequence
+
+            public override void VisitContainer(
+                Our.IContainer that,
+                Xml.XmlWriter writer)
+            {
+                writer.WriteStartElement(
+                    "container",
+                    NS);
+                ContainerToSequence(
+                    that,
+                    writer);
+                writer.WriteEndElement();
+            }
+
+            private static void WrapperToSequence(
+                Our.IWrapper that,
+                Xml.XmlWriter writer)
+            {
+                WriteProperty(
+                    "container", "Container", that.Container, writer, Write_IContainer);
+            }  // private static void WrapperToSequence
+
+            public override void VisitWrapper(
+                Our.IWrapper that,
+                Xml.XmlWriter writer)
+            {
+                writer.WriteStartElement(
+                    "wrapper",
+                    NS);
+                WrapperToSequence(
+                    that,
+                    writer);
+                writer.WriteEndElement();
+            }
+        }  // internal class VisitorWithWriter
+
+        /// <summary>
+        /// Serialize instances of meta-model classes to XML.
+        /// </summary>
+        /// <example>
+        /// Here is an example how to serialize an instance of IItem:
+        /// <code>
+        /// var anInstance = new Our.IItem(
+        ///     /* ... some constructor arguments ... */
+        /// );
+        /// var writer = new System.Xml.XmlWriter( /* some arguments */ );
+        /// Serialize.To(
+        ///     anInstance,
+        ///     writer);
+        /// </code>
+        /// </example>
+        public static class Serialize
+        {
+            /// <summary>
+            /// Serialize an instance of the meta-model to XML.
+            /// </summary>
+            /// <exception cref="SerializationException">
+            /// Thrown when a value within <paramref name="that" /> instance can not be
+            /// represented in XML
+            /// </exception>
+            public static void To(
+                Our.IClass that,
+                Xml.XmlWriter writer)
+            {
+                try
+                {
+                    VisitorWithWriter.WriteIClass(
+                        that, writer);
+                }
+                catch (SerializationFailure failure)
+                {
+                    throw new SerializationException(
+                        Reporting.GenerateCSharpPath(failure.Error.PathSegments),
+                        failure.Error.Cause);
+                }
+            }
+        }  // public static class Serialize
+    }  // public static class Xmlization
+}  // namespace dummy
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/csharp/expected/variance_of_containers/input/snippets/namespace.txt b/dev/test_data/main/csharp/expected/variance_of_containers/input/snippets/namespace.txt
new file mode 100644
index 000000000..2995a4d0e
--- /dev/null
+++ b/dev/test_data/main/csharp/expected/variance_of_containers/input/snippets/namespace.txt
@@ -0,0 +1 @@
+dummy
\ No newline at end of file
diff --git a/dev/test_data/main/golang/expected/aas_core_meta.v3/expected_output/common/common.go b/dev/test_data/main/golang/expected/aas_core_meta.v3/expected_output/common/common.go
index aef908bbd..740dbbbf3 100644
--- a/dev/test_data/main/golang/expected/aas_core_meta.v3/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/aas_core_meta.v3/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/annotated_assignments/expected_output/common/common.go b/dev/test_data/main/golang/expected/annotated_assignments/expected_output/common/common.go
index 384cf6ed6..3038f3a94 100644
--- a/dev/test_data/main/golang/expected/annotated_assignments/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/annotated_assignments/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/annotated_assignments/expected_output/verification/verification.go b/dev/test_data/main/golang/expected/annotated_assignments/expected_output/verification/verification.go
index 1b6343cee..8e0dcd8cb 100644
--- a/dev/test_data/main/golang/expected/annotated_assignments/expected_output/verification/verification.go
+++ b/dev/test_data/main/golang/expected/annotated_assignments/expected_output/verification/verification.go
@@ -47,13 +47,15 @@ func (ve *VerificationError) PathString() string {
 }
 
 // Check an optional class declared with `None` and assigned in a loop.
-func FirstChildAIsSmall(
-	parents []ourtypes.IParent,
+//
+// The items of the argument parents are of the type parameter ParentsT instead of ourtypes.IParent so that the slices of the descendants of ourtypes.IParent can be passed without a copy, as the slices are invariant in Go.
+func FirstChildAIsSmall[ParentsT ourtypes.IParent](
+	parents []ParentsT,
 ) bool {
 	var found ourtypes.IChildA = nil
 	for _, parent := range parents {
 		if ourtypes.IsChildA(parent) {
-			found = parent.(ourtypes.IChildA)
+			found = any(parent).(ourtypes.IChildA)
 			break
 		}
 	}
@@ -89,9 +91,11 @@ func TextIsAllowedUnlessLong(
 }
 
 // Check a non-optional variable declared wider than its value.
-func LastChildBIsNotZero(
+//
+// The items of the argument parents are of the type parameter ParentsT instead of ourtypes.IParent so that the slices of the descendants of ourtypes.IParent can be passed without a copy, as the slices are invariant in Go.
+func LastChildBIsNotZero[ParentsT ourtypes.IParent](
 	parent ourtypes.IParent,
-	parents []ourtypes.IParent,
+	parents []ParentsT,
 ) bool {
 	var last ourtypes.IParent = parent
 	for _, other := range parents {
diff --git a/dev/test_data/main/golang/expected/arithmetic/expected_output/common/common.go b/dev/test_data/main/golang/expected/arithmetic/expected_output/common/common.go
index 3eed0b382..96220fbeb 100644
--- a/dev/test_data/main/golang/expected/arithmetic/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/arithmetic/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/assert_statements/expected_output/common/common.go b/dev/test_data/main/golang/expected/assert_statements/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/assert_statements/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/assert_statements/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/assignment_targets/expected_output/common/common.go b/dev/test_data/main/golang/expected/assignment_targets/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/assignment_targets/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/assignment_targets/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/collections_in_returns/expected_output/common/common.go b/dev/test_data/main/golang/expected/collections_in_returns/expected_output/common/common.go
index e830e0e1d..9645e4de3 100644
--- a/dev/test_data/main/golang/expected/collections_in_returns/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/collections_in_returns/expected_output/common/common.go
@@ -40,6 +40,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/constrained_primitives/expected_output/common/common.go b/dev/test_data/main/golang/expected/constrained_primitives/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/constrained_primitives/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/constrained_primitives/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/custom_serialization_names/expected_output/common/common.go b/dev/test_data/main/golang/expected/custom_serialization_names/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/custom_serialization_names/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/custom_serialization_names/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/deep_class_hierarchy/expected_output/common/common.go b/dev/test_data/main/golang/expected/deep_class_hierarchy/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/deep_class_hierarchy/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/deep_class_hierarchy/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/empty_class/expected_output/common/common.go b/dev/test_data/main/golang/expected/empty_class/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/empty_class/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/empty_class/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/enum/expected_output/common/common.go b/dev/test_data/main/golang/expected/enum/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/enum/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/enum/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/float_only/expected_output/common/common.go b/dev/test_data/main/golang/expected/float_only/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/float_only/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/float_only/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/for_statements/expected_output/common/common.go b/dev/test_data/main/golang/expected/for_statements/expected_output/common/common.go
index a93f333f5..2a89bdda6 100644
--- a/dev/test_data/main/golang/expected/for_statements/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/for_statements/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/if_statements/expected_output/common/common.go b/dev/test_data/main/golang/expected/if_statements/expected_output/common/common.go
index a93f333f5..2a89bdda6 100644
--- a/dev/test_data/main/golang/expected/if_statements/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/if_statements/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/if_statements/expected_output/verification/verification.go b/dev/test_data/main/golang/expected/if_statements/expected_output/verification/verification.go
index e48ed1322..d49772daa 100644
--- a/dev/test_data/main/golang/expected/if_statements/expected_output/verification/verification.go
+++ b/dev/test_data/main/golang/expected/if_statements/expected_output/verification/verification.go
@@ -228,17 +228,19 @@ func NarrowingAfterTheOnlyCompletingBranch(
 }
 
 // Check the narrowing after the `continue` and the early return in a loop.
-func ChildAsHaveTexts(
-	parents []ourtypes.IParent,
+//
+// The items of the argument parents are of the type parameter ParentsT instead of ourtypes.IParent so that the slices of the descendants of ourtypes.IParent can be passed without a copy, as the slices are invariant in Go.
+func ChildAsHaveTexts[ParentsT ourtypes.IParent](
+	parents []ParentsT,
 ) bool {
 	for _, parent := range parents {
 		if !ourtypes.IsChildA(parent) {
 			continue
 		}
-		if parent.(ourtypes.IChildA).OptionalText() == nil {
+		if any(parent).(ourtypes.IChildA).OptionalText() == nil {
 			return false
 		}
-		if ourcommon.LenStr(*parent.(ourtypes.IChildA).OptionalText()) < 1 {
+		if ourcommon.LenStr(*any(parent).(ourtypes.IChildA).OptionalText()) < 1 {
 			return false
 		}
 	}
@@ -246,8 +248,10 @@ func ChildAsHaveTexts(
 }
 
 // Check the narrowing after the `continue` in a loop with a `break`.
-func TextsBeforeContainerAreShort(
-	parents []ourtypes.IParent,
+//
+// The items of the argument parents are of the type parameter ParentsT instead of ourtypes.IParent so that the slices of the descendants of ourtypes.IParent can be passed without a copy, as the slices are invariant in Go.
+func TextsBeforeContainerAreShort[ParentsT ourtypes.IParent](
+	parents []ParentsT,
 ) bool {
 	total := int64(0)
 	for _, parent := range parents {
@@ -275,14 +279,16 @@ func TextOrDefaultIsShort(
 }
 
 // Check the narrowing of a variable to a class by the assigned value.
-func LastChildAIsSmall(
+//
+// The items of the argument parents are of the type parameter ParentsT instead of ourtypes.IParent so that the slices of the descendants of ourtypes.IParent can be passed without a copy, as the slices are invariant in Go.
+func LastChildAIsSmall[ParentsT ourtypes.IParent](
 	parent ourtypes.IParent,
-	parents []ourtypes.IParent,
+	parents []ParentsT,
 ) bool {
 	last := parent
 	for _, other := range parents {
 		if ourtypes.IsChildA(other) {
-			last = other.(ourtypes.IChildA)
+			last = any(other).(ourtypes.IChildA)
 			if last.(ourtypes.IChildA).AOnly() >= 1000 {
 				return false
 			}
diff --git a/dev/test_data/main/golang/expected/implementation_specific/expected_output/common/common.go b/dev/test_data/main/golang/expected/implementation_specific/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/implementation_specific/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/implementation_specific/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/int_length_interplay/expected_output/common/common.go b/dev/test_data/main/golang/expected/int_length_interplay/expected_output/common/common.go
index a93f333f5..2a89bdda6 100644
--- a/dev/test_data/main/golang/expected/int_length_interplay/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/int_length_interplay/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/int_parsing_and_lstrip/expected_output/common/common.go b/dev/test_data/main/golang/expected/int_parsing_and_lstrip/expected_output/common/common.go
index 0a823533a..68ab58f50 100644
--- a/dev/test_data/main/golang/expected/int_parsing_and_lstrip/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/int_parsing_and_lstrip/expected_output/common/common.go
@@ -40,6 +40,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/is_instance/expected_output/common/common.go b/dev/test_data/main/golang/expected/is_instance/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/is_instance/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/is_instance/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/json_types/expected_output/common/common.go b/dev/test_data/main/golang/expected/json_types/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/json_types/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/json_types/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/json_types_in_collections/expected_output/common/common.go b/dev/test_data/main/golang/expected/json_types_in_collections/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/json_types_in_collections/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/json_types_in_collections/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/json_types_in_invariants/expected_output/common/common.go b/dev/test_data/main/golang/expected/json_types_in_invariants/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/json_types_in_invariants/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/json_types_in_invariants/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/list_of_classes/expected_output/common/common.go b/dev/test_data/main/golang/expected/list_of_classes/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/list_of_classes/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/list_of_classes/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/list_of_classes/expected_output/verification/verification.go b/dev/test_data/main/golang/expected/list_of_classes/expected_output/verification/verification.go
index 227c6b0be..c9e62fd42 100644
--- a/dev/test_data/main/golang/expected/list_of_classes/expected_output/verification/verification.go
+++ b/dev/test_data/main/golang/expected/list_of_classes/expected_output/verification/verification.go
@@ -72,13 +72,15 @@ func SimplesWith(
 //
 // The appended items are narrowed down to [ourtypes.ISomeItem], while the list
 // holds [ourtypes.IAbstractItem]'s.
-func SomeItemsOf(
-	items []ourtypes.IAbstractItem,
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IAbstractItem so that the slices of the descendants of ourtypes.IAbstractItem can be passed without a copy, as the slices are invariant in Go.
+func SomeItemsOf[ItemsT ourtypes.IAbstractItem](
+	items []ItemsT,
 ) []ourtypes.IAbstractItem {
 	var result []ourtypes.IAbstractItem = []ourtypes.IAbstractItem{}
 	for _, item := range items {
 		if ourtypes.IsSomeItem(item) {
-			result = append(result, item.(ourtypes.ISomeItem))
+			result = append(result, any(item).(ourtypes.ISomeItem))
 		}
 	}
 	return result
@@ -91,7 +93,7 @@ func IsInSimples(
 	simple ourtypes.ISimple,
 	simples []ourtypes.ISimple,
 ) bool {
-	return ourcommon.SliceContains(
+	return ourcommon.SliceContainsInstance(
 			simples,
 			simple,
 		)
@@ -109,7 +111,7 @@ func IsInLocalCopyOfSimples(
 	for _, other := range simples {
 		copied = append(copied, other)
 	}
-	return ourcommon.SliceContains(
+	return ourcommon.SliceContainsInstance(
 			copied,
 			simple,
 		)
diff --git a/dev/test_data/main/golang/expected/list_of_constrained_primitives/expected_output/common/common.go b/dev/test_data/main/golang/expected/list_of_constrained_primitives/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/list_of_constrained_primitives/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/list_of_constrained_primitives/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/list_of_enums/expected_output/common/common.go b/dev/test_data/main/golang/expected/list_of_enums/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/list_of_enums/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/list_of_enums/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/list_of_primitives/expected_output/common/common.go b/dev/test_data/main/golang/expected/list_of_primitives/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/list_of_primitives/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/list_of_primitives/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/method_references/expected_output/common/common.go b/dev/test_data/main/golang/expected/method_references/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/method_references/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/method_references/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/nested_any_in_all/expected_output/common/common.go b/dev/test_data/main/golang/expected/nested_any_in_all/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/nested_any_in_all/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/nested_any_in_all/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/nested_collections/expected_output/common/common.go b/dev/test_data/main/golang/expected/nested_collections/expected_output/common/common.go
index e830e0e1d..9645e4de3 100644
--- a/dev/test_data/main/golang/expected/nested_collections/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/nested_collections/expected_output/common/common.go
@@ -40,6 +40,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/optional_arguments/expected_output/common/common.go b/dev/test_data/main/golang/expected/optional_arguments/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/optional_arguments/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/optional_arguments/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/primitive_types/expected_output/common/common.go b/dev/test_data/main/golang/expected/primitive_types/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/primitive_types/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/primitive_types/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/problematic_keywords/expected_output/common/common.go b/dev/test_data/main/golang/expected/problematic_keywords/expected_output/common/common.go
index b7b572a16..9cd0eae53 100644
--- a/dev/test_data/main/golang/expected/problematic_keywords/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/problematic_keywords/expected_output/common/common.go
@@ -38,6 +38,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/sets/expected_output/common/common.go b/dev/test_data/main/golang/expected/sets/expected_output/common/common.go
index c395e3d5e..b655a2582 100644
--- a/dev/test_data/main/golang/expected/sets/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/sets/expected_output/common/common.go
@@ -40,6 +40,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/string_slicing_and_find/expected_output/common/common.go b/dev/test_data/main/golang/expected/string_slicing_and_find/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/string_slicing_and_find/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/string_slicing_and_find/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/switch_statements/expected_output/common/common.go b/dev/test_data/main/golang/expected/switch_statements/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/switch_statements/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/switch_statements/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/transpiled_methods/expected_output/common/common.go b/dev/test_data/main/golang/expected/transpiled_methods/expected_output/common/common.go
index 3eed0b382..96220fbeb 100644
--- a/dev/test_data/main/golang/expected/transpiled_methods/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/transpiled_methods/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/tuples/expected_output/common/common.go b/dev/test_data/main/golang/expected/tuples/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/tuples/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/tuples/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/unions/expected_output/common/common.go b/dev/test_data/main/golang/expected/unions/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/unions/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/unions/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/common.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/common.go
new file mode 100644
index 000000000..740dbbbf3
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/common.go
@@ -0,0 +1,350 @@
+// Package common provides common functions shared among the other packages.
+package common
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"strings"
+	"unicode/utf8"
+)
+
+func Concat(
+	parts ...string,
+) string {
+	b := new(strings.Builder)
+	for _, part := range parts {
+		b.WriteString(part)
+	}
+	return b.String()
+}
+
+// Check if the map contains the given key.
+func MapContains[K comparable, V any](m map[K]V, k K) bool {
+	_, ok := m[k]
+	return ok
+}
+
+// Check if the slice contains the given value.
+//
+// We can not use ``slices.Contains`` as it is available only from Go 1.21 on.
+// We compare the values as ``any``'s, since the interfaces, such as our classes,
+// satisfy the constraint ``comparable`` only from Go 1.20 on.
+func SliceContains[T any](s []T, v T) bool {
+	for _, item := range s {
+		if any(item) == any(v) {
+			return true
+		}
+	}
+	return false
+}
+
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
+// Check if any of the elements satisfy the condition.
+func Some[V any](condition func(V) bool, l []V) bool {
+	ok := false
+	for _, v := range l {
+		ok = ok || condition(v)
+	}
+	return ok
+}
+
+// Check if all the elements satisfy the condition.
+func All[V any](condition func(V) bool, l []V) bool {
+	for _, v := range l {
+		if !condition(v) {
+			return false
+		}
+	}
+	return true
+}
+
+// Check if some of the elements in the given range satisfy the condition.
+//
+// The range is over the lengths (`int`) or over the integers (`int64`).
+func SomeRange[T int | int64](condition func(T) bool, start T, end T) bool {
+	for i := start; i < end; i++ {
+		if condition(i) {
+			return true
+		}
+	}
+	return false
+}
+
+// Check if all the elements in the given range satisfy the condition.
+//
+// The range is over the lengths (`int`) or over the integers (`int64`).
+func AllRange[T int | int64](condition func(T) bool, start T, end T) bool {
+	for i := start; i < end; i++ {
+		if !condition(i) {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy the `value` to a new variable, and return the pointer to it.
+//
+// We represent the optional values which are not nilable, such as strings,
+// numbers and enumeration literals, as pointers. Go does not allow to take
+// the address of a literal or of an expression, such as `&"something"`
+// or `&(x + 1)`, so we need a function to hold the value in a variable of its
+// own. Moreover, taking the address of a variable directly, such as `&text`,
+// would alias the variable, so that a later assignment to the variable would
+// also change the value pointed to.
+//
+// Mind that Go infers `int` for an untyped integer constant, so you need to
+// convert it explicitly, for example, `NewAndPointTo(int64(1))`.
+func NewAndPointTo[T any](value T) *T {
+	return &value
+}
+
+// Represent a fixed-size heterogeneous tuple of 1 item(s).
+type Tuple1[T1 any] struct {
+	Item1 T1
+}
+
+// Count the items of the tuple.
+func (tuple Tuple1[T1]) Len() int {
+	return 1
+}
+
+// Represent a fixed-size heterogeneous tuple of 2 item(s).
+type Tuple2[T1 any, T2 any] struct {
+	Item1 T1
+	Item2 T2
+}
+
+// Count the items of the tuple.
+func (tuple Tuple2[T1, T2]) Len() int {
+	return 2
+}
+
+// Represent a fixed-size heterogeneous tuple of 3 item(s).
+type Tuple3[T1 any, T2 any, T3 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+}
+
+// Count the items of the tuple.
+func (tuple Tuple3[T1, T2, T3]) Len() int {
+	return 3
+}
+
+// Represent a fixed-size heterogeneous tuple of 4 item(s).
+type Tuple4[T1 any, T2 any, T3 any, T4 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+	Item4 T4
+}
+
+// Count the items of the tuple.
+func (tuple Tuple4[T1, T2, T3, T4]) Len() int {
+	return 4
+}
+
+// Represent a fixed-size heterogeneous tuple of 5 item(s).
+type Tuple5[T1 any, T2 any, T3 any, T4 any, T5 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+	Item4 T4
+	Item5 T5
+}
+
+// Count the items of the tuple.
+func (tuple Tuple5[T1, T2, T3, T4, T5]) Len() int {
+	return 5
+}
+
+// Represent a fixed-size heterogeneous tuple of 6 item(s).
+type Tuple6[T1 any, T2 any, T3 any, T4 any, T5 any, T6 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+	Item4 T4
+	Item5 T5
+	Item6 T6
+}
+
+// Count the items of the tuple.
+func (tuple Tuple6[T1, T2, T3, T4, T5, T6]) Len() int {
+	return 6
+}
+
+// Represent a fixed-size heterogeneous tuple of 7 item(s).
+type Tuple7[T1 any, T2 any, T3 any, T4 any, T5 any, T6 any, T7 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+	Item4 T4
+	Item5 T5
+	Item6 T6
+	Item7 T7
+}
+
+// Count the items of the tuple.
+func (tuple Tuple7[T1, T2, T3, T4, T5, T6, T7]) Len() int {
+	return 7
+}
+
+// Represent a fixed-size heterogeneous tuple of 8 item(s).
+type Tuple8[T1 any, T2 any, T3 any, T4 any, T5 any, T6 any, T7 any, T8 any] struct {
+	Item1 T1
+	Item2 T2
+	Item3 T3
+	Item4 T4
+	Item5 T5
+	Item6 T6
+	Item7 T7
+	Item8 T8
+}
+
+// Count the items of the tuple.
+func (tuple Tuple8[T1, T2, T3, T4, T5, T6, T7, T8]) Len() int {
+	return 8
+}
+
+// Resolve `position` in a string of `length` as Python does in slicing.
+//
+// A negative position counts from the end, and the positions out of range are
+// clamped to the string.
+func resolvePosition(position int64, length int) int {
+	if position < 0 {
+		position += int64(length)
+		if position < 0 {
+			return 0
+		}
+		return int(position)
+	}
+
+	if position > int64(length) {
+		return length
+	}
+	return int(position)
+}
+
+// Compute the byte offset of the character at `position` in `text`.
+//
+// The `position` counts the characters (code points), and must not exceed
+// the number of characters in `text`.
+func byteOffsetOf(text string, position int) int {
+	count := 0
+	for offset := range text {
+		if count == position {
+			return offset
+		}
+		count++
+	}
+	return len(text)
+}
+
+// Count the characters (code points) of `text`.
+//
+// We follow the Python implementation of `len`, since Python is the language of
+// the meta-model specifications. Hence, we count the characters instead of
+// the UTF-8 bytes as the native `len` does.
+func LenStr(text string) int {
+	return utf8.RuneCountInString(text)
+}
+
+// Slice `text` from `start` up to `end`, exclusive.
+//
+// We follow the Python implementation of slicing, since Python is
+// the language of the meta-model specifications. Hence, the positions count
+// the characters (code points), a negative position counts from the end,
+// the positions out of range are clamped to the string, and the slice is empty
+// if `start` is not before `end`.
+func SliceStr(text string, start int64, end int64) string {
+	length := LenStr(text)
+	theStart := resolvePosition(start, length)
+	theEnd := resolvePosition(end, length)
+
+	if theStart >= theEnd {
+		return ""
+	}
+
+	return text[byteOffsetOf(text, theStart):byteOffsetOf(text, theEnd)]
+}
+
+// Slice `text` from `start` up to its end.
+//
+// See [SliceStr] for the semantics.
+func SliceStrFrom(text string, start int64) string {
+	theStart := resolvePosition(start, LenStr(text))
+	return text[byteOffsetOf(text, theStart):]
+}
+
+// Find the first `sub` in `text` from `start` on.
+//
+// Return the position of `sub` in `text`, or -1 if `sub` could not be found.
+//
+// We follow the Python implementation of `str.find`, since Python is
+// the language of the meta-model specifications. Hence, the positions count
+// the characters (code points), a negative `start` counts from the end, and
+// a `start` beyond the end of `text` gives -1.
+func FindStr(text string, sub string, start int64) int64 {
+	length := int64(LenStr(text))
+	if start < 0 {
+		start += length
+		if start < 0 {
+			start = 0
+		}
+	}
+
+	if start > length {
+		return -1
+	}
+
+	startOffset := byteOffsetOf(text, int(start))
+	index := strings.Index(text[startOffset:], sub)
+	if index == -1 {
+		return -1
+	}
+
+	return start + int64(LenStr(text[startOffset:startOffset+index]))
+}
+
+// Check if any of the items of the set satisfy the condition.
+//
+// The set is represented as a map to empty structs.
+func SomeKey[K comparable](condition func(K) bool, set map[K]struct{}) bool {
+	for k := range set {
+		if condition(k) {
+			return true
+		}
+	}
+	return false
+}
+
+// Check if all the items of the set satisfy the condition.
+//
+// The set is represented as a map to empty structs.
+func AllKeys[K comparable](condition func(K) bool, set map[K]struct{}) bool {
+	for k := range set {
+		if !condition(k) {
+			return false
+		}
+	}
+	return true
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/string_helpers_test/string_helpers_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/string_helpers_test/string_helpers_test.go
new file mode 100644
index 000000000..a7cf7f4cc
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/common/string_helpers_test/string_helpers_test.go
@@ -0,0 +1,347 @@
+// Test `len`, the slicing of strings and `find` as used in the transpiled code.
+//
+// The transpiled code follows the Python implementation, since Python is
+// the language of the meta-model specifications. Hence, the lengths and
+// the positions count the characters (code points). The expected values have
+// been computed with Python, and all the SDKs test against the very same cases.
+package common_string_helpers_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"testing"
+	ourcommon "github.com/dummy-works/dummy/common"
+)
+
+func TestLenEmptyText(t *testing.T) {
+	got := ourcommon.LenStr("")
+	if got != 0 {
+		t.Errorf("Expected len('') to give 0 (empty text), but got %d", got)
+	}
+}
+
+func TestLenAsciiText(t *testing.T) {
+	got := ourcommon.LenStr("abc")
+	if got != 3 {
+		t.Errorf("Expected len('abc') to give 3 (ASCII text), but got %d", got)
+	}
+}
+
+func TestLenCharacterOfTwoUtf8Bytes(t *testing.T) {
+	got := ourcommon.LenStr("é-")
+	if got != 2 {
+		t.Errorf("Expected len('é-') to give 2 (character of two UTF-8 bytes), but got %d", got)
+	}
+}
+
+func TestLenCharacterBeyondTheBasicMultilingualPlane(t *testing.T) {
+	got := ourcommon.LenStr("\U0001f600-")
+	if got != 2 {
+		t.Errorf("Expected len('\U0001f600-') to give 2 (character beyond the Basic Multilingual Plane), but got %d", got)
+	}
+}
+
+func TestLenMixedCharacters(t *testing.T) {
+	got := ourcommon.LenStr("aé\U0001f600b\U0001f600")
+	if got != 5 {
+		t.Errorf("Expected len('aé\U0001f600b\U0001f600') to give 5 (mixed characters), but got %d", got)
+	}
+}
+
+func TestSliceStartAndEnd(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 1, 3)
+	if got != "bc" {
+		t.Errorf("Expected 'abcde'[1:3] to give 'bc' (start and end), but got %q", got)
+	}
+}
+
+func TestSliceNoStart(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 0, 2)
+	if got != "ab" {
+		t.Errorf("Expected 'abcde'[:2] to give 'ab' (no start), but got %q", got)
+	}
+}
+
+func TestSliceNoEnd(t *testing.T) {
+	got := ourcommon.SliceStrFrom("abcde", 3)
+	if got != "de" {
+		t.Errorf("Expected 'abcde'[3:] to give 'de' (no end), but got %q", got)
+	}
+}
+
+func TestSliceNeitherStartNorEnd(t *testing.T) {
+	got := ourcommon.SliceStrFrom("abcde", 0)
+	if got != "abcde" {
+		t.Errorf("Expected 'abcde'[:] to give 'abcde' (neither start nor end), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartCountsFromTheEnd(t *testing.T) {
+	got := ourcommon.SliceStrFrom("abcde", -2)
+	if got != "de" {
+		t.Errorf("Expected 'abcde'[-2:] to give 'de' (negative start counts from the end), but got %q", got)
+	}
+}
+
+func TestSliceNegativeEndCountsFromTheEnd(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 0, -2)
+	if got != "abc" {
+		t.Errorf("Expected 'abcde'[:-2] to give 'abc' (negative end counts from the end), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartAndEnd(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", -4, -1)
+	if got != "bcd" {
+		t.Errorf("Expected 'abcde'[-4:-1] to give 'bcd' (negative start and end), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartBeforeTheBeginningIsClamped(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", -10, 2)
+	if got != "ab" {
+		t.Errorf("Expected 'abcde'[-10:2] to give 'ab' (negative start before the beginning is clamped), but got %q", got)
+	}
+}
+
+func TestSliceEndBeyondTheEndIsClamped(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 2, 10)
+	if got != "cde" {
+		t.Errorf("Expected 'abcde'[2:10] to give 'cde' (end beyond the end is clamped), but got %q", got)
+	}
+}
+
+func TestSliceStartBeyondTheEndGivesEmpty(t *testing.T) {
+	got := ourcommon.SliceStrFrom("abcde", 10)
+	if got != "" {
+		t.Errorf("Expected 'abcde'[10:] to give '' (start beyond the end gives empty), but got %q", got)
+	}
+}
+
+func TestSliceStartAfterEndGivesEmpty(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 3, 1)
+	if got != "" {
+		t.Errorf("Expected 'abcde'[3:1] to give '' (start after end gives empty), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartAfterNegativeEndGivesEmpty(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", -1, -3)
+	if got != "" {
+		t.Errorf("Expected 'abcde'[-1:-3] to give '' (negative start after negative end gives empty), but got %q", got)
+	}
+}
+
+func TestSliceStartEqualToEndGivesEmpty(t *testing.T) {
+	got := ourcommon.SliceStr("abcde", 5, 5)
+	if got != "" {
+		t.Errorf("Expected 'abcde'[5:5] to give '' (start equal to end gives empty), but got %q", got)
+	}
+}
+
+func TestSliceEmptyText(t *testing.T) {
+	got := ourcommon.SliceStr("", 0, 0)
+	if got != "" {
+		t.Errorf("Expected ''[0:0] to give '' (empty text), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartOnEmptyText(t *testing.T) {
+	got := ourcommon.SliceStrFrom("", -1)
+	if got != "" {
+		t.Errorf("Expected ''[-1:] to give '' (negative start on empty text), but got %q", got)
+	}
+}
+
+func TestSliceEndBeyondTheEndOfEmptyText(t *testing.T) {
+	got := ourcommon.SliceStr("", 0, 5)
+	if got != "" {
+		t.Errorf("Expected ''[:5] to give '' (end beyond the end of empty text), but got %q", got)
+	}
+}
+
+func TestSliceAfterACharacterOfTwoUtf8Bytes(t *testing.T) {
+	got := ourcommon.SliceStrFrom("é-x", 1)
+	if got != "-x" {
+		t.Errorf("Expected 'é-x'[1:] to give '-x' (after a character of two UTF-8 bytes), but got %q", got)
+	}
+}
+
+func TestSliceCharacterOfTwoUtf8Bytes(t *testing.T) {
+	got := ourcommon.SliceStr("aéb", 1, 2)
+	if got != "é" {
+		t.Errorf("Expected 'aéb'[1:2] to give 'é' (character of two UTF-8 bytes), but got %q", got)
+	}
+}
+
+func TestSliceCharacterBeyondTheBasicMultilingualPlane(t *testing.T) {
+	got := ourcommon.SliceStr("a\U0001f600b", 1, 2)
+	if got != "\U0001f600" {
+		t.Errorf("Expected 'a\U0001f600b'[1:2] to give '\U0001f600' (character beyond the Basic Multilingual Plane), but got %q", got)
+	}
+}
+
+func TestSliceAfterACharacterBeyondTheBasicMultilingualPlane(t *testing.T) {
+	got := ourcommon.SliceStrFrom("\U0001f600-x", 1)
+	if got != "-x" {
+		t.Errorf("Expected '\U0001f600-x'[1:] to give '-x' (after a character beyond the Basic Multilingual Plane), but got %q", got)
+	}
+}
+
+func TestSliceNegativeStartOnCharactersBeyondAscii(t *testing.T) {
+	got := ourcommon.SliceStr("aé\U0001f600b\U0001f600", -3, -1)
+	if got != "\U0001f600b" {
+		t.Errorf("Expected 'aé\U0001f600b\U0001f600'[-3:-1] to give '\U0001f600b' (negative start on characters beyond ASCII), but got %q", got)
+	}
+}
+
+func TestFindFound(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "b", 0)
+	if got != 1 {
+		t.Errorf("Expected 'abcabc'.find('b') to give 1 (found), but got %d", got)
+	}
+}
+
+func TestFindNotFound(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "x", 0)
+	if got != -1 {
+		t.Errorf("Expected 'abcabc'.find('x') to give -1 (not found), but got %d", got)
+	}
+}
+
+func TestFindEmptySub(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "", 0)
+	if got != 0 {
+		t.Errorf("Expected 'abcabc'.find('') to give 0 (empty sub), but got %d", got)
+	}
+}
+
+func TestFindSubLongerThanText(t *testing.T) {
+	got := ourcommon.FindStr("ab", "abc", 0)
+	if got != -1 {
+		t.Errorf("Expected 'ab'.find('abc') to give -1 (sub longer than text), but got %d", got)
+	}
+}
+
+func TestFindFoundAfterStart(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "b", 2)
+	if got != 4 {
+		t.Errorf("Expected 'abcabc'.find('b', 2) to give 4 (found after start), but got %d", got)
+	}
+}
+
+func TestFindFoundOnlyBeforeStart(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "b", 5)
+	if got != -1 {
+		t.Errorf("Expected 'abcabc'.find('b', 5) to give -1 (found only before start), but got %d", got)
+	}
+}
+
+func TestFindNegativeStartCountsFromTheEnd(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "c", -1)
+	if got != 5 {
+		t.Errorf("Expected 'abcabc'.find('c', -1) to give 5 (negative start counts from the end), but got %d", got)
+	}
+}
+
+func TestFindNegativeStartFindsTheLaterOccurrence(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "a", -3)
+	if got != 3 {
+		t.Errorf("Expected 'abcabc'.find('a', -3) to give 3 (negative start finds the later occurrence), but got %d", got)
+	}
+}
+
+func TestFindNegativeStartBeforeTheBeginningIsClamped(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "a", -10)
+	if got != 0 {
+		t.Errorf("Expected 'abcabc'.find('a', -10) to give 0 (negative start before the beginning is clamped), but got %d", got)
+	}
+}
+
+func TestFindEmptySubAtTheEnd(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "", 6)
+	if got != 6 {
+		t.Errorf("Expected 'abcabc'.find('', 6) to give 6 (empty sub at the end), but got %d", got)
+	}
+}
+
+func TestFindEmptySubBeyondTheEndGives1(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "", 7)
+	if got != -1 {
+		t.Errorf("Expected 'abcabc'.find('', 7) to give -1 (empty sub beyond the end gives -1), but got %d", got)
+	}
+}
+
+func TestFindStartBeyondTheEndGives1(t *testing.T) {
+	got := ourcommon.FindStr("abcabc", "c", 10)
+	if got != -1 {
+		t.Errorf("Expected 'abcabc'.find('c', 10) to give -1 (start beyond the end gives -1), but got %d", got)
+	}
+}
+
+func TestFindEmptySubInEmptyText(t *testing.T) {
+	got := ourcommon.FindStr("", "", 0)
+	if got != 0 {
+		t.Errorf("Expected ''.find('') to give 0 (empty sub in empty text), but got %d", got)
+	}
+}
+
+func TestFindEmptySubBeyondTheEndOfEmptyTextGives1(t *testing.T) {
+	got := ourcommon.FindStr("", "", 1)
+	if got != -1 {
+		t.Errorf("Expected ''.find('', 1) to give -1 (empty sub beyond the end of empty text gives -1), but got %d", got)
+	}
+}
+
+func TestFindNotFoundInEmptyText(t *testing.T) {
+	got := ourcommon.FindStr("", "x", 0)
+	if got != -1 {
+		t.Errorf("Expected ''.find('x') to give -1 (not found in empty text), but got %d", got)
+	}
+}
+
+func TestFindAfterACharacterOfTwoUtf8Bytes(t *testing.T) {
+	got := ourcommon.FindStr("é-", "-", 0)
+	if got != 1 {
+		t.Errorf("Expected 'é-'.find('-') to give 1 (after a character of two UTF-8 bytes), but got %d", got)
+	}
+}
+
+func TestFindAfterACharacterBeyondTheBasicMultilingualPlane(t *testing.T) {
+	got := ourcommon.FindStr("\U0001f600-", "-", 0)
+	if got != 1 {
+		t.Errorf("Expected '\U0001f600-'.find('-') to give 1 (after a character beyond the Basic Multilingual Plane), but got %d", got)
+	}
+}
+
+func TestFindCharacterBeyondTheBasicMultilingualPlane(t *testing.T) {
+	got := ourcommon.FindStr("a\U0001f600b", "\U0001f600", 0)
+	if got != 1 {
+		t.Errorf("Expected 'a\U0001f600b'.find('\U0001f600') to give 1 (character beyond the Basic Multilingual Plane), but got %d", got)
+	}
+}
+
+func TestFindStartAfterACharacterBeyondAscii(t *testing.T) {
+	got := ourcommon.FindStr("\U0001f600a\U0001f600a", "a", 2)
+	if got != 3 {
+		t.Errorf("Expected '\U0001f600a\U0001f600a'.find('a', 2) to give 3 (start after a character beyond ASCII), but got %d", got)
+	}
+}
+
+func TestFindNegativeStartOnCharactersBeyondAscii(t *testing.T) {
+	got := ourcommon.FindStr("\U0001f600a\U0001f600a", "\U0001f600", -2)
+	if got != 2 {
+		t.Errorf("Expected '\U0001f600a\U0001f600a'.find('\U0001f600', -2) to give 2 (negative start on characters beyond ASCII), but got %d", got)
+	}
+}
+
+func TestFindStartBeyondTheEndOfCharactersBeyondAscii(t *testing.T) {
+	got := ourcommon.FindStr("é\U0001f600", "", 3)
+	if got != -1 {
+		t.Errorf("Expected 'é\U0001f600'.find('', 3) to give -1 (start beyond the end of characters beyond ASCII), but got %d", got)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/constants/constants.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/constants/constants.go
new file mode 100644
index 000000000..7b3022602
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/constants/constants.go
@@ -0,0 +1,11 @@
+// Package constants provides immutable values of the meta-model.
+//
+// These are not necessarily constants in the sense of Go language, but
+// variables that are expected not to be mutated by the clients.
+package constants
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/enhancing.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/enhancing.go
new file mode 100644
index 000000000..9f4b9a4c1
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/enhancing.go
@@ -0,0 +1,478 @@
+// Package enhancing allows for enhancement of model instances with your custom data.
+package enhancing
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+type enhanced[E any] interface {
+	// Get the enhancement from the enhanced instance.
+	getEnhancement() E
+
+	// Set the enhancement of the enhanced instance.
+	setEnhancement(E)
+}
+
+type enhancedSomeItem[E any] struct {
+	instance ourtypes.ISomeItem
+	enhancement E
+}
+
+func (esi *enhancedSomeItem[E]) ModelType(
+) ourtypes.ModelType {
+	return esi.instance.ModelType()
+}
+
+func (esi *enhancedSomeItem[E]) DescendOnce(
+	action func(ourtypes.IClass)bool,
+) bool {
+	return esi.instance.DescendOnce(action)
+}
+
+func (esi *enhancedSomeItem[E]) Descend(
+	action func(ourtypes.IClass) bool,
+) bool {
+	return esi.instance.Descend(action)
+}
+
+func (esi *enhancedSomeItem[E]) Name(
+) string {
+	return esi.instance.Name()
+}
+
+func (esi *enhancedSomeItem[E]) SetName(
+	value string,
+) {
+	esi.instance.SetName(value)
+}
+
+func (esi *enhancedSomeItem[E]) Nickname(
+) *string {
+	return esi.instance.Nickname()
+}
+
+func (esi *enhancedSomeItem[E]) SetNickname(
+	value *string,
+) {
+	esi.instance.SetNickname(value)
+}
+
+func (esi *enhancedSomeItem[E]) getEnhancement(
+) E {
+	return esi.enhancement
+}
+
+func (esi *enhancedSomeItem[E]) setEnhancement(
+	value E,
+) {
+	esi.enhancement = value
+}
+
+func wrapSomeItem[E any](
+	that ourtypes.ISomeItem,
+	factory func(ourtypes.IClass) (E, bool),
+) (result ourtypes.ISomeItem) {
+	// We assume that we already checked whether `that` has been enhanced
+	// in the caller.
+
+	enh, shouldEnhance := factory(that)
+	if shouldEnhance {
+		result = &enhancedSomeItem[E]{
+			instance: that,
+			enhancement: enh,
+		}
+	} else {
+		result = that
+	}
+
+	return
+}
+
+type enhancedSpecialItem[E any] struct {
+	instance ourtypes.ISpecialItem
+	enhancement E
+}
+
+func (esi *enhancedSpecialItem[E]) ModelType(
+) ourtypes.ModelType {
+	return esi.instance.ModelType()
+}
+
+func (esi *enhancedSpecialItem[E]) DescendOnce(
+	action func(ourtypes.IClass)bool,
+) bool {
+	return esi.instance.DescendOnce(action)
+}
+
+func (esi *enhancedSpecialItem[E]) Descend(
+	action func(ourtypes.IClass) bool,
+) bool {
+	return esi.instance.Descend(action)
+}
+
+func (esi *enhancedSpecialItem[E]) Name(
+) string {
+	return esi.instance.Name()
+}
+
+func (esi *enhancedSpecialItem[E]) SetName(
+	value string,
+) {
+	esi.instance.SetName(value)
+}
+
+func (esi *enhancedSpecialItem[E]) Nickname(
+) *string {
+	return esi.instance.Nickname()
+}
+
+func (esi *enhancedSpecialItem[E]) SetNickname(
+	value *string,
+) {
+	esi.instance.SetNickname(value)
+}
+
+func (esi *enhancedSpecialItem[E]) Level(
+) int64 {
+	return esi.instance.Level()
+}
+
+func (esi *enhancedSpecialItem[E]) SetLevel(
+	value int64,
+) {
+	esi.instance.SetLevel(value)
+}
+
+func (esi *enhancedSpecialItem[E]) getEnhancement(
+) E {
+	return esi.enhancement
+}
+
+func (esi *enhancedSpecialItem[E]) setEnhancement(
+	value E,
+) {
+	esi.enhancement = value
+}
+
+func wrapSpecialItem[E any](
+	that ourtypes.ISpecialItem,
+	factory func(ourtypes.IClass) (E, bool),
+) (result ourtypes.ISpecialItem) {
+	// We assume that we already checked whether `that` has been enhanced
+	// in the caller.
+
+	enh, shouldEnhance := factory(that)
+	if shouldEnhance {
+		result = &enhancedSpecialItem[E]{
+			instance: that,
+			enhancement: enh,
+		}
+	} else {
+		result = that
+	}
+
+	return
+}
+
+type enhancedContainer[E any] struct {
+	instance ourtypes.IContainer
+	enhancement E
+}
+
+func (ec *enhancedContainer[E]) ModelType(
+) ourtypes.ModelType {
+	return ec.instance.ModelType()
+}
+
+func (ec *enhancedContainer[E]) DescendOnce(
+	action func(ourtypes.IClass)bool,
+) bool {
+	return ec.instance.DescendOnce(action)
+}
+
+func (ec *enhancedContainer[E]) Descend(
+	action func(ourtypes.IClass) bool,
+) bool {
+	return ec.instance.Descend(action)
+}
+
+func (ec *enhancedContainer[E]) Items(
+) []ourtypes.IItem {
+	return ec.instance.Items()
+}
+
+func (ec *enhancedContainer[E]) SetItems(
+	value []ourtypes.IItem,
+) {
+	ec.instance.SetItems(value)
+}
+
+func (ec *enhancedContainer[E]) SomeItems(
+) []ourtypes.ISomeItem {
+	return ec.instance.SomeItems()
+}
+
+func (ec *enhancedContainer[E]) SetSomeItems(
+	value []ourtypes.ISomeItem,
+) {
+	ec.instance.SetSomeItems(value)
+}
+
+func (ec *enhancedContainer[E]) SpecialItems(
+) []ourtypes.ISpecialItem {
+	return ec.instance.SpecialItems()
+}
+
+func (ec *enhancedContainer[E]) SetSpecialItems(
+	value []ourtypes.ISpecialItem,
+) {
+	ec.instance.SetSpecialItems(value)
+}
+
+func (c *enhancedContainer[E]) CountItems(
+	items []ourtypes.IItem,
+) int64 {
+	return c.instance.CountItems(
+		items,
+	)
+}
+
+func (ec *enhancedContainer[E]) getEnhancement(
+) E {
+	return ec.enhancement
+}
+
+func (ec *enhancedContainer[E]) setEnhancement(
+	value E,
+) {
+	ec.enhancement = value
+}
+
+func wrapContainer[E any](
+	that ourtypes.IContainer,
+	factory func(ourtypes.IClass) (E, bool),
+) (result ourtypes.IContainer) {
+	// We assume that we already checked whether `that` has been enhanced
+	// in the caller.
+
+	enh, shouldEnhance := factory(that)
+	if shouldEnhance {
+		result = &enhancedContainer[E]{
+			instance: that,
+			enhancement: enh,
+		}
+	} else {
+		result = that
+	}
+
+	wrap_ListOf_IItem_inPlace[E](that.Items(), factory)
+
+	wrap_ListOf_ISomeItem_inPlace[E](that.SomeItems(), factory)
+
+	theSpecialItems := that.SpecialItems()
+	if theSpecialItems != nil {
+		wrap_ListOf_ISpecialItem_inPlace[E](theSpecialItems, factory)
+	}
+
+	return
+}
+
+type enhancedWrapper[E any] struct {
+	instance ourtypes.IWrapper
+	enhancement E
+}
+
+func (ew *enhancedWrapper[E]) ModelType(
+) ourtypes.ModelType {
+	return ew.instance.ModelType()
+}
+
+func (ew *enhancedWrapper[E]) DescendOnce(
+	action func(ourtypes.IClass)bool,
+) bool {
+	return ew.instance.DescendOnce(action)
+}
+
+func (ew *enhancedWrapper[E]) Descend(
+	action func(ourtypes.IClass) bool,
+) bool {
+	return ew.instance.Descend(action)
+}
+
+func (ew *enhancedWrapper[E]) Container(
+) ourtypes.IContainer {
+	return ew.instance.Container()
+}
+
+func (ew *enhancedWrapper[E]) SetContainer(
+	value ourtypes.IContainer,
+) {
+	ew.instance.SetContainer(value)
+}
+
+func (ew *enhancedWrapper[E]) getEnhancement(
+) E {
+	return ew.enhancement
+}
+
+func (ew *enhancedWrapper[E]) setEnhancement(
+	value E,
+) {
+	ew.enhancement = value
+}
+
+func wrapWrapper[E any](
+	that ourtypes.IWrapper,
+	factory func(ourtypes.IClass) (E, bool),
+) (result ourtypes.IWrapper) {
+	// We assume that we already checked whether `that` has been enhanced
+	// in the caller.
+
+	enh, shouldEnhance := factory(that)
+	if shouldEnhance {
+		result = &enhancedWrapper[E]{
+			instance: that,
+			enhancement: enh,
+		}
+	} else {
+		result = that
+	}
+
+	that.SetContainer(
+		wrapClass[E](that.Container(), factory),
+	)
+
+	return
+}
+
+// Wrap `that` instance recursively with the enhancement produced by
+// the `factory`, and keep its static type.
+func wrapClass[E any, T ourtypes.IClass](
+	that T,
+	factory func(ourtypes.IClass) (E, bool),
+) T {
+	return Wrap[E](that, factory).(T)
+}
+
+// Wrap recursively the instances held by `that` in-situ.
+func wrap_ListOf_IItem_inPlace[E any](
+	that []ourtypes.IItem,
+	factory func(ourtypes.IClass) (E, bool),
+) {
+	for i := range that {
+		that[i] = wrapClass[E](that[i], factory)
+	}
+}
+
+// Wrap recursively the instances held by `that` in-situ.
+func wrap_ListOf_ISomeItem_inPlace[E any](
+	that []ourtypes.ISomeItem,
+	factory func(ourtypes.IClass) (E, bool),
+) {
+	for i := range that {
+		that[i] = wrapClass[E](that[i], factory)
+	}
+}
+
+// Wrap recursively the instances held by `that` in-situ.
+func wrap_ListOf_ISpecialItem_inPlace[E any](
+	that []ourtypes.ISpecialItem,
+	factory func(ourtypes.IClass) (E, bool),
+) {
+	for i := range that {
+		that[i] = wrapClass[E](that[i], factory)
+	}
+}
+
+// Wrap `that` instance recursively with the enhancement produced by the `factory`.
+//
+// The factory returns the enhancement, and a boolean "should-enhance". If
+// the "should-enhance" is false, `that` instance is not enhance, and we simply
+// return it. However, we will still continue to enhance the instances referenced
+// by `that` instance recursively.
+//
+// If `that` instance has been already wrapped, panic.
+func Wrap[E any](
+	that ourtypes.IClass,
+	factory func(ourtypes.IClass) (E, bool),
+) (result ourtypes.IClass) {
+	_, ok := that.(enhanced[E])
+	if ok {
+		panic(
+			fmt.Sprintf(
+				"An instance of %T has been already wrapped: %v",
+				that, that,
+			),
+		)
+	}
+
+	switch that.ModelType() {
+	case ourtypes.ModelTypeSomeItem:
+		result = wrapSomeItem[E](
+			that.(ourtypes.ISomeItem),
+			factory,
+		)
+	case ourtypes.ModelTypeSpecialItem:
+		result = wrapSpecialItem[E](
+			that.(ourtypes.ISpecialItem),
+			factory,
+		)
+	case ourtypes.ModelTypeContainer:
+		result = wrapContainer[E](
+			that.(ourtypes.IContainer),
+			factory,
+		)
+	case ourtypes.ModelTypeWrapper:
+		result = wrapWrapper[E](
+			that.(ourtypes.IWrapper),
+			factory,
+		)
+	default:
+		panic(
+			fmt.Sprintf(
+				"Unexpected model type: %v",
+				that.ModelType(),
+			),
+		)
+	}
+
+	return
+}
+
+// Retrieve the enhancement from `that` instance.
+//
+// Return the enhancement, or `ok` false, if `that` instance has not been
+// enhanced.
+func Unwrap[E any](that ourtypes.IClass) (enhancement E, ok bool) {
+	var enh enhanced[E]
+	enh, ok = that.(enhanced[E])
+	if !ok {
+		return
+	}
+	enhancement = enh.getEnhancement()
+	return
+}
+
+// Retrieve the enhancement from `that` instance.
+//
+// If `that` instance has not been enhanced yet, panic.
+func MustUnwrap[E any](that ourtypes.IClass) (enhancement E) {
+	var ok bool
+	enhancement, ok = Unwrap[E](that)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"An instance of %T has not been wrapped: %v",
+				that, that,
+			),
+		)
+	}
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/test/enhancing_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/test/enhancing_test.go
new file mode 100644
index 000000000..074966dec
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/enhancing/test/enhancing_test.go
@@ -0,0 +1,295 @@
+package enhancing_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"testing"
+	ourenhancing "github.com/dummy-works/dummy/enhancing"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+type Enhancement struct {
+	ID int
+}
+
+func collectIDsAndAssertTheyAreConsecutiveAndTheirCountEqualsNextID(
+	t *testing.T,
+	wrapped ourtypes.IClass,
+	nextID int,
+) {
+	var ids []int
+
+	instanceEnh := ourenhancing.MustUnwrap[*Enhancement](wrapped)
+	ids = append(ids, instanceEnh.ID)
+
+	wrapped.Descend(
+		func(that ourtypes.IClass) (abort bool) {
+			enh := ourenhancing.MustUnwrap[*Enhancement](that)
+			ids = append(ids, enh.ID)
+			return
+		},
+	)
+
+	if len(ids) != nextID {
+		t.Fatalf("Expected to collect %d IDs, but got: %d", len(ids), nextID)
+		return
+	}
+
+	for i, id := range ids {
+		if id != i {
+			t.Fatalf(
+				"Unexpected ID at index %d (starting from 0); expected %d, got %d",
+				i, i, id,
+			)
+		}
+	}
+}
+
+func TestSomeItemWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalSomeItem()
+
+	nextID := 0
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			enh = &Enhancement{}
+			enh.ID = nextID
+			should = true
+
+			nextID++
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	collectIDsAndAssertTheyAreConsecutiveAndTheirCountEqualsNextID(
+		t, wrapped, nextID,
+	)
+}
+
+func TestSomeItemNothingWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalSomeItem()
+
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			should = false
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	// Wrapped should be equal to instance by reference as our enhancement factory
+	// did not wrap anything.
+	if wrapped != instance {
+		t.Fatalf("Unexpected inequality between %v and %v", wrapped, instance)
+	}
+
+	wrapped.Descend(func (that ourtypes.IClass) (abort bool) {
+		_, ok := ourenhancing.Unwrap[*Enhancement](that)
+		if ok {
+			t.Fatalf("Unexpected wrapped descendant: %v", that)
+		}
+		return
+	})
+}
+
+func TestSpecialItemWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalSpecialItem()
+
+	nextID := 0
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			enh = &Enhancement{}
+			enh.ID = nextID
+			should = true
+
+			nextID++
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	collectIDsAndAssertTheyAreConsecutiveAndTheirCountEqualsNextID(
+		t, wrapped, nextID,
+	)
+}
+
+func TestSpecialItemNothingWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalSpecialItem()
+
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			should = false
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	// Wrapped should be equal to instance by reference as our enhancement factory
+	// did not wrap anything.
+	if wrapped != instance {
+		t.Fatalf("Unexpected inequality between %v and %v", wrapped, instance)
+	}
+
+	wrapped.Descend(func (that ourtypes.IClass) (abort bool) {
+		_, ok := ourenhancing.Unwrap[*Enhancement](that)
+		if ok {
+			t.Fatalf("Unexpected wrapped descendant: %v", that)
+		}
+		return
+	})
+}
+
+func TestContainerWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalContainer()
+
+	nextID := 0
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			enh = &Enhancement{}
+			enh.ID = nextID
+			should = true
+
+			nextID++
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	collectIDsAndAssertTheyAreConsecutiveAndTheirCountEqualsNextID(
+		t, wrapped, nextID,
+	)
+}
+
+func TestContainerNothingWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalContainer()
+
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			should = false
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	// Wrapped should be equal to instance by reference as our enhancement factory
+	// did not wrap anything.
+	if wrapped != instance {
+		t.Fatalf("Unexpected inequality between %v and %v", wrapped, instance)
+	}
+
+	wrapped.Descend(func (that ourtypes.IClass) (abort bool) {
+		_, ok := ourenhancing.Unwrap[*Enhancement](that)
+		if ok {
+			t.Fatalf("Unexpected wrapped descendant: %v", that)
+		}
+		return
+	})
+}
+
+func TestWrapperWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalWrapper()
+
+	nextID := 0
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			enh = &Enhancement{}
+			enh.ID = nextID
+			should = true
+
+			nextID++
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	collectIDsAndAssertTheyAreConsecutiveAndTheirCountEqualsNextID(
+		t, wrapped, nextID,
+	)
+}
+
+func TestWrapperNothingWrapped(t *testing.T) {
+	instance := ourtesting.MustLoadMaximalWrapper()
+
+	wrapped := ourenhancing.Wrap[*Enhancement](
+		instance,
+		func(that ourtypes.IClass) (enh *Enhancement, should bool) {
+			should = false
+			return
+		},
+	)
+
+	if !ourtesting.DeepEqual(instance, wrapped) {
+		t.Fatalf(
+			"Deep equality failed between the instance and the wrapped: %v %v",
+			instance, wrapped,
+		)
+	}
+
+	// Wrapped should be equal to instance by reference as our enhancement factory
+	// did not wrap anything.
+	if wrapped != instance {
+		t.Fatalf("Unexpected inequality between %v and %v", wrapped, instance)
+	}
+
+	wrapped.Descend(func (that ourtypes.IClass) (abort bool) {
+		_, ok := ourenhancing.Unwrap[*Enhancement](that)
+		if ok {
+			t.Fatalf("Unexpected wrapped descendant: %v", that)
+		}
+		return
+	})
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/internal/xmlcommon/xmlcommon.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/internal/xmlcommon/xmlcommon.go
new file mode 100644
index 000000000..436dbd116
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/internal/xmlcommon/xmlcommon.go
@@ -0,0 +1,1062 @@
+// Package xmlcommon provides the XML primitives shared by the de/serialization.
+//
+// The xmlization reads and writes the elements of our own classes, and
+// the xmlrpc package the elements within a JSON-able value. The whitespace
+// skipping, the namespace checks and the framing of an element are the same
+// for both, and live here.
+package xmlcommon
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	b64 "encoding/base64"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+	"unicode"
+	ourcommon "github.com/dummy-works/dummy/common"
+	ourreporting "github.com/dummy-works/dummy/reporting"
+)
+
+// Namespace is the XML namespace in which all the elements of a document live.
+//
+// The elements of the XML-RPC subset, over which a JSON-able value is
+// de/serialized, are the one exception: they live in no namespace at all.
+const Namespace = "https://dummy.com"
+
+// Represent an error during the de-serialization.
+//
+// Implements `error`.
+type DeserializationError struct{
+	Path *ourreporting.Path
+	Message string
+}
+
+func NewDeserializationError(message string) *DeserializationError {
+	return &DeserializationError{
+		Path: &ourreporting.Path{},
+		Message: message,
+	}
+}
+
+func (de *DeserializationError) Error() string {
+	return fmt.Sprintf(
+		"%s: %s",
+		de.PathString(),
+		de.Message,
+	)
+}
+
+// Render the path as a string.
+func (de *DeserializationError) PathString() string {
+	return ourreporting.ToRelativeXPath(de.Path)
+}
+
+// Prepend the element with the `name` to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) PrependName(
+	name string,
+) *DeserializationError {
+	de.Path.PrependName(
+		&ourreporting.NameSegment{Name: name},
+	)
+	return de
+}
+
+// Prepend the element at the `index` to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) PrependIndex(
+	index int,
+) *DeserializationError {
+	de.Path.PrependIndex(
+		&ourreporting.IndexSegment{Index: index},
+	)
+	return de
+}
+
+// Prepend the member with the `key` to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) PrependKey(
+	key string,
+) *DeserializationError {
+	de.Path.PrependKey(
+		&ourreporting.KeySegment{Key: key},
+	)
+	return de
+}
+
+// Cast `err` to a de-serialization error, or panic.
+//
+// Every error which the de-serialization raises is
+// a [DeserializationError], so the cast can only fail on an error which came
+// from somewhere else entirely.
+func MustDeserializationError(err error) *DeserializationError {
+	deseriaErr, ok := err.(*DeserializationError)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected a *DeserializationError, but got %T: %v",
+				err, err,
+			),
+		)
+	}
+	return deseriaErr
+}
+
+// Represent an error during the serialization.
+//
+// Implements `error`.
+type SerializationError struct {
+	Path    *ourreporting.Path
+	Message string
+}
+
+func NewSerializationError(message string) *SerializationError {
+	return &SerializationError{
+		Path:    &ourreporting.Path{},
+		Message: message,
+	}
+}
+
+func (se *SerializationError) Error() string {
+	return fmt.Sprintf(
+		"%s: %s",
+		se.PathString(),
+		se.Message,
+	)
+}
+
+// Render the path as a string.
+func (se *SerializationError) PathString() string {
+	return ourreporting.ToGolangPath(se.Path)
+}
+
+// Prepend the item at the `index` to the path, and return the error back
+// for chaining.
+func (se *SerializationError) PrependIndex(
+	index int,
+) *SerializationError {
+	se.Path.PrependIndex(
+		&ourreporting.IndexSegment{Index: index},
+	)
+	return se
+}
+
+// Prepend the member with the `key` to the path, and return the error back
+// for chaining.
+func (se *SerializationError) PrependKey(
+	key string,
+) *SerializationError {
+	se.Path.PrependKey(
+		&ourreporting.KeySegment{Key: key},
+	)
+	return se
+}
+
+// Cast `err` to a serialization error, or panic.
+//
+// See the note on [MustDeserializationError].
+func MustSerializationError(err error) *SerializationError {
+	seriaErr, ok := err.(*SerializationError)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected a *SerializationError, but got %T: %v",
+				err, err,
+			),
+		)
+	}
+	return seriaErr
+}
+
+// Represent a sentinel token which signals the end-of-file.
+type Eof struct{}
+
+// Check if the string `s` consists only of whitespace.
+//
+// An empty string causes panic — please cover that case before.
+func IsWhitespace(s string) bool {
+	if len(s) == 0 {
+		panic("Unexpected empty string")
+	}
+	for _, c := range s {
+		if !unicode.IsSpace(c) {
+			return false
+		}
+	}
+	return true
+}
+
+// Read the next token from the `decoder` given the `current` token.
+//
+// If `current` token is [Eof], return [Eof].
+func ReadNext(decoder *xml.Decoder, current xml.Token) (next xml.Token, err error) {
+	if _, isEOF := current.(Eof); isEOF {
+		next = current
+		return
+	}
+
+	var tokenErr error
+	next, tokenErr = decoder.Token()
+	if tokenErr != nil {
+		if tokenErr == io.EOF {
+			next = &Eof{}
+			return
+		}
+
+		err = tokenErr
+		return
+	}
+
+	return
+}
+
+// Read all the possible whitespace and comments.
+//
+// Return the `next` token which is neither empty text, nor whitespace nor comment,
+// or [Eof], if we reached the end-of-file.
+//
+// If we already reached the end-of-file, simply return [Eof].
+func SkipEmptyTextWhitespaceAndComments(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (next xml.Token, err error) {
+	stop := false
+	for !stop {
+		if _, isEOF := current.(Eof); isEOF {
+			break
+		}
+
+		switch et := current.(type) {
+		case xml.CharData:
+			text := string(et)
+			if len(text) != 0 && !IsWhitespace(text) {
+				stop = true
+			} else {
+				// We should proceed to the next token.
+			}
+		case xml.Comment:
+			// We should proceed to the next token.
+		default:
+			stop = true
+		}
+
+		if !stop {
+			current, err = ReadNext(decoder, current)
+			if err != nil {
+				return
+			}
+		}
+	}
+
+	next = current
+	return
+}
+
+// Consume the text tokens (char data).
+//
+// Any comment tokens are skipped.
+//
+// Match a run of the four characters which XML calls whitespace.
+var whitespaceRunRe = regexp.MustCompile("[ \t\n\r]+")
+
+// Normalize `text` the way `whiteSpace="collapse"` prescribes.
+//
+// Every atomic XSD type except a string, and every type derived from one by
+// restriction, fixes `whiteSpace` to `collapse`, and a schema author can not
+// change it. A tab, a line feed and a carriage return each become a space,
+// a run of spaces becomes one space, and the leading and trailing spaces go.
+// Only the result of that is a lexical representation to be matched.
+//
+// Mind that this strips only the whitespace *around* the value: a space
+// within it survives as a single space, so "2  3" becomes "2 3", which is
+// still no number.
+//
+// See: https://www.w3.org/TR/xmlschema-2/#rf-whiteSpace
+func CollapseWhitespace(text string) string {
+	return strings.Trim(whitespaceRunRe.ReplaceAllString(text, " "), " ")
+}
+
+// Tell whether `text` is a lexical form of `xs:base64Binary`.
+//
+// The whitespace is expected to be gone already. What is left has to match
+// `(B64 B64 B64 B64)* ((B64 B64 B64 B64) | (B64 B64 B16 "=") | (B64 B04 "=="))?`
+// -- a length which is a multiple of four, the alphabet and nothing else,
+// an equals sign only at the very end, and, easily missed, a constrained
+// character *before* the padding, as the bits which the padding drops have to
+// be zero.
+//
+// The decoders do not agree on any of this, so every target does the same
+// check of its own and refuses the same texts.
+//
+// See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+func matchesXsBase64Binary(text string) bool {
+	if len(text)%4 != 0 {
+		return false
+	}
+
+	if len(text) == 0 {
+		return true
+	}
+
+	pads := 0
+	if text[len(text)-1] == '=' {
+		pads = 1
+		if text[len(text)-2] == '=' {
+			pads = 2
+		}
+	}
+
+	for i := 0; i < len(text)-pads; i++ {
+		character := text[i]
+		inAlphabet := (character >= 'A' && character <= 'Z') ||
+			(character >= 'a' && character <= 'z') ||
+			(character >= '0' && character <= '9') ||
+			character == '+' ||
+			character == '/'
+		if !inAlphabet {
+			return false
+		}
+	}
+
+	// NOTE:
+	// Only these sixteen characters leave the two dropped bits at zero, and
+	// only these four leave the four dropped bits at zero.
+	if pads == 1 {
+		return strings.IndexByte("AEIMQUYcgkosw048", text[len(text)-2]) >= 0
+	}
+
+	if pads == 2 {
+		return strings.IndexByte("AQgw", text[len(text)-3]) >= 0
+	}
+
+	return true
+}
+
+// Drop every whitespace character of `text`.
+//
+// This is what `xs:base64Binary` needs: it allows whitespace between
+// the characters and not only around them, so collapsing is not enough --
+// the decoder accepts none of it.
+func RemoveWhitespace(text string) string {
+	return whitespaceRunRe.ReplaceAllString(text, "")
+}
+
+// The resulting `next` token points to the first token which is neither text
+// nor comment.
+//
+// If we reached the end-of-file, `next` is an [Eof] sentinel token.
+func ReadText(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (text string, next xml.Token, err error) {
+	b := &strings.Builder{}
+
+	stop := false
+	for {
+		if _, isEOF := current.(Eof); isEOF {
+			err = NewDeserializationError(
+				"Expected to read text, but reached the end-of-file",
+			)
+			return
+		}
+
+		switch et := current.(type) {
+		case xml.CharData:
+			b.WriteString(string(et))
+			// Proceed to the next token.
+		case xml.Comment:
+			// Proceed to the next token.
+		default:
+			stop = true
+		}
+
+		if !stop {
+			current, err = ReadNext(decoder, current)
+			if err != nil {
+				return
+			}
+		} else {
+			break
+		}
+	}
+
+	next = current
+	text = b.String()
+	return
+}
+
+// Consume the text tokens (char data) as a representation of a `xs:boolean`.
+//
+// Any comment tokens are skipped.
+//
+// The resulting `next` token points to the first token which is neither text
+// nor comment.
+//
+// If we reached the end-of-file, `next` is an [Eof] sentinel token.
+func ReadTextAs_bool(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (value bool, next xml.Token, err error) {
+	var text string
+	text, next, err = ReadText(decoder, current)
+	if err != nil {
+		return
+	}
+	text = CollapseWhitespace(text)
+
+	switch text {
+	case "1":
+		value = true
+	case "true":
+		value = true
+	case "0":
+		value = false
+	case "false":
+		value = false
+	default:
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected a value as xs:boolean, but got: %s",
+				text,
+			),
+		)
+	}
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// Consume the text tokens (char data) as a representation of a `xs:long`.
+//
+// Any comment tokens are skipped.
+//
+// The resulting `next` token points to the first token which is neither text
+// nor comment.
+//
+// If we reached the end-of-file, `next` is an [Eof] sentinel token.
+func ReadTextAs_long(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (value int64, next xml.Token, err error) {
+	var text string
+	text, next, err = ReadText(decoder, current)
+	if err != nil {
+		return
+	}
+	text = CollapseWhitespace(text)
+
+	var parseErr error
+	value, parseErr = strconv.ParseInt(text, 10, 64)
+	if parseErr != nil {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected a value as xs:long, but it could not be parsed: %s: %s",
+				parseErr.Error(), text,
+			),
+		)
+		return
+	}
+
+	return
+}
+
+func constructXsDoubleRe() *regexp.Regexp {
+	// NOTE:
+	// "+INF" is matched although it is written as "INF": XSD 1.1 admits it,
+	// its production being (\+|-)?INF, and being liberal in what we accept
+	// costs nothing here. strconv.ParseFloat reads it without complaint.
+	doubleRep := "((\\+|-)?([0-9]+(\\.[0-9]*)?|\\.[0-9]+)([Ee](\\+|-)?[0-9]+)?|(\\+|-)?INF|NaN)"
+	pattern := ourcommon.Concat(
+		"^",
+		doubleRep,
+		"$",
+	)
+
+	return regexp.MustCompile(
+		pattern,
+	)
+}
+
+var xsDoubleRe = constructXsDoubleRe()
+
+// Check that text conforms to the pattern of an `xs:double`.
+//
+// See: https://www.w3.org/TR/xmlschema-2/#double
+//
+//   - `text`: Text to be checked
+//   - Return True if the text conforms to the pattern
+func isValidXsDouble(text string) bool {
+	return xsDoubleRe.MatchString(
+		text,
+	)
+}
+
+// Consume the text tokens (char data) as a representation of a `xs:double`.
+//
+// Any comment tokens are skipped.
+//
+// The resulting `next` token points to the first token which is neither text
+// nor comment.
+//
+// If we reached the end-of-file, `next` is an [Eof] sentinel token.
+func ReadTextAs_double(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (value float64, next xml.Token, err error) {
+	var text string
+	text, next, err = ReadText(decoder, current)
+	if err != nil {
+		return
+	}
+	text = CollapseWhitespace(text)
+
+	// We need to check explicitly for the regular expression since
+	// strconv.ParseFloat is too permissive. For example, it accepts "nan"
+	// although only "NaN" is valid.
+	// See: https://www.w3.org/TR/xmlschema-2/#double
+	if !isValidXsDouble(text) {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected a value as xs:double, but got: %s",
+				text,
+			),
+		)
+		return
+	}
+
+	var parseErr error
+	value, parseErr = strconv.ParseFloat(text, 64)
+	// NOTE:
+	// A literal too large for a double is not an error in XSD. It rounds to
+	// an infinity, which is in the value space of xs:double, and ParseFloat
+	// hands us exactly that infinity *together* with [strconv.ErrRange]. So
+	// the range is deliberately let through, and only a syntax error is
+	// reported -- and the pattern above has already excluded those.
+	//
+	// A literal too small rounds to zero, which ParseFloat reports without
+	// any error at all.
+	//
+	// See: https://www.w3.org/TR/xmlschema11-2/#double
+	if parseErr != nil && !errors.Is(parseErr, strconv.ErrRange) {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected a value as xs:double, but it could not be parsed: %s: %s",
+				parseErr.Error(), text,
+			),
+		)
+		return
+	}
+
+	// NOTE:
+	// We explicitly do not check for loss of precision, as the majority of people will
+	// use string representation of the floating point numbers ignoring the precision
+	// issues. For example, the closest double-precision number to the number `359.9` is
+	// `359.8999999999999772626324556767940521240234375`, but most people will simply
+	// give `359.9` as the value.
+
+	return
+}
+
+// Consume the text tokens (char data) as a base64-encoded bytes.
+//
+// Any comment tokens are skipped.
+//
+// The resulting `next` token points to the first token which is neither text
+// nor comment.
+//
+// If we reached the end-of-file, `next` is an [Eof] sentinel token.
+func ReadTextAs_bytes(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (value []byte, next xml.Token, err error) {
+	var text string
+	text, next, err = ReadText(decoder, current)
+	if err != nil {
+		return
+	}
+	// NOTE:
+	// xs:base64Binary allows whitespace between the characters, and not only
+	// around them, while the decoder accepts none of it. So every whitespace
+	// character is dropped, and not merely collapsed.
+	//
+	// See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+	text = RemoveWhitespace(text)
+
+	if !matchesXsBase64Binary(text) {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected a text as base64-encoded bytes, but got: %s",
+				text,
+			),
+		)
+		return
+	}
+
+	var decodingErr error
+	value, decodingErr = b64.StdEncoding.DecodeString(text)
+	if decodingErr != nil {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Text could not be decoded as base64: %s",
+				decodingErr.Error(),
+			),
+		)
+		return
+	}
+
+	return
+}
+
+// Check that the `current` token is a valid start element, *i.e.*, lives in
+// the `ns` namespace and contains no attributes.
+func checkStartElementInNamespace(
+	current xml.StartElement,
+	ns string,
+) (err error) {
+	unexpectedAttr := 0
+	for _, attr := range current.Attr {
+		if (attr.Name.Space == "" && attr.Name.Local == "xmlns") ||
+			attr.Name.Space == "xmlns" {
+			continue
+		}
+
+		unexpectedAttr++
+	}
+	if unexpectedAttr != 0 {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected no attributes except 'xmlns' in the start element, "+
+					"but got %d in the start element %s",
+				unexpectedAttr, current.Name.Local,
+			),
+		)
+		return
+	}
+
+	if current.Name.Space != ns {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected only start elements in the namespace %s, "+
+					"but got a start element %s in the namespace %s",
+				ns, current.Name.Local, current.Name.Space,
+			),
+		)
+		return
+	}
+
+	return
+}
+
+// Expect a valid start element (as defined in [CheckStartElement]) and extract its
+// `local` name.
+//
+// This function is meant to be called whenever you know the runtime type of a token.
+// If you do not know the runtime type, call [ParseAsStartElementAndExtractLocalName]
+// so that you can succinctly check the runtime type as well.
+func extractLocalNameFromStartElementInNamespace(
+	current xml.StartElement,
+	ns string,
+) (local string, err error) {
+	err = checkStartElementInNamespace(current, ns)
+	if err != nil {
+		return
+	}
+
+	local = current.Name.Local
+	return
+}
+
+// Expect a valid start element (as defined in [CheckStartElement]) and extract its
+// local name.
+//
+// Valid means that we check that the start element lives in the `ns` namespace and
+// contains no attributes.
+//
+// If you know the runtime type of `current` token, call
+// [ExtractLocalNameFromStartElement] instead to save a cast.
+func parseAsStartElementAndExtractLocalNameInNamespace(
+	current xml.Token,
+	ns string,
+) (local string, err error) {
+	if _, isEOF := current.(Eof); isEOF {
+		err = NewDeserializationError(
+			"Expected a start element, but reached the end-of-file",
+		)
+		return
+	}
+
+	et, ok := current.(xml.StartElement)
+	if !ok {
+		switch v := current.(type) {
+		case xml.EndElement:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected a start element, but got an end element %s in namespace %s",
+					v.Name.Local, v.Name.Space,
+				),
+			)
+		case xml.CharData:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected a start element, but got text %s",
+					string(v),
+				),
+			)
+		default:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected a start element, but got %T: %v",
+					current, current,
+				),
+			)
+		}
+		return
+	}
+
+	local, err = extractLocalNameFromStartElementInNamespace(et, ns)
+	return
+}
+
+// Check that the `current` token is an end element, living in the `ns` namespace,
+// and having the `local` name.
+func checkEndElementInNamespace(current xml.Token, local string, ns string) (err error) {
+	if _, isEOF := current.(Eof); isEOF {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected an end element %s, but reached the end-of-file",
+				local,
+			),
+		)
+		return
+	}
+
+	et, ok := current.(xml.EndElement)
+	if !ok {
+		switch v := current.(type) {
+		case xml.StartElement:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected an end element %s, but got a start element %s in namespace %s",
+					local, v.Name.Local, v.Name.Space,
+				),
+			)
+		case xml.CharData:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected an end element %s, but got text %s",
+					local, string(v),
+				),
+			)
+		default:
+			err = NewDeserializationError(
+				fmt.Sprintf(
+					"Expected an end element %s, but got %T: %v",
+					local, current, current,
+				),
+			)
+		}
+		return
+	}
+
+	if et.Name.Space != ns {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected an end element %s in the namespace %s, "+
+					"but got an end element in the namespace %s",
+				local, ns, et.Name.Space,
+			),
+		)
+		return
+	}
+
+	if et.Name.Local != local {
+		err = NewDeserializationError(
+			fmt.Sprintf(
+				"Expected an end element %s, but got an end element %s",
+				local, et.Name.Local,
+			),
+		)
+		return
+	}
+
+	return
+}
+
+// Read a value wrapped in a single XML element which lives in the `ns` namespace,
+// dispatching on the local name of that element.
+//
+// The element is read in full: the resulting `next` token points to the first token
+// just after the end element.
+//
+// This is the *only* place which frames an XML element around a value. Every
+// container which reads a sequence of elements delegates the framing here, so
+// that its items differ only in the given `readByLocal`, and never in
+// the container which reads them.
+//
+// `T` is left unconstrained since this function never invokes any method on it.
+// This lets it be reused for an instance, for a scalar and for a JSON-able value
+// alike.
+func readElementDispatchedInNamespace[T any](
+	decoder *xml.Decoder,
+	current xml.Token,
+	ns string,
+	readByLocal func(
+		aDecoder *xml.Decoder,
+		aCurrent xml.Token,
+		aLocal string,
+	) (value T, aNext xml.Token, anErr error),
+) (value T, next xml.Token, err error) {
+	current, err = SkipEmptyTextWhitespaceAndComments(decoder, current)
+	if err != nil {
+		return
+	}
+
+	var local string
+	local, err = parseAsStartElementAndExtractLocalNameInNamespace(current, ns)
+	if err != nil {
+		return
+	}
+
+	// Move the current to the content of the XML element
+	current, err = ReadNext(decoder, current)
+	if err != nil {
+		return
+	}
+
+	value, current, err = readByLocal(decoder, current, local)
+	if err != nil {
+		return
+	}
+
+	err = checkEndElementInNamespace(current, local, ns)
+	if err != nil {
+		return
+	}
+
+	next, err = ReadNext(decoder, current)
+	return
+}
+
+// Check that the `current` token is a valid start element, *i.e.*, lives in
+// the [Namespace] namespace and contains no attributes.
+func CheckStartElement(current xml.StartElement) (err error) {
+	return checkStartElementInNamespace(current, Namespace)
+}
+
+// Extract the local name of the given valid start element, which is expected to
+// live in the [Namespace] namespace.
+func ExtractLocalNameFromStartElement(
+	current xml.StartElement,
+) (local string, err error) {
+	return extractLocalNameFromStartElementInNamespace(current, Namespace)
+}
+
+// Expect a valid start element living in the [Namespace] namespace and extract
+// its local name.
+func ParseAsStartElementAndExtractLocalName(
+	current xml.Token,
+) (local string, err error) {
+	return parseAsStartElementAndExtractLocalNameInNamespace(current, Namespace)
+}
+
+// Check that the `current` token is an end element, living in the [Namespace]
+// namespace, and having the `local` name.
+func CheckEndElement(current xml.Token, local string) (err error) {
+	return checkEndElementInNamespace(current, local, Namespace)
+}
+
+// Read a value wrapped in a single XML element living in the [Namespace]
+// namespace, dispatching on the local name of that element.
+func ReadElementDispatched[T any](
+	decoder *xml.Decoder,
+	current xml.Token,
+	readByLocal func(
+		aDecoder *xml.Decoder,
+		aCurrent xml.Token,
+		aLocal string,
+	) (value T, aNext xml.Token, anErr error),
+) (value T, next xml.Token, err error) {
+	return readElementDispatchedInNamespace(
+		decoder, current, Namespace, readByLocal,
+	)
+}
+
+// Write the start element with the given `local` name to the encoder.
+//
+// Do not flush.
+//
+// If `withNamespace` is set, the element declares [Namespace]. The enclosing
+// element is expected to have declared it otherwise.
+func WriteStartElement(
+	encoder *xml.Encoder,
+	local string,
+	withNamespace bool,
+) (err error) {
+	startElement := xml.StartElement{Name: xml.Name{Local: local}}
+	if withNamespace {
+		startElement.Name.Space = Namespace
+	}
+
+	err = encoder.EncodeToken(startElement)
+	return
+}
+
+// Write the end element with the given `local` name to the encoder.
+//
+// Do not flush.
+//
+// If `withNamespace` is set, the element is spelled in [Namespace], which
+// the corresponding start element has to have declared.
+func WriteEndElement(
+	encoder *xml.Encoder,
+	local string,
+	withNamespace bool,
+) (err error) {
+	endElement := xml.EndElement{Name: xml.Name{Local: local}}
+	if withNamespace {
+		endElement.Name.Space = Namespace
+	}
+
+	err = encoder.EncodeToken(endElement)
+	return
+}
+
+// Write the `text` to the encoder.
+//
+// Do not flush.
+//
+// If `text` is empty, do nothing.
+func WriteText(
+	encoder *xml.Encoder,
+	text string,
+) (err error) {
+	if len(text) > 0 {
+		err = encoder.EncodeToken(
+			xml.CharData([]byte(text)),
+		)
+	}
+	return
+}
+
+// Write the `value` as a `xs:boolean` in a text element.
+//
+// Do not flush.
+func WriteAsText_bool(
+	encoder *xml.Encoder,
+	value bool,
+) (err error) {
+	text := "true"
+	if !value {
+		text = "false"
+	}
+	err = WriteText(encoder, text)
+	return
+}
+
+// Write the `value` as a `xs:long` in a text element.
+//
+// Do not flush.
+func WriteAsText_long(
+	encoder *xml.Encoder,
+	value int64,
+) (err error) {
+	text := strconv.FormatInt(value, 10)
+	err = WriteText(encoder, text)
+	return
+}
+
+// Write the `value` as a `xs:double` in a text element.
+//
+// Do not flush.
+func WriteAsText_double(
+	encoder *xml.Encoder,
+	value float64,
+) (err error) {
+	var text string
+
+	// See: https://www.w3.org/TR/xmlschema-2/#double
+	// for the exact literals.
+	if math.IsInf(value, 0) {
+		if value < 0 {
+			text = "-INF"
+		} else {
+			text = "INF"
+		}
+	} else if math.IsNaN(value) {
+		text = "NaN"
+	} else {
+		text = strconv.FormatFloat(value, 'g', -1, 64)
+	}
+
+	err = WriteText(encoder, text)
+	return
+}
+
+// Write the `value` as a `xs:string` in a text element.
+//
+// Do not flush.
+func WriteAsText_string(
+	encoder *xml.Encoder,
+	value string,
+) (err error) {
+	err = WriteText(encoder, value)
+	return
+}
+
+// Write the `value` as a base64-encoded bytes in a text element.
+//
+// Do not flush.
+func WriteAsText_bytes(
+	encoder *xml.Encoder,
+	value []byte,
+) (err error) {
+	text := b64.StdEncoding.EncodeToString(
+		value,
+	)
+
+	err = WriteText(encoder, text)
+	return
+}
+
+// Write `that` as an XML element with the `local` name, its content written by
+// `writeContent`.
+//
+// Do not flush.
+//
+// This is the one place which frames an XML element around a *value*: a property,
+// a list item, a tuple item and an item of a JSON-able array all go through it,
+// and differ only in the given `writeContent`.
+//
+// The XML namespace is expected to have been defined outside of the resulting XML
+// element.
+func WriteElement[T any](
+	encoder *xml.Encoder,
+	local string,
+	that T,
+	writeContent func(anEncoder *xml.Encoder, aValue T) (anErr error),
+) (err error) {
+	err = WriteStartElement(encoder, local, false)
+	if err != nil {
+		return
+	}
+
+	err = writeContent(encoder, that)
+	if err != nil {
+		return
+	}
+
+	err = WriteEndElement(encoder, local, false)
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/jsonization.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/jsonization.go
new file mode 100644
index 000000000..5e5677859
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/jsonization.go
@@ -0,0 +1,1156 @@
+// Package jsonization de/serializes model instances to and from JSON.
+//
+// We can not use one-pass deserialization for JSON since the object
+// properties do not have fixed order, and hence we can not read
+// `modelType` property ahead of the remaining properties.
+//
+// To de-serialize, call one of the `*FromJsonable` functions.
+//
+// To serialize, call [ToJsonable] function.
+package jsonization
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"math"
+	b64 "encoding/base64"
+	ourreporting "github.com/dummy-works/dummy/reporting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// region De-serialization
+
+// Represent an error during the de-serialization.
+//
+// Implements `error`.
+type DeserializationError struct{
+	Path *ourreporting.Path
+	Message string
+}
+
+func newDeserializationError(message string) *DeserializationError {
+	return &DeserializationError{
+		Path: &ourreporting.Path{},
+		Message: message,
+	}
+}
+
+func (de *DeserializationError) Error() string {
+	return fmt.Sprintf(
+		"%s: %s",
+		de.PathString(),
+		de.Message,
+	)
+}
+
+// Render the path as a string.
+func (de *DeserializationError) PathString() string {
+	return ourreporting.ToJSONPath(de.Path)
+}
+
+// Prepend the `name` segment to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) prependName(
+	name string,
+) *DeserializationError {
+	de.Path.PrependName(
+		&ourreporting.NameSegment{Name: name},
+	)
+	return de
+}
+
+// Prepend the `index` segment to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) prependIndex(
+	index int,
+) *DeserializationError {
+	de.Path.PrependIndex(
+		&ourreporting.IndexSegment{Index: index},
+	)
+	return de
+}
+
+// Prepend the `key` segment to the path, and return the error back
+// for chaining.
+func (de *DeserializationError) prependKey(
+	key string,
+) *DeserializationError {
+	de.Path.PrependKey(
+		&ourreporting.KeySegment{Key: key},
+	)
+	return de
+}
+
+// Cast `err` to a de-serialization error, or panic.
+//
+// Every error which originates in this package is
+// a [DeserializationError], so the cast can only fail if a de-serialization
+// snippet specific to an implementation returned a foreign error.
+func mustDeserializationError(err error) *DeserializationError {
+	deseriaErr, ok := err.(*DeserializationError)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected a *DeserializationError, but got %T: %v",
+				err,
+				err,
+			),
+		)
+	}
+	return deseriaErr
+}
+
+// Parse `jsonable` as a boolean, or return an error.
+func boolFromJsonable(
+	jsonable interface{},
+) (result bool, err error) {
+	if jsonable == nil {
+		err = newDeserializationError(
+			"Expected a boolean, but got null",
+		)
+		return
+	}
+
+	var ok bool
+	result, ok = jsonable.(bool)
+	if !ok {
+		err = newDeserializationError(
+			fmt.Sprintf("Expected a boolean, but got %T", jsonable),
+		)
+
+		return
+	}
+
+	return
+}
+
+// Parse `jsonable` as a 64-bit integer, or return an error.
+func int64FromJsonable(
+	jsonable interface{},
+) (result int64, err error) {
+	if jsonable == nil {
+		err = newDeserializationError(
+			"Expected an integer number, but got null",
+		)
+		return
+	}
+
+	f, ok := jsonable.(float64)
+	if !ok {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected an integer number, but got %T",
+				jsonable,
+			),
+		)
+		return
+	}
+
+	if math.IsNaN(f) {
+		err = newDeserializationError(
+			"Expected an integer number, but got a NaN",
+		)
+		return
+	}
+
+	if math.IsInf(f, 0) {
+		err = newDeserializationError(
+			"Expected an integer number, but got an infinity",
+		)
+		return
+	}
+
+	if f != math.Trunc(f) {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected an integer number, but got a non-integer: %v",
+				f,
+			),
+		)
+		return
+	}
+
+	result = int64(f)
+	if f != float64(result) {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected an integer number fitting into int64, but got: %v",
+				jsonable,
+			),
+		)
+		return
+	}
+
+	return
+}
+
+// Parse `jsonable` as a 64-bit float, or return an error.
+func float64FromJsonable(
+	jsonable interface{},
+) (result float64, err error) {
+	if jsonable == nil {
+		err = newDeserializationError(
+			"Expected a number, but got null",
+		)
+		return
+	}
+
+	var ok bool
+	result, ok = jsonable.(float64)
+	if !ok {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected a number, but got %T",
+				jsonable,
+			),
+		)
+		return
+	}
+
+	// NOTE (mristin):
+	// JSON knows neither an infinity nor a not-a-number, so a conformant parser
+	// can never give us one. The caller can still hand us a JSON-able which has
+	// been constructed programmatically, so we have to check here.
+
+	if math.IsNaN(result) || math.IsInf(result, 0) {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected a finite number, but got: %v",
+				result,
+			),
+		)
+		result = 0
+		return
+	}
+
+	return
+}
+
+// Parse `jsonable` as a string, or return an error.
+func stringFromJsonable(
+	jsonable interface{},
+) (result string, err error) {
+	if jsonable == nil {
+		err = newDeserializationError(
+			"Expected a string, but got null",
+		)
+		return
+	}
+
+	var ok bool
+	result, ok = jsonable.(string)
+	if ok {
+		return
+	} else {
+		err = newDeserializationError(
+			fmt.Sprintf("Expected a string, but got %T", jsonable),
+		)
+		return
+	}
+}
+
+// Parse `jsonable` as a byte array, or return an error.
+func bytesFromJsonable(
+	jsonable interface{},
+) (result []byte, err error) {
+	if jsonable == nil {
+		err = newDeserializationError(
+			"Expected a base64-encoded string, but got null",
+		)
+		return
+	}
+
+	text, ok := jsonable.(string)
+	if !ok {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected a base64-encoded string, but got %T",
+				jsonable,
+			),
+		)
+		return
+	}
+
+	var decodingErr error
+	result, decodingErr = b64.StdEncoding.DecodeString(text)
+	if decodingErr != nil {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"String could not be decoded as base64: %s",
+				decodingErr.Error(),
+			),
+		)
+		return
+	}
+
+	return
+}
+
+// Return a pointer to the `value`, or the `err`, if any.
+//
+// This function takes the *results* of a parse function instead of the parse
+// function itself. Go binds all the results of a call to the whole parameter
+// list of the enclosing call, so this single helper composes with every parse
+// function, however many arguments that function takes -- including
+// `parseOptional(parseTuple2(v, ...))`, which a parser-taking signature could
+// not express, as the item parsers of a tuple vary both in number and in type.
+func parseOptional[T any](value T, err error) (*T, error) {
+	if err != nil {
+		return nil, err
+	}
+	return &value, nil
+}
+
+// Report that `jsonable` is no JSON object.
+func notAMapError(jsonable interface{}) error {
+	if jsonable == nil {
+		return newDeserializationError(
+			"Expected a JSON object, but got null",
+		)
+	}
+
+	return newDeserializationError(
+		fmt.Sprintf(
+			"Expected a JSON object, but got %T",
+			jsonable,
+		),
+	)
+}
+
+// Extract the `modelType` property of `m` as a string, or return an error.
+//
+// This is the only place which knows how the model type is spelled on the wire.
+// Both the dispatch on the model type and its check in a concrete class go
+// through it.
+func modelTypeFromMap(
+	m map[string]interface{},
+) (modelType string, err error) {
+	jsonable, ok := m["modelType"]
+	if !ok {
+		err = newDeserializationError(
+			"The required property modelType is missing",
+		)
+		return
+	}
+
+	modelType, err = stringFromJsonable(jsonable)
+	if err != nil {
+		mustDeserializationError(err).prependName("modelType")
+	}
+	return
+}
+
+// Check that `m` specifies the `expected` model type, or return an error.
+func checkModelType(
+	m map[string]interface{},
+	expected string,
+) (err error) {
+	var modelType string
+	modelType, err = modelTypeFromMap(m)
+	if err != nil {
+		return
+	}
+
+	if modelType != expected {
+		// NOTE (mristin):
+		// A wrong model type is reported at the instance, as an unknown one is,
+		// and as in the other SDKs.
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected the model type '%s', but got %s",
+				expected,
+				modelType,
+			),
+		)
+	}
+	return
+}
+
+// Parse `jsonable` as an array and parse every item with `parseItem`,
+// or return an error.
+func parseArray[T any](
+	jsonable interface{},
+	parseItem func(jsonable interface{}) (T, error),
+) (result []T, err error) {
+	jsonableArray, ok := jsonable.([]interface{})
+	if !ok {
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Expected an array, but got %T",
+				jsonable,
+			),
+		)
+		return
+	}
+
+	result = make([]T, len(jsonableArray))
+	for i, itemJsonable := range jsonableArray {
+		var item T
+		item, err = parseItem(itemJsonable)
+		if err != nil {
+			mustDeserializationError(err).prependIndex(i)
+			return
+		}
+		result[i] = item
+	}
+	return
+}
+
+// Parse `jsonable` as an instance of [ourtypes.IItem],
+// or return an error.
+func ItemFromJsonable(
+	jsonable interface{},
+) (
+	result ourtypes.IItem,
+	err error,
+) {
+	m, ok := jsonable.(map[string]interface{})
+	if !ok {
+		err = notAMapError(jsonable)
+		return
+	}
+
+	return itemFromMap(m)
+}
+
+// Parse `jsonable` as an instance of [ourtypes.ISomeItem],
+// or return an error.
+func SomeItemFromJsonable(
+	jsonable interface{},
+) (
+	result ourtypes.ISomeItem,
+	err error,
+) {
+	m, ok := jsonable.(map[string]interface{})
+	if !ok {
+		err = notAMapError(jsonable)
+		return
+	}
+
+	return someItemFromMap(m)
+}
+
+// Parse [ourtypes.ISomeItem] from a map,
+// or return an error, if any.
+//
+// This function performs no dispatch! It is used to parse the properties
+// as-are, and already assumes the exact model type. Usually, this function
+// is called from within a from-jsonable or from-map function, and you never
+// call it directly. If you want to de-serialize an instance of
+// [ourtypes.ISomeItem], call
+// [SomeItemFromJsonable].
+func someItemFromMapWithoutDispatch(
+	m map[string]interface{},
+) (
+	result ourtypes.ISomeItem,
+	err error,
+) {
+	var theName string
+	var theNickname *string
+
+	foundName := false
+
+	for k, v := range m {
+		switch k {
+		case "name":
+			theName, err = stringFromJsonable(v)
+			foundName = true
+
+		case "nickname":
+			theNickname, err = parseOptional(stringFromJsonable(v))
+
+		case "modelType":
+			// The model type has already been checked before the loop.
+
+		default:
+			err = newDeserializationError(
+				fmt.Sprintf(
+					"Unexpected property: %s",
+					k,
+				),
+			)
+			return
+		}
+
+		if err != nil {
+			mustDeserializationError(err).prependName(k)
+			return
+		}
+	}
+
+	if !foundName {
+		err = newDeserializationError(
+			"The required property 'name' is missing",
+		)
+		return
+	}
+
+	result = ourtypes.NewSomeItem(
+		theName,
+	)
+	result.SetNickname(
+		theNickname,
+	)
+
+	return
+}
+
+// Parse `jsonable` as an instance of [ourtypes.ISpecialItem],
+// or return an error.
+func SpecialItemFromJsonable(
+	jsonable interface{},
+) (
+	result ourtypes.ISpecialItem,
+	err error,
+) {
+	m, ok := jsonable.(map[string]interface{})
+	if !ok {
+		err = notAMapError(jsonable)
+		return
+	}
+
+	err = checkModelType(m, "SpecialItem")
+	if err != nil {
+		return
+	}
+
+	return specialItemFromMapWithoutDispatch(m)
+}
+
+// Parse [ourtypes.ISpecialItem] from a map,
+// or return an error, if any.
+func specialItemFromMapWithoutDispatch(
+	m map[string]interface{},
+) (
+	result ourtypes.ISpecialItem,
+	err error,
+) {
+	var theName string
+	var theNickname *string
+	var theLevel int64
+
+	foundName := false
+	foundLevel := false
+
+	for k, v := range m {
+		switch k {
+		case "name":
+			theName, err = stringFromJsonable(v)
+			foundName = true
+
+		case "nickname":
+			theNickname, err = parseOptional(stringFromJsonable(v))
+
+		case "level":
+			theLevel, err = int64FromJsonable(v)
+			foundLevel = true
+
+		case "modelType":
+			// The model type has already been checked before the loop.
+
+		default:
+			err = newDeserializationError(
+				fmt.Sprintf(
+					"Unexpected property: %s",
+					k,
+				),
+			)
+			return
+		}
+
+		if err != nil {
+			mustDeserializationError(err).prependName(k)
+			return
+		}
+	}
+
+	if !foundName {
+		err = newDeserializationError(
+			"The required property 'name' is missing",
+		)
+		return
+	}
+
+	if !foundLevel {
+		err = newDeserializationError(
+			"The required property 'level' is missing",
+		)
+		return
+	}
+
+	result = ourtypes.NewSpecialItem(
+		theName,
+		theLevel,
+	)
+	result.SetNickname(
+		theNickname,
+	)
+
+	return
+}
+
+// Parse `jsonable` as an instance of [ourtypes.IContainer],
+// or return an error.
+func ContainerFromJsonable(
+	jsonable interface{},
+) (
+	result ourtypes.IContainer,
+	err error,
+) {
+	m, ok := jsonable.(map[string]interface{})
+	if !ok {
+		err = notAMapError(jsonable)
+		return
+	}
+
+	return containerFromMapWithoutDispatch(m)
+}
+
+// Parse [ourtypes.IContainer] from a map,
+// or return an error, if any.
+func containerFromMapWithoutDispatch(
+	m map[string]interface{},
+) (
+	result ourtypes.IContainer,
+	err error,
+) {
+	var theItems []ourtypes.IItem
+	var theSomeItems []ourtypes.ISomeItem
+	var theSpecialItems []ourtypes.ISpecialItem
+
+	foundItems := false
+	foundSomeItems := false
+
+	for k, v := range m {
+		switch k {
+		case "items":
+			theItems, err = parseArray(v, ItemFromJsonable)
+			foundItems = true
+
+		case "someItems":
+			theSomeItems, err = parseArray(v, SomeItemFromJsonable)
+			foundSomeItems = true
+
+		case "specialItems":
+			theSpecialItems, err = parseArray(v, SpecialItemFromJsonable)
+
+		default:
+			err = newDeserializationError(
+				fmt.Sprintf(
+					"Unexpected property: %s",
+					k,
+				),
+			)
+			return
+		}
+
+		if err != nil {
+			mustDeserializationError(err).prependName(k)
+			return
+		}
+	}
+
+	if !foundItems {
+		err = newDeserializationError(
+			"The required property 'items' is missing",
+		)
+		return
+	}
+
+	if !foundSomeItems {
+		err = newDeserializationError(
+			"The required property 'someItems' is missing",
+		)
+		return
+	}
+
+	result = ourtypes.NewContainer(
+		theItems,
+		theSomeItems,
+	)
+	result.SetSpecialItems(
+		theSpecialItems,
+	)
+
+	return
+}
+
+// Parse `jsonable` as an instance of [ourtypes.IWrapper],
+// or return an error.
+func WrapperFromJsonable(
+	jsonable interface{},
+) (
+	result ourtypes.IWrapper,
+	err error,
+) {
+	m, ok := jsonable.(map[string]interface{})
+	if !ok {
+		err = notAMapError(jsonable)
+		return
+	}
+
+	return wrapperFromMapWithoutDispatch(m)
+}
+
+// Parse [ourtypes.IWrapper] from a map,
+// or return an error, if any.
+func wrapperFromMapWithoutDispatch(
+	m map[string]interface{},
+) (
+	result ourtypes.IWrapper,
+	err error,
+) {
+	var theContainer ourtypes.IContainer
+
+	foundContainer := false
+
+	for k, v := range m {
+		switch k {
+		case "container":
+			theContainer, err = ContainerFromJsonable(v)
+			foundContainer = true
+
+		default:
+			err = newDeserializationError(
+				fmt.Sprintf(
+					"Unexpected property: %s",
+					k,
+				),
+			)
+			return
+		}
+
+		if err != nil {
+			mustDeserializationError(err).prependName(k)
+			return
+		}
+	}
+
+	if !foundContainer {
+		err = newDeserializationError(
+			"The required property 'container' is missing",
+		)
+		return
+	}
+
+	result = ourtypes.NewWrapper(
+		theContainer,
+	)
+
+	return
+}
+
+// De-serialize an instance of [ourtypes.IItem]
+// from a map by dispatching to the concrete `*FromMapWithoutDispatch` function.
+func itemFromMap(
+	m map[string]interface{},
+) (
+	result ourtypes.IItem,
+	err error,
+) {
+	var modelType string
+	modelType, err = modelTypeFromMap(m)
+	if err != nil {
+		return
+	}
+
+	switch modelType {
+	case "SomeItem":
+		result, err = someItemFromMapWithoutDispatch(m)
+	case "SpecialItem":
+		result, err = specialItemFromMapWithoutDispatch(m)
+	default:
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Unexpected model type " +
+				"for IItem: %s",
+				modelType,
+			),
+		)
+	}
+
+	return
+}
+
+// De-serialize an instance of [ourtypes.ISomeItem]
+// from a map by dispatching to the concrete `*FromMapWithoutDispatch` function.
+func someItemFromMap(
+	m map[string]interface{},
+) (
+	result ourtypes.ISomeItem,
+	err error,
+) {
+	var modelType string
+	modelType, err = modelTypeFromMap(m)
+	if err != nil {
+		return
+	}
+
+	switch modelType {
+	case "SpecialItem":
+		result, err = specialItemFromMapWithoutDispatch(m)
+	case "SomeItem":
+		result, err = someItemFromMapWithoutDispatch(m)
+	default:
+		err = newDeserializationError(
+			fmt.Sprintf(
+				"Unexpected model type " +
+				"for ISomeItem: %s",
+				modelType,
+			),
+		)
+	}
+
+	return
+}
+
+// endregion
+
+// region Serialization
+
+// Represent an error during the serialization.
+//
+// Implements `error`.
+type SerializationError struct{
+	Path *ourreporting.Path
+	Message string
+}
+
+func newSerializationError(message string) *SerializationError {
+	return &SerializationError{
+		Path: &ourreporting.Path{},
+		Message: message,
+	}
+}
+
+func (se *SerializationError) Error() string {
+	return fmt.Sprintf(
+		"%s: %s",
+		se.PathString(),
+		se.Message,
+	)
+}
+
+// Render the path as a string.
+func (se *SerializationError) PathString() string {
+	return ourreporting.ToGolangPath(se.Path)
+}
+
+// Prepend the `name` segment to the path, and return the error back
+// for chaining.
+func (se *SerializationError) prependName(
+	name string,
+) *SerializationError {
+	se.Path.PrependName(
+		&ourreporting.NameSegment{Name: name},
+	)
+	return se
+}
+
+// Prepend the `index` segment to the path, and return the error back
+// for chaining.
+func (se *SerializationError) prependIndex(
+	index int,
+) *SerializationError {
+	se.Path.PrependIndex(
+		&ourreporting.IndexSegment{Index: index},
+	)
+	return se
+}
+
+// Prepend the `key` segment to the path, and return the error back
+// for chaining.
+func (se *SerializationError) prependKey(
+	key string,
+) *SerializationError {
+	se.Path.PrependKey(
+		&ourreporting.KeySegment{Key: key},
+	)
+	return se
+}
+
+// Cast `err` to a serialization error, or panic.
+//
+// Every error which originates in this package is a [SerializationError],
+// so the cast can only fail if a serialization snippet specific to
+// an implementation returned a foreign error.
+func mustSerializationError(err error) *SerializationError {
+	seriaErr, ok := err.(*SerializationError)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected a *SerializationError, but got %T: %v",
+				err,
+				err,
+			),
+		)
+	}
+	return seriaErr
+}
+
+// Try to cast `that` to a float64 and box it as a JSON-able value, or
+// return an error.
+//
+// The result is returned as `interface{}`, not the more specific
+// `float64`, so that this function itself can be passed on as a bare
+// reference wherever a `func(int64) (interface{}, error)` is expected,
+// e.g. as an item (de)serializer in a list or a tuple.
+func int64ToJsonable(
+	that int64,
+) (result interface{}, err error) {
+	if that > 9007199254740991 || that < -9007199254740991 {
+		err = newSerializationError(
+			fmt.Sprintf(
+				"64-bit integer can not be represented as 64-bit float in JSON: %v",
+				that,
+			),
+		)
+		return
+	}
+
+	result = float64(that);
+	return
+}
+
+// Box `that` as a JSON-able value, or return an error.
+//
+// JSON knows neither an infinity nor a not-a-number, so we refuse to
+// serialize them instead of leaving it to `json.Marshal` to fail much later,
+// with no path to the culprit.
+//
+// The result is returned as `interface{}`, not the more specific
+// `float64`, so that this function itself can be passed on as a bare
+// reference wherever a `func(float64) (interface{}, error)` is expected,
+// e.g. as an item (de)serializer in a list or a tuple.
+func float64ToJsonable(
+	that float64,
+) (result interface{}, err error) {
+	if math.IsNaN(that) {
+		err = newSerializationError(
+			"A not-a-number can not be serialized to JSON",
+		)
+		return
+	}
+
+	if math.IsInf(that, 0) {
+		err = newSerializationError(
+			fmt.Sprintf(
+				"An infinity can not be serialized to JSON: %v",
+				that,
+			),
+		)
+		return
+	}
+
+	result = that
+	return
+}
+
+// Encode `bytes` to a base64 string and box it as a JSON-able value, or
+// return an error.
+//
+// The result is returned as `interface{}`, not the more specific
+// `string`, so that this function itself can be passed on as a bare
+// reference wherever a `func([]byte) (interface{}, error)` is expected,
+// e.g. as an item (de)serializer in a list or a tuple.
+func bytesToJsonable(
+	bytes []byte,
+) (result interface{}, err error) {
+	if bytes == nil {
+		err = newSerializationError(
+			"Expected an array of bytes, but got nil",
+		)
+		return
+	}
+
+	result = b64.StdEncoding.EncodeToString(
+		bytes,
+	)
+	return
+}
+
+// Serialize every item of `items` with `serializeItem` into a JSON-able array,
+// or return an error.
+func serializeArray[T any](
+	items []T,
+	serializeItem func(item T) (interface{}, error),
+) (result []interface{}, err error) {
+	result = make([]interface{}, len(items))
+	for i, item := range items {
+		result[i], err = serializeItem(item)
+		if err != nil {
+			mustSerializationError(err).prependIndex(i)
+			return
+		}
+	}
+	return
+}
+
+// Serialize `that` to a JSON-able value, or return an error.
+//
+// `ToJsonable` takes an `ourtypes.IClass`, but a list or a tuple item's own
+// (more specific) interface type, e.g., `ourtypes.ISomeItem`, can not be
+// unified with that when passing `ToJsonable` itself as a
+// `func(item T) (interface{}, error)` value -- Go function values are
+// invariant in their parameter type (no contravariance, unlike, say, a C#
+// delegate). Making this wrapper itself generic (instead of fixing its
+// parameter to `ourtypes.IClass`) lets the very same one be passed on bare,
+// uninstantiated, for every class-typed item regardless of its
+// concrete interface: Go infers both the item's type and this
+// wrapper's own type parameter together from the context of the
+// `serializeArray`/`serializeTupleN` call.
+func classAsJsonableInterface[T ourtypes.IClass](that T) (interface{}, error) {
+	return ToJsonable(that)
+}
+
+// Serialize [ourtypes.ISomeItem] as a JSON-able map.
+//
+// This function performs no dispatch! It is only used to serialize
+// the properties. If you want to serialize an instance of
+// [ourtypes.ISomeItem] with proper dispatch, call
+// [ToJsonable].
+func someItemToMap(
+	that ourtypes.ISomeItem,
+) (result map[string]interface{}, err error) {
+	result = make(map[string]interface{})
+
+	result["name"] = that.Name()
+
+	if that.Nickname() != nil {
+		result["nickname"] = *that.Nickname()
+	}
+
+	result["modelType"] = "SomeItem"
+
+	return
+}
+
+// Serialize [ourtypes.ISpecialItem] as a JSON-able map.
+//
+// This function performs no dispatch! It is only used to serialize
+// the properties. If you want to serialize an instance of
+// [ourtypes.ISpecialItem] with proper dispatch, call
+// [ToJsonable].
+func specialItemToMap(
+	that ourtypes.ISpecialItem,
+) (result map[string]interface{}, err error) {
+	result = make(map[string]interface{})
+
+	result["name"] = that.Name()
+
+	if that.Nickname() != nil {
+		result["nickname"] = *that.Nickname()
+	}
+
+	result["level"], err = int64ToJsonable(that.Level())
+	if err != nil {
+		mustSerializationError(err).prependName("Level()")
+		return
+	}
+
+	result["modelType"] = "SpecialItem"
+
+	return
+}
+
+// Serialize [ourtypes.IContainer] as a JSON-able map.
+//
+// This function performs no dispatch! It is only used to serialize
+// the properties. If you want to serialize an instance of
+// [ourtypes.IContainer] with proper dispatch, call
+// [ToJsonable].
+func containerToMap(
+	that ourtypes.IContainer,
+) (result map[string]interface{}, err error) {
+	result = make(map[string]interface{})
+
+	result["items"], err = serializeArray(
+		that.Items(), classAsJsonableInterface[ourtypes.IItem],
+	)
+	if err != nil {
+		mustSerializationError(err).prependName("Items()")
+		return
+	}
+
+	result["someItems"], err = serializeArray(
+		that.SomeItems(), classAsJsonableInterface[ourtypes.ISomeItem],
+	)
+	if err != nil {
+		mustSerializationError(err).prependName("SomeItems()")
+		return
+	}
+
+	if that.SpecialItems() != nil {
+		result["specialItems"], err = serializeArray(
+			that.SpecialItems(), classAsJsonableInterface[ourtypes.ISpecialItem],
+		)
+		if err != nil {
+			mustSerializationError(err).prependName("SpecialItems()")
+			return
+		}
+	}
+
+	return
+}
+
+// Serialize [ourtypes.IWrapper] as a JSON-able map.
+//
+// This function performs no dispatch! It is only used to serialize
+// the properties. If you want to serialize an instance of
+// [ourtypes.IWrapper] with proper dispatch, call
+// [ToJsonable].
+func wrapperToMap(
+	that ourtypes.IWrapper,
+) (result map[string]interface{}, err error) {
+	result = make(map[string]interface{})
+
+	result["container"], err = ToJsonable(that.Container())
+	if err != nil {
+		mustSerializationError(err).prependName("Container()")
+		return
+	}
+
+	return
+}
+
+// Serialize “that“ instance to a JSON-able representation.
+//
+// Return a structure which can be readily converted to JSON,
+// or an error if some value could not be converted.
+func ToJsonable(
+	that ourtypes.IClass,
+) (result map[string]interface{}, err error) {
+	switch that.ModelType() {
+	case ourtypes.ModelTypeSomeItem:
+		result, err = someItemToMap(
+			that.(ourtypes.ISomeItem),
+		)
+	case ourtypes.ModelTypeSpecialItem:
+		result, err = specialItemToMap(
+			that.(ourtypes.ISpecialItem),
+		)
+	case ourtypes.ModelTypeContainer:
+		result, err = containerToMap(
+			that.(ourtypes.IContainer),
+		)
+	case ourtypes.ModelTypeWrapper:
+		result, err = wrapperToMap(
+			that.(ourtypes.IWrapper),
+		)
+	default:
+		err = newSerializationError(
+			fmt.Sprintf(
+				"Unexpected model type literal: %v",
+				that.ModelType(),
+			),
+		)
+	}
+	return
+}
+
+// endregion
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/classes_with_descendants_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/classes_with_descendants_test.go
new file mode 100644
index 000000000..162a7b981
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/classes_with_descendants_test.go
@@ -0,0 +1,130 @@
+package jsonization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"testing"
+	ourjsonization "github.com/dummy-works/dummy/jsonization"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+)
+
+func TestItemRoundTripOKOverDescendant(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalSomeItem()
+
+	jsonable, err := ourjsonization.ToJsonable(instance)
+	if err != nil {
+		t.Fatalf(
+			"Failed to serialize the minimal SomeItem: %v",
+			err,
+		)
+		return
+	}
+
+	source := "<minimal SomeItem>"
+
+	deserialized, deseriaErr := ourjsonization.ItemFromJsonable(
+		jsonable,
+	)
+	ok := assertNoDeserializationError(t, deseriaErr, source)
+	if !ok {
+		return
+	}
+
+	anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+	ok = assertNoSerializationError(t, seriaErr, source)
+	if !ok {
+		return
+	}
+
+	ok = assertSerializationEqualsDeserialization(
+		t,
+		jsonable,
+		anotherJsonable,
+		source,
+	)
+	if !ok {
+		return
+	}
+}
+
+func TestItemDeserializationFail(t *testing.T) {
+	jsonable := any("this is not an object")
+
+	_, err := ourjsonization.ItemFromJsonable(
+		jsonable,
+	)
+
+	if err == nil {
+		t.Fatal("Expected an error, but got none.")
+		return
+	}
+
+	deseriaErr, ok := err.(*ourjsonization.DeserializationError)
+	if !ok {
+		t.Fatalf("Expected a de-serialization error, but got: %v", err)
+		return
+	}
+
+	pathString := deseriaErr.PathString()
+	if len(pathString) != 0 {
+		t.Fatalf(
+			"Expected an empty path in error, but got: %s",
+			pathString,
+		)
+		return
+	}
+
+	expectedMessage :=
+		"Expected a JSON object, but got string"
+
+	if deseriaErr.Message != expectedMessage {
+		t.Fatalf(
+			"Expected the deserialization error:\n%s\n, but got:\n%s",
+			expectedMessage, deseriaErr.Message,
+		)
+		return
+	}
+}
+
+func TestSomeItemRoundTripOKOverDescendant(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalSpecialItem()
+
+	jsonable, err := ourjsonization.ToJsonable(instance)
+	if err != nil {
+		t.Fatalf(
+			"Failed to serialize the minimal SpecialItem: %v",
+			err,
+		)
+		return
+	}
+
+	source := "<minimal SpecialItem>"
+
+	deserialized, deseriaErr := ourjsonization.SomeItemFromJsonable(
+		jsonable,
+	)
+	ok := assertNoDeserializationError(t, deseriaErr, source)
+	if !ok {
+		return
+	}
+
+	anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+	ok = assertNoSerializationError(t, seriaErr, source)
+	if !ok {
+		return
+	}
+
+	ok = assertSerializationEqualsDeserialization(
+		t,
+		jsonable,
+		anotherJsonable,
+		source,
+	)
+	if !ok {
+		return
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/common_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/common_test.go
new file mode 100644
index 000000000..98f55b485
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/common_test.go
@@ -0,0 +1,189 @@
+package jsonization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	ourjsonization "github.com/dummy-works/dummy/jsonization"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+)
+
+// Assert that there is no de-serialization error when de-serializing
+// from `source`.
+func assertNoDeserializationError(
+	t *testing.T,
+	err error,
+	source string,
+) (ok bool) {
+	ok = true
+	if err != nil {
+		ok = false
+		t.Fatalf(
+			"Expected no de-serialization error from %s, "+
+				"but got: %v",
+			source, err,
+		)
+		return
+	}
+	return
+}
+
+// Assert that there is no serialization error when serializing the instance
+// originally coming from `source`.
+func assertNoSerializationError(
+	t *testing.T,
+	err error,
+	source string,
+) (ok bool) {
+	ok = true
+	if err != nil {
+		ok = false
+		t.Fatalf(
+			"Expected no serialization error when serializing "+
+				"the instance obtained from %s, "+
+				"but got: %v",
+			source, err,
+		)
+		return
+	}
+	return
+}
+
+// Assert that the serialization `other`, as JSON-able, equals the original
+// JSON-able `that` read from `source`.
+func assertSerializationEqualsDeserialization(
+	t *testing.T,
+	that interface{},
+	other interface{},
+	source string,
+) (ok bool) {
+	ok = true
+
+	thatBytes, err := json.Marshal(that)
+	if err != nil {
+		panic(fmt.Sprintf("Failed to marshal that jsonable %v: %s", that, err.Error()))
+	}
+	thatText := string(thatBytes)
+
+	otherBytes, err := json.Marshal(other)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to marshal other jsonable %v: %s", other, err.Error(),
+			),
+		)
+	}
+	otherText := string(otherBytes)
+
+	if thatText != otherText {
+		ok = false
+		t.Fatalf(
+			"The serialization of the de-serialized instance from %s does not equal "+
+				"the original JSON-able:\nOriginal:\n%s\nSerialized:\n%s",
+			source, thatText, otherText,
+		)
+		return
+	}
+
+	return
+}
+
+// Assert that there is a de-serialization error.
+//
+// If [ourtesting.RecordMode] is set, the de-serialization error is re-recorded
+// to `expectedPth`. Otherwise, the error is compared against the golden file
+// `expectedPth`.
+func assertDeserializationErrorEqualsExpectedOrRecord(
+	t *testing.T,
+	err error,
+	source string,
+	expectedPth string,
+) (ok bool) {
+	ok = true
+
+	if err == nil {
+		ok = false
+		t.Fatalf("De-serialization error expected from %s, but got none", source)
+		return
+	}
+
+	var deseriaErr *ourjsonization.DeserializationError
+	deseriaErr, ok = err.(*ourjsonization.DeserializationError)
+	if !ok {
+		t.Fatalf("Expected a de-serialization error, but got: %v from %s", err, source)
+		return
+	}
+
+	// Add a new line for POSIX systems.
+	got := deseriaErr.Error() + "\n"
+
+	if ourtesting.RecordMode {
+		parent := filepath.Dir(expectedPth)
+		err := os.MkdirAll(parent, os.ModePerm)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to create the directory %s: %s", parent, err.Error(),
+				),
+			)
+		}
+
+		err = os.WriteFile(expectedPth, []byte(got), 0644)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to write to the file %s: %s", expectedPth, err.Error(),
+				),
+			)
+		}
+	} else {
+		_, err := os.Stat(expectedPth)
+		if err != nil {
+			ok = false
+			t.Fatalf(
+				"Failed to stat the file %s: %s; if the file does not exist, "+
+					"you probably want to record the test data by "+
+					"setting the environment variable %s",
+				expectedPth, err.Error(), ourtesting.RecordModeEnvironmentVariableName,
+			)
+			return
+		}
+
+		bb, err := os.ReadFile(expectedPth)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to read from file %s: %s", expectedPth, err.Error(),
+				),
+			)
+		}
+
+		expected := string(bb)
+
+		// NOTE (mristin):
+		// Git automatically strips and adds `\r`, so we have to remove it here
+		// to obtain a canonical text.
+		expected = strings.Replace(expected, "\r", "", -1)
+
+		if expected != got {
+			ok = false
+			t.Fatalf(
+				"What we got differs from the expected in %s. "+
+					"We got:\n%s\nWe expected:\n%s",
+				expectedPth, got, expected,
+			)
+			return
+		}
+	}
+
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/concrete_classes_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/concrete_classes_test.go
new file mode 100644
index 000000000..e1f2ee7ea
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/concrete_classes_test.go
@@ -0,0 +1,521 @@
+package jsonization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"path/filepath"
+	"sort"
+	"testing"
+	ourjsonization "github.com/dummy-works/dummy/jsonization"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Determine the path to the first recorded example of `modelType`.
+func mustFirstExpectedPath(t *testing.T, modelType string) string {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			modelType,
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	if len(pths) == 0 {
+		t.Fatalf(
+			"Expected at least one recorded example of %s, but got none",
+			modelType,
+		)
+	}
+
+	return pths[0]
+}
+
+// Assert that `that` can not be serialized to JSON, and that the failure
+// is reported at `expectedPath`.
+func assertSerializationFailsAt(
+	t *testing.T,
+	that ourtypes.IClass,
+	expectedPath string,
+) {
+	_, err := ourjsonization.ToJsonable(that)
+
+	if err == nil {
+		t.Fatalf(
+			"Expected the serialization to fail at %s, but it succeeded",
+			expectedPath,
+		)
+		return
+	}
+
+	seriaErr, ok := err.(*ourjsonization.SerializationError)
+	if !ok {
+		t.Fatalf(
+			"Expected a *SerializationError, but got %T: %v",
+			err, err,
+		)
+		return
+	}
+
+	if seriaErr.PathString() != expectedPath {
+		t.Fatalf(
+			"Expected the serialization to fail at %s, "+
+				"but it failed at %s: %s",
+			expectedPath, seriaErr.PathString(), seriaErr.Message,
+		)
+	}
+}
+
+func TestSomeItemRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"SomeItem",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.SomeItemFromJsonable(
+			jsonable,
+		)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			jsonable,
+			anotherJsonable,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSomeItemDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"SomeItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			_, deseriaErr := ourjsonization.SomeItemFromJsonable(
+				jsonable,
+			)
+			ok := assertDeserializationErrorEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestSpecialItemRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"SpecialItem",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.SpecialItemFromJsonable(
+			jsonable,
+		)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			jsonable,
+			anotherJsonable,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSpecialItemDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"SpecialItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			_, deseriaErr := ourjsonization.SpecialItemFromJsonable(
+				jsonable,
+			)
+			ok := assertDeserializationErrorEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestContainerRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"Container",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.ContainerFromJsonable(
+			jsonable,
+		)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			jsonable,
+			anotherJsonable,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestContainerDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"Container",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			_, deseriaErr := ourjsonization.ContainerFromJsonable(
+				jsonable,
+			)
+			ok := assertDeserializationErrorEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestWrapperRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"Wrapper",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.WrapperFromJsonable(
+			jsonable,
+		)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		anotherJsonable, seriaErr := ourjsonization.ToJsonable(deserialized)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			jsonable,
+			anotherJsonable,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestWrapperDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"Wrapper",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			_, deseriaErr := ourjsonization.WrapperFromJsonable(
+				jsonable,
+			)
+			ok := assertDeserializationErrorEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestSpecialItemSerializationFailOnOutOfRangeLevel(t *testing.T) {
+	pth := mustFirstExpectedPath(t, "SpecialItem")
+
+	for _, value := range []int64{
+		9007199254740992,
+		-9007199254740992,
+	} {
+		jsonable := ourtesting.MustReadJsonable(pth)
+
+		instance, deseriaErr := ourjsonization.SpecialItemFromJsonable(
+			jsonable,
+		)
+		if !assertNoDeserializationError(t, deseriaErr, pth) {
+			return
+		}
+
+		instance.SetLevel(value)
+
+		assertSerializationFailsAt(
+			t,
+			instance,
+			"Level()",
+		)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/enums_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/enums_test.go
new file mode 100644
index 000000000..1fd5a3ce4
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/jsonization/test/enums_test.go
@@ -0,0 +1,11 @@
+package jsonization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+
+)
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/common_jsonization.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/common_jsonization.go
new file mode 100644
index 000000000..ee8cf4a15
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/common_jsonization.go
@@ -0,0 +1,350 @@
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"path"
+	ourjsonization "github.com/dummy-works/dummy/jsonization"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Load a maximal example of [ourtypes.ISomeItem] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMaximalSomeItem(
+) (result ourtypes.ISomeItem) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"SomeItem",
+		"maximal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.SomeItemFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of ISomeItem " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.ISomeItem)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of ISomeItem at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a minimal example of [ourtypes.ISomeItem] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMinimalSomeItem(
+) (result ourtypes.ISomeItem) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"SomeItem",
+		"minimal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.SomeItemFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of ISomeItem " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.ISomeItem)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of ISomeItem at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a maximal example of [ourtypes.ISpecialItem] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMaximalSpecialItem(
+) (result ourtypes.ISpecialItem) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"SpecialItem",
+		"maximal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.SpecialItemFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of ISpecialItem " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.ISpecialItem)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of ISpecialItem at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a minimal example of [ourtypes.ISpecialItem] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMinimalSpecialItem(
+) (result ourtypes.ISpecialItem) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"SpecialItem",
+		"minimal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.SpecialItemFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of ISpecialItem " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.ISpecialItem)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of ISpecialItem at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a maximal example of [ourtypes.IContainer] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMaximalContainer(
+) (result ourtypes.IContainer) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"Container",
+		"maximal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.ContainerFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of IContainer " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.IContainer)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of IContainer at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a minimal example of [ourtypes.IContainer] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMinimalContainer(
+) (result ourtypes.IContainer) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"Container",
+		"minimal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.ContainerFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of IContainer " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.IContainer)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of IContainer at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a maximal example of [ourtypes.IWrapper] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMaximalWrapper(
+) (result ourtypes.IWrapper) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"Wrapper",
+		"maximal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.WrapperFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of IWrapper " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.IWrapper)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of IWrapper at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// Load a minimal example of [ourtypes.IWrapper] from
+// the test data directory.
+//
+// If there is any error, panic.
+func MustLoadMinimalWrapper(
+) (result ourtypes.IWrapper) {
+	pth := path.Join(
+		TestDataDir,
+		"Json",
+		"Expected",
+		"Wrapper",
+		"minimal.json",
+	)
+
+	jsonable := MustReadJsonable(pth)
+
+	instance, err := ourjsonization.WrapperFromJsonable(
+		jsonable,
+	)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to de-serialize an instance of IWrapper " +
+				"from %s: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	var ok bool
+	result, ok = instance.(ourtypes.IWrapper)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected to find an instance of IWrapper at %s, " +
+				"but got an instance of %T: %v",
+				pth, instance, instance,
+			),
+		)
+	}
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/constants.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/constants.go
new file mode 100644
index 000000000..38df0b3df
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/constants.go
@@ -0,0 +1,43 @@
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+const RecordModeEnvironmentVariableName string = (
+	"GITHUB_COM_DUMMY_WORKS_DUMMY_TEST_RECORD_MODE")
+
+// NOTE (mristin):
+// It is tedious to record manually all the expected error messages. Therefore we
+// include this variable to steer the automatic recording. We intentionally
+// intertwine the recording code with the test code to keep them close to each other
+// so that they are easier to maintain.
+var rM = os.Getenv(RecordModeEnvironmentVariableName)
+var RecordMode = rM == "1" || strings.ToLower(rM) == "true" || strings.ToLower(rM) == "on"
+
+const TestDataDirEnvironmentVariableName string = (
+	"GITHUB_COM_DUMMY_WORKS_DUMMY_TEST_DATA_DIR")
+
+func getTestDataDir() string {
+	variable := TestDataDirEnvironmentVariableName
+	val, ok := os.LookupEnv(variable)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Expected the environment variable to be set, but it was not: %s",
+				variable,
+			),
+		)
+	}
+	return val
+}
+
+var TestDataDir = getTestDataDir()
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/deep_equal.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/deep_equal.go
new file mode 100644
index 000000000..c75374b9c
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/deep_equal.go
@@ -0,0 +1,239 @@
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Perform a comparison for deep equality between `that` and `other` instance.
+//
+// The deep equality means that all the properties are checked for equality recursively.
+func deepEqualSomeItem(
+	that ourtypes.ISomeItem,
+	other ourtypes.ISomeItem,
+) bool {
+	thatName := that.Name()
+	otherName := other.Name()
+	if thatName != otherName {
+		return false
+	}
+
+	thatNickname := that.Nickname()
+	otherNickname := other.Nickname()
+	if
+		(thatNickname == nil && otherNickname != nil) ||
+		(thatNickname != nil && otherNickname == nil) {
+		return false
+	}
+	if thatNickname != nil {
+		if *thatNickname != *otherNickname {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` instance.
+//
+// The deep equality means that all the properties are checked for equality recursively.
+func deepEqualSpecialItem(
+	that ourtypes.ISpecialItem,
+	other ourtypes.ISpecialItem,
+) bool {
+	thatName := that.Name()
+	otherName := other.Name()
+	if thatName != otherName {
+		return false
+	}
+
+	thatNickname := that.Nickname()
+	otherNickname := other.Nickname()
+	if
+		(thatNickname == nil && otherNickname != nil) ||
+		(thatNickname != nil && otherNickname == nil) {
+		return false
+	}
+	if thatNickname != nil {
+		if *thatNickname != *otherNickname {
+			return false
+		}
+	}
+
+	thatLevel := that.Level()
+	otherLevel := other.Level()
+	if thatLevel != otherLevel {
+		return false
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` instance.
+//
+// The deep equality means that all the properties are checked for equality recursively.
+func deepEqualContainer(
+	that ourtypes.IContainer,
+	other ourtypes.IContainer,
+) bool {
+	thatItems := that.Items()
+	otherItems := other.Items()
+	if !deepEqualListOf_IItem(
+		thatItems,
+		otherItems,
+	) {
+		return false
+	}
+
+	thatSomeItems := that.SomeItems()
+	otherSomeItems := other.SomeItems()
+	if !deepEqualListOf_ISomeItem(
+		thatSomeItems,
+		otherSomeItems,
+	) {
+		return false
+	}
+
+	thatSpecialItems := that.SpecialItems()
+	otherSpecialItems := other.SpecialItems()
+	if
+		(thatSpecialItems == nil && otherSpecialItems != nil) ||
+		(thatSpecialItems != nil && otherSpecialItems == nil) {
+		return false
+	}
+	if thatSpecialItems != nil {
+		if !deepEqualListOf_ISpecialItem(
+			thatSpecialItems,
+			otherSpecialItems,
+		) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` instance.
+//
+// The deep equality means that all the properties are checked for equality recursively.
+func deepEqualWrapper(
+	that ourtypes.IWrapper,
+	other ourtypes.IWrapper,
+) bool {
+	thatContainer := that.Container()
+	otherContainer := other.Container()
+	if !DeepEqual(
+		thatContainer,
+		otherContainer,
+	) {
+		return false
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` container,
+// recursing into its items.
+func deepEqualListOf_IItem(
+	that []ourtypes.IItem,
+	other []ourtypes.IItem,
+) bool {
+	if len(that) != len(other) {
+		return false
+	}
+
+	for i := range that {
+		if !DeepEqual(
+			that[i],
+			other[i],
+		) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` container,
+// recursing into its items.
+func deepEqualListOf_ISomeItem(
+	that []ourtypes.ISomeItem,
+	other []ourtypes.ISomeItem,
+) bool {
+	if len(that) != len(other) {
+		return false
+	}
+
+	for i := range that {
+		if !DeepEqual(
+			that[i],
+			other[i],
+		) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Perform a comparison for deep equality between `that` and `other` container,
+// recursing into its items.
+func deepEqualListOf_ISpecialItem(
+	that []ourtypes.ISpecialItem,
+	other []ourtypes.ISpecialItem,
+) bool {
+	if len(that) != len(other) {
+		return false
+	}
+
+	for i := range that {
+		if !DeepEqual(
+			that[i],
+			other[i],
+		) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func DeepEqual(
+	that ourtypes.IClass,
+	other ourtypes.IClass,
+) bool {
+	if that.ModelType() != other.ModelType() {
+		return false
+	}
+
+	switch that.ModelType() {
+	case ourtypes.ModelTypeSomeItem:
+		return deepEqualSomeItem(
+			that.(ourtypes.ISomeItem),
+			other.(ourtypes.ISomeItem),
+		)
+	case ourtypes.ModelTypeSpecialItem:
+		return deepEqualSpecialItem(
+			that.(ourtypes.ISpecialItem),
+			other.(ourtypes.ISpecialItem),
+		)
+	case ourtypes.ModelTypeContainer:
+		return deepEqualContainer(
+			that.(ourtypes.IContainer),
+			other.(ourtypes.IContainer),
+		)
+	case ourtypes.ModelTypeWrapper:
+		return deepEqualWrapper(
+			that.(ourtypes.IWrapper),
+			other.(ourtypes.IWrapper),
+		)
+	}
+
+	panic(fmt.Sprintf("Unexpected model type: %d", that.ModelType()))
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/doc.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/doc.go
new file mode 100644
index 000000000..0857fea4f
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/doc.go
@@ -0,0 +1,6 @@
+// Package ourtesting provides the functions and data structures shared across
+// different tests.
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/filesystem.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/filesystem.go
new file mode 100644
index 000000000..08ec1ec17
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/filesystem.go
@@ -0,0 +1,69 @@
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+// Read the content of `pth` and parse it as a JSON.
+//
+// If any errors, panic.
+func MustReadJsonable(pth string) (jsonable interface{}) {
+	bb, err := os.ReadFile(pth)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to read the content of: %s",
+				pth,
+			),
+		)
+	}
+
+	err = json.Unmarshal(bb, &jsonable)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to parse the content of %s as JSON: %s",
+				pth, err.Error(),
+			),
+		)
+	}
+	return
+}
+
+func FindFilesBySuffixRecursively(root, suffix string) []string {
+	var a []string
+
+	_, statErr := os.Stat(root)
+	if statErr != nil {
+		if os.IsNotExist(statErr) {
+			return a
+		}
+
+		panic(fmt.Sprintf("Failed to stat %s: %s", root, statErr.Error()))
+	}
+
+	err := filepath.WalkDir(root, func(s string, d fs.DirEntry, e error) error {
+		if e != nil {
+			return e
+		}
+		if filepath.Ext(d.Name()) == suffix {
+			a = append(a, s)
+		}
+		return nil
+	})
+
+	if err != nil {
+		panic(fmt.Sprintf("Failed to walk %s: %s", root, err.Error()))
+	}
+	return a
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/tracing.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/tracing.go
new file mode 100644
index 000000000..cec4a835d
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/ourtesting/tracing.go
@@ -0,0 +1,20 @@
+package ourtesting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	ourstringification "github.com/dummy-works/dummy/stringification"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Represent `that` instance as a human-readable line of an iteration trace.
+func TraceMark(that ourtypes.IClass) string {
+	modelTypeText := ourstringification.MustModelTypeToString(
+		that.ModelType(),
+	)
+	return modelTypeText
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/reporting/reporting.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/reporting/reporting.go
new file mode 100644
index 000000000..86698a098
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/reporting/reporting.go
@@ -0,0 +1,240 @@
+// Package reporting provides structures and functions for reporting of errors.
+package reporting
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"strconv"
+)
+
+type NameSegment struct{
+	Name string
+}
+
+type IndexSegment struct{
+	Index int
+}
+
+// Represent a member of an open JSON-able object on a path to
+// the erroneous value.
+//
+// Unlike a [NameSegment], which names a property of one of our classes, a key
+// is known only at run time, and can be any string at all.
+type KeySegment struct{
+	Key string
+}
+
+type Path struct{
+	// A segments is expected to be either a name segment or an index segment.
+	segments []interface{}
+	start int
+}
+
+// Prepend the segment to the path.
+//
+// Grow segments exponentially if there is no place.
+func (p *Path) prepend(segment interface{}) {
+	// See: https://en.wikipedia.org/wiki/Amortized_analysis#Dynamic_array
+	if len(p.segments) == 0 {
+		p.segments = make([]interface{}, 1)
+		p.segments[0] = segment
+		p.start = 0
+	} else if p.start > 0 {
+		p.start--
+		p.segments[p.start] = segment
+	} else {
+		s := make([]interface{}, len(p.segments) * 2)
+		copy(s[len(p.segments):], p.segments)
+		p.start = len(p.segments) - 1
+		p.segments = s
+		p.segments[p.start] = segment
+	}
+}
+
+// Prepend the name segment to the path.
+func (p *Path) PrependName(segment *NameSegment) {
+	p.prepend(segment)
+}
+
+// Prepend the index segment to the path.
+func (p *Path) PrependIndex(segment *IndexSegment) {
+	p.prepend(segment)
+}
+
+// Prepend the key segment to the path.
+func (p *Path) PrependKey(segment *KeySegment) {
+	p.prepend(segment)
+}
+
+// Apply the `callback` on each segment.
+//
+// The segment object is a [NameSegment], an [IndexSegment] or a [KeySegment].
+func (p *Path) OverSegments(callback func(interface{})) {
+	start := p.start
+	for i := start; i < len(p.segments); i++ {
+		callback(p.segments[i])
+	}
+}
+
+// Match the property names which a JSON path writes after a dot; the other
+// names are written in brackets as JSON strings, *e.g.*, `["$eq"]`.
+var variableNameRe = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z_0-9]*$`)
+
+// Render the path with dots and subscripts.
+//
+// If `bracketNonVariableNames` is set, the names which are no variable names
+// are written in brackets as JSON strings.
+func renderPath(p *Path, bracketNonVariableNames bool) string {
+	var b strings.Builder
+	i := 0
+	p.OverSegments(func(s interface{}) {
+		switch v := s.(type) {
+		case *NameSegment:
+			if !bracketNonVariableNames || variableNameRe.MatchString(v.Name) {
+				if i > 0 {
+					b.WriteString(".")
+				}
+				b.WriteString(v.Name)
+			} else {
+				b.WriteString(`["`)
+				b.WriteString(escapeForJSONString(v.Name))
+				b.WriteString(`"]`)
+			}
+		case *IndexSegment:
+			b.WriteString("[")
+			b.WriteString(strconv.Itoa(v.Index))
+			b.WriteString("]")
+		case *KeySegment:
+			b.WriteString(`["`)
+			b.WriteString(escapeForJSONString(v.Key))
+			b.WriteString(`"]`)
+		default:
+			panic(
+				fmt.Sprintf(
+					"Unexpected segment of type %T: %v",
+					s, s,
+				),
+			)
+		}
+
+		i++
+	})
+	return b.String()
+}
+
+// Translate the path to a JSON path.
+//
+// The name segments are expected to denote the names of the properties
+// in JSON property names, not Golang property names.
+func ToJSONPath(p *Path) string {
+	return renderPath(p, true)
+}
+
+// Translate the path to a Golang access path.
+//
+// The name segments are expected to denote the names of the properties
+// in Golang, not JSON property names.
+func ToGolangPath(p *Path) string {
+	// NOTE(mristin):
+	// The name segments of a Golang path are accessors such as `Value()`,
+	// which we always write after a dot.
+	return renderPath(p, false)
+}
+
+// Escape the characters which a JSON string may not hold as they are.
+//
+// The control characters without a short escape are written as Unicode
+// escapes, as JSON.stringify does.
+func escapeForJSONString(
+	text string,
+) string {
+	var b strings.Builder
+	b.Grow(len(text))
+	for _, r := range text {
+		switch r {
+		case '\\':
+			b.WriteString(`\\`)
+		case '"':
+			b.WriteString(`\"`)
+		case '\b':
+			b.WriteString(`\b`)
+		case '\f':
+			b.WriteString(`\f`)
+		case '\n':
+			b.WriteString(`\n`)
+		case '\r':
+			b.WriteString(`\r`)
+		case '\t':
+			b.WriteString(`\t`)
+		default:
+			if r < 0x20 {
+				fmt.Fprintf(&b, `\u%04x`, r)
+			} else {
+				b.WriteRune(r)
+			}
+		}
+	}
+	return b.String()
+}
+
+var replacerForXPath = strings.NewReplacer(
+	"/", "&#47;",
+	"<", "&lt;",
+	">", "&gt;",
+	"\"", "&quot;",
+	"'", "&apos;",
+)
+
+// Escape special characters for XPath.
+func escapeForXPath(
+	text string,
+) string {
+	return replacerForXPath.Replace(text)
+}
+
+// Generate a relative XPath based on the path segments.
+//
+// Leave out the leading slash (`/`). This is helpful if we
+// want to embed the error report in a larger document with a prefix
+// *etc.*
+//
+// The indices of the segments are 0-based, while the indices of XPath are
+// 1-based, so we render the index `i` as `*[i + 1]`.
+func ToRelativeXPath(
+	p *Path,
+) string {
+	i := 0
+	var b strings.Builder
+	p.OverSegments(func(s interface{}) {
+		if i > 0 {
+			b.WriteString("/")
+		}
+
+		switch v := s.(type) {
+			case *NameSegment:
+				b.WriteString(escapeForXPath(v.Name))
+			case *IndexSegment:
+				b.WriteString(fmt.Sprintf("*[%d]", v.Index+1))
+			case *KeySegment:
+				// NOTE (mristin):
+				// A JSON-able object is written as an XML-RPC `<struct>`, which holds
+				// the key of a member in a `<name>` child element, and not in
+				// an attribute, so the XPath has to match on that child element.
+				b.WriteString(
+					fmt.Sprintf(`member[name="%s"]`, escapeForXPath(v.Key)),
+				)
+			default:
+				panic(fmt.Sprintf("Unexpected segment of type %T: %v", s, s))
+		}
+		
+		i++
+	})
+	return b.String()
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stringification/stringification.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stringification/stringification.go
new file mode 100644
index 000000000..3dd35be05
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/stringification/stringification.go
@@ -0,0 +1,74 @@
+// Package stringification converts enumerations from and to string representations.
+package stringification
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+var modelTypeFromStringMap = map[string]ourtypes.ModelType {
+	"SomeItem": ourtypes.ModelTypeSomeItem,
+	"SpecialItem": ourtypes.ModelTypeSpecialItem,
+	"Container": ourtypes.ModelTypeContainer,
+	"Wrapper": ourtypes.ModelTypeWrapper,
+}
+
+// Parse `text` as a string representation of [ourtypes.ModelType].
+//
+// If not ok, the literal result is undefined.
+func ModelTypeFromString(
+	text string,
+) (literal ourtypes.ModelType, ok bool) {
+	literal, ok = modelTypeFromStringMap[text]
+	return
+}
+
+var modelTypeToStringArray = [...]string {
+	"SomeItem",
+	"SpecialItem",
+	"Container",
+	"Wrapper",
+}
+
+// Translate `value` from [ourtypes.ModelType] to a string.
+//
+// If the value is not valid, the OK is false and the string representation is
+// undefined.
+func ModelTypeToString(
+	value ourtypes.ModelType,
+) (result string, ok bool) {
+	i := int(value)
+	ok =
+		i >= 0 &&
+		i < len(modelTypeToStringArray)
+
+	if !ok {
+		return
+	}
+	result = modelTypeToStringArray[value]
+	return
+}
+
+// Translate the `value` from [ourtypes.ModelType] to a string.
+//
+// Panic if the given value is invalid.
+func MustModelTypeToString(
+	value ourtypes.ModelType,
+) string {
+	result, ok := ModelTypeToString(value)
+	if !ok {
+		panic(
+			fmt.Sprintf(
+				"Invalid value of ModelType: %v",
+				value,
+			),
+		)
+	}
+	return result
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/common.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/common.go
new file mode 100644
index 000000000..6fb2867ce
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/common.go
@@ -0,0 +1,96 @@
+package types_descend_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Trace the `instance` and compare the trace against the golden one from
+// the test data, or re-record the trace if [ourtesting.RecordMode] is set.
+//
+// If `onlyOnce`, trace the `instance` with [ourtypes.DescendOnce]. Otherwise,
+// trace with [ourtypes.Descend].
+//
+// If we are comparing, and not recording, return the error message if
+// the expected and the obtained trace differ.
+func compareOrRerecordTrace(
+	instance ourtypes.IClass,
+	expectedPath string,
+	onlyOnce bool,
+) (message *string) {
+	lines := []string{ourtesting.TraceMark(instance)}
+
+	if onlyOnce {
+		instance.DescendOnce(func(descendant ourtypes.IClass) (abort bool) {
+			lines = append(lines, ourtesting.TraceMark(descendant))
+			return
+		})
+	} else {
+		instance.Descend(func(descendant ourtypes.IClass) (abort bool) {
+			lines = append(lines, ourtesting.TraceMark(descendant))
+			return
+		})
+	}
+
+	got := strings.Join(lines, "\n")
+
+	// Add a new line for POSIX systems.
+	got += "\n"
+
+	if ourtesting.RecordMode {
+		parent := filepath.Dir(expectedPath)
+		err := os.MkdirAll(parent, os.ModePerm)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to create the directory %s: %s", parent, err.Error(),
+				),
+			)
+		}
+
+		err = os.WriteFile(expectedPath, []byte(got), 0644)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to write to the file %s: %s", expectedPath, err.Error(),
+				),
+			)
+		}
+	} else {
+		bb, err := os.ReadFile(expectedPath)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to read from file %s: %s", expectedPath, err.Error(),
+				),
+			)
+		}
+
+		expected := string(bb)
+
+		// NOTE (mristin):
+		// Git automatically strips and adds `\r`, so we have to remove it here
+		// to obtain a canonical text.
+		expected = strings.Replace(expected, "\r", "", -1)
+
+		if expected != got {
+			text := fmt.Sprintf(
+				"What we got differs from the expected in %s. "+
+					"We got:\n%s\nWe expected:\n%s",
+				expectedPath, got, expected,
+			)
+			message = &text
+		}
+	}
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_once_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_once_test.go
new file mode 100644
index 000000000..f97dd13ad
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_once_test.go
@@ -0,0 +1,109 @@
+package types_descend_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"path/filepath"
+	"testing"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+)
+
+func TestDescendOnceOnAnInstanceOfSomeItem(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalSomeItem()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"DescendOnce",
+		"SomeItem",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := true
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnceOnAnInstanceOfSpecialItem(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalSpecialItem()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"DescendOnce",
+		"SpecialItem",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := true
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnceOnAnInstanceOfContainer(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalContainer()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"DescendOnce",
+		"Container",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := true
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnceOnAnInstanceOfWrapper(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalWrapper()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"DescendOnce",
+		"Wrapper",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := true
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_test.go
new file mode 100644
index 000000000..c16a21652
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/descend_test/descend_test.go
@@ -0,0 +1,109 @@
+package types_descend_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"path/filepath"
+	"testing"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+)
+
+func TestDescendOnAnInstanceOfSomeItem(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalSomeItem()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"Descend",
+		"SomeItem",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := false
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnAnInstanceOfSpecialItem(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalSpecialItem()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"Descend",
+		"SpecialItem",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := false
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnAnInstanceOfContainer(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalContainer()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"Descend",
+		"Container",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := false
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+func TestDescendOnAnInstanceOfWrapper(
+	t *testing.T,
+) {
+	instance := ourtesting.MustLoadMaximalWrapper()
+
+	expectedPth := filepath.Join(
+		ourtesting.TestDataDir,
+		"Descend",
+		"Wrapper",
+		"maximal.json.trace",
+	)
+
+	onlyOnce := false
+
+	message := compareOrRerecordTrace(
+		instance,
+		expectedPth,
+		onlyOnce,
+	)
+	if message != nil {
+		t.Fatal(*message)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/is_xxx_test/is_xxx_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/is_xxx_test/is_xxx_test.go
new file mode 100644
index 000000000..666f38e59
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/is_xxx_test/is_xxx_test.go
@@ -0,0 +1,157 @@
+package types_is_xxx_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"testing"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+func TestIsXxxOnAnInstanceOfSomeItem(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalSomeItem()
+
+	if !ourtypes.IsSomeItem(instance) {
+		t.Errorf(
+			"Expected IsSomeItem to be true on an instance " +
+			"of ISomeItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsSpecialItem(instance) {
+		t.Errorf(
+			"Expected IsSpecialItem to be false on an instance " +
+			"of ISomeItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsContainer(instance) {
+		t.Errorf(
+			"Expected IsContainer to be false on an instance " +
+			"of ISomeItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsWrapper(instance) {
+		t.Errorf(
+			"Expected IsWrapper to be false on an instance " +
+			"of ISomeItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+}
+
+func TestIsXxxOnAnInstanceOfSpecialItem(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalSpecialItem()
+
+	if !ourtypes.IsSomeItem(instance) {
+		t.Errorf(
+			"Expected IsSomeItem to be true on an instance " +
+			"of ISpecialItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if !ourtypes.IsSpecialItem(instance) {
+		t.Errorf(
+			"Expected IsSpecialItem to be true on an instance " +
+			"of ISpecialItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsContainer(instance) {
+		t.Errorf(
+			"Expected IsContainer to be false on an instance " +
+			"of ISpecialItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsWrapper(instance) {
+		t.Errorf(
+			"Expected IsWrapper to be false on an instance " +
+			"of ISpecialItem with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+}
+
+func TestIsXxxOnAnInstanceOfContainer(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalContainer()
+
+	if ourtypes.IsSomeItem(instance) {
+		t.Errorf(
+			"Expected IsSomeItem to be false on an instance " +
+			"of IContainer with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsSpecialItem(instance) {
+		t.Errorf(
+			"Expected IsSpecialItem to be false on an instance " +
+			"of IContainer with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if !ourtypes.IsContainer(instance) {
+		t.Errorf(
+			"Expected IsContainer to be true on an instance " +
+			"of IContainer with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsWrapper(instance) {
+		t.Errorf(
+			"Expected IsWrapper to be false on an instance " +
+			"of IContainer with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+}
+
+func TestIsXxxOnAnInstanceOfWrapper(t *testing.T) {
+	instance := ourtesting.MustLoadMinimalWrapper()
+
+	if ourtypes.IsSomeItem(instance) {
+		t.Errorf(
+			"Expected IsSomeItem to be false on an instance " +
+			"of IWrapper with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsSpecialItem(instance) {
+		t.Errorf(
+			"Expected IsSpecialItem to be false on an instance " +
+			"of IWrapper with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if ourtypes.IsContainer(instance) {
+		t.Errorf(
+			"Expected IsContainer to be false on an instance " +
+			"of IWrapper with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+
+	if !ourtypes.IsWrapper(instance) {
+		t.Errorf(
+			"Expected IsWrapper to be true on an instance " +
+			"of IWrapper with runtime type %T and with model type %v",
+			instance, instance.ModelType(),
+		)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/types.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/types.go
new file mode 100644
index 000000000..12f3ded5f
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/types.go
@@ -0,0 +1,704 @@
+// Package types provides the data structures corresponding to the meta-model.
+//
+// Test the variance of the containers passed as arguments.
+//
+// A read-only `Sequence[...]` argument of a verification function is generic if its
+// items are instances of a class with descendants, so that the sequences of
+// the descendants can be passed to it without a copy. The arguments of the methods
+// and the mutable `List[...]` arguments remain invariant.
+package types
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+// Enumerate the model types for faster type switches.
+//
+// For example, you can use an array of function pointers to
+// implement such a switch.
+type ModelType int
+const (
+	ModelTypeSomeItem ModelType = iota
+	ModelTypeSpecialItem
+	ModelTypeContainer
+	ModelTypeWrapper
+)
+
+// Represent the most general interface of the meta-model.
+type IClass interface {
+	// Return the concrete model type at run-time.
+	//
+	// Use the model type if you want to switch on the concrete model type
+	// in efficient manner, as the compiler will most probably implement
+	// the switch in form of a jump table.
+	ModelType() ModelType
+
+	// Apply the action on the instances referenced from this instance.
+	//
+	// If any of the actions returns abort `true`, the descent is immediately
+	// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+	//
+	// We do not recurse into the referenced instances.
+	//
+	// The action is not applied on this instance.
+	DescendOnce(action func(IClass) bool) (abort bool)
+
+	// Apply the action recursively on the instances referenced from this instance.
+	//
+	// If any of the actions returns abort `true`, the descent is immediately
+	// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+	//
+	// The action is not applied on this instance.
+	Descend(action func(IClass) bool) (abort bool)
+}
+
+type IItem interface {
+	IClass
+
+	Name() string;
+
+	SetName(
+		value string,
+	);
+
+	Nickname() *string;
+
+	SetNickname(
+		value *string,
+	);
+}
+
+// Check whether the instance corresponds to [ourtypes.IItem]
+// based on its run-time model type.
+//
+// The implementation uses a switch statements which is
+// most probably compiled as an efficient jump table by the compiler.
+func IsItem(
+	that IClass,
+) (ok bool) {
+	switch that.ModelType() {
+	case ModelTypeSomeItem:
+		ok = true
+	case ModelTypeSpecialItem:
+		ok = true
+	}
+	return
+}
+
+type ISomeItem interface {
+	IItem
+}
+
+// Check whether the instance corresponds to [ourtypes.ISomeItem]
+// based on its run-time model type.
+//
+// The implementation uses a switch statements which is
+// most probably compiled as an efficient jump table by the compiler.
+func IsSomeItem(
+	that IClass,
+) (ok bool) {
+	switch that.ModelType() {
+	case ModelTypeSomeItem:
+		ok = true
+	case ModelTypeSpecialItem:
+		ok = true
+	}
+	return
+}
+
+// Implements ISomeItem.
+type SomeItem struct {
+	name string
+	nickname *string
+}
+
+func (si *SomeItem) Name(
+) string {
+	return si.name
+}
+
+func (si *SomeItem) SetName(
+	value string,
+) {
+	si.name = value
+}
+
+func (si *SomeItem) Nickname(
+) *string {
+	return si.nickname
+}
+
+func (si *SomeItem) SetNickname(
+	value *string,
+) {
+	si.nickname = value
+}
+
+func (si *SomeItem) ModelType(
+) ModelType {
+	return ModelTypeSomeItem
+}
+
+// Apply the action on the instances referenced from si.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// We do not recurse into the referenced instances.
+//
+// The action is not applied on si.
+func (si *SomeItem) DescendOnce(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_SomeItem(si, action, false)
+}
+
+// Apply the action recursively on the instances referenced from si.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on si.
+func (si *SomeItem) Descend(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_SomeItem(si, action, true)
+}
+
+// Apply the action on the instances referenced from that, and recursively
+// on their descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on that.
+func descend_SomeItem(
+	that *SomeItem,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	// No descendable properties
+
+	return
+}
+
+// Create a new instance of SomeItem with
+// the given properties.
+func NewSomeItem(
+	name string,
+) *SomeItem {
+	return &SomeItem{
+		name: name,
+		nickname: nil,
+	}
+}
+
+type ISpecialItem interface {
+	ISomeItem
+
+	Level() int64;
+
+	SetLevel(
+		value int64,
+	);
+}
+
+// Check whether the instance corresponds to [ourtypes.ISpecialItem]
+// based on its run-time model type.
+//
+// The implementation uses a switch statements which is
+// most probably compiled as an efficient jump table by the compiler.
+func IsSpecialItem(
+	that IClass,
+) (ok bool) {
+	ok = that.ModelType() == ModelTypeSpecialItem
+	return
+}
+
+// Implements ISpecialItem.
+type SpecialItem struct {
+	name string
+	nickname *string
+	level int64
+}
+
+func (si *SpecialItem) Name(
+) string {
+	return si.name
+}
+
+func (si *SpecialItem) SetName(
+	value string,
+) {
+	si.name = value
+}
+
+func (si *SpecialItem) Nickname(
+) *string {
+	return si.nickname
+}
+
+func (si *SpecialItem) SetNickname(
+	value *string,
+) {
+	si.nickname = value
+}
+
+func (si *SpecialItem) Level(
+) int64 {
+	return si.level
+}
+
+func (si *SpecialItem) SetLevel(
+	value int64,
+) {
+	si.level = value
+}
+
+func (si *SpecialItem) ModelType(
+) ModelType {
+	return ModelTypeSpecialItem
+}
+
+// Apply the action on the instances referenced from si.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// We do not recurse into the referenced instances.
+//
+// The action is not applied on si.
+func (si *SpecialItem) DescendOnce(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_SpecialItem(si, action, false)
+}
+
+// Apply the action recursively on the instances referenced from si.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on si.
+func (si *SpecialItem) Descend(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_SpecialItem(si, action, true)
+}
+
+// Apply the action on the instances referenced from that, and recursively
+// on their descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on that.
+func descend_SpecialItem(
+	that *SpecialItem,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	// No descendable properties
+
+	return
+}
+
+// Create a new instance of SpecialItem with
+// the given properties.
+func NewSpecialItem(
+	name string,
+	level int64,
+) *SpecialItem {
+	return &SpecialItem{
+		name: name,
+		level: level,
+		nickname: nil,
+	}
+}
+
+type IContainer interface {
+	IClass
+
+	Items() []IItem;
+
+	SetItems(
+		value []IItem,
+	);
+
+	SomeItems() []ISomeItem;
+
+	SetSomeItems(
+		value []ISomeItem,
+	);
+
+	SpecialItems() []ISpecialItem;
+
+	SetSpecialItems(
+		value []ISpecialItem,
+	);
+
+	// Count the items.
+	//
+	// The arguments of the methods are never generic, so only the sequences of
+	// [IItem] can be passed to it, but not the sequences of
+	// the descendants.
+	CountItems(
+		items []IItem,
+	) int64;
+}
+
+// Check whether the instance corresponds to [ourtypes.IContainer]
+// based on its run-time model type.
+//
+// The implementation uses a switch statements which is
+// most probably compiled as an efficient jump table by the compiler.
+func IsContainer(
+	that IClass,
+) (ok bool) {
+	ok = that.ModelType() == ModelTypeContainer
+	return
+}
+
+// Implements IContainer.
+type Container struct {
+	items []IItem
+	someItems []ISomeItem
+	specialItems []ISpecialItem
+}
+
+func (c *Container) Items(
+) []IItem {
+	return c.items
+}
+
+func (c *Container) SetItems(
+	value []IItem,
+) {
+	c.items = value
+}
+
+func (c *Container) SomeItems(
+) []ISomeItem {
+	return c.someItems
+}
+
+func (c *Container) SetSomeItems(
+	value []ISomeItem,
+) {
+	c.someItems = value
+}
+
+func (c *Container) SpecialItems(
+) []ISpecialItem {
+	return c.specialItems
+}
+
+func (c *Container) SetSpecialItems(
+	value []ISpecialItem,
+) {
+	c.specialItems = value
+}
+
+func (c *Container) ModelType(
+) ModelType {
+	return ModelTypeContainer
+}
+
+// Count the items.
+//
+// The arguments of the methods are never generic, so only the sequences of
+// [IItem] can be passed to it, but not the sequences of
+// the descendants.
+func (c *Container) CountItems(
+	items []IItem,
+) int64 {
+	return int64(len(items))
+}
+
+// Apply the action on the instances referenced from c.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// We do not recurse into the referenced instances.
+//
+// The action is not applied on c.
+func (c *Container) DescendOnce(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_Container(c, action, false)
+}
+
+// Apply the action recursively on the instances referenced from c.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on c.
+func (c *Container) Descend(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_Container(c, action, true)
+}
+
+// Apply the action on the instances referenced from that, and recursively
+// on their descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on that.
+func descend_Container(
+	that *Container,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	abort = descend_ListOf_IItem(
+		that.items,
+		action,
+		recurse,
+	)
+	if abort {
+		return
+	}
+
+	abort = descend_ListOf_ISomeItem(
+		that.someItems,
+		action,
+		recurse,
+	)
+	if abort {
+		return
+	}
+
+	if that.specialItems != nil {
+		abort = descend_ListOf_ISpecialItem(
+			that.specialItems,
+			action,
+			recurse,
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Create a new instance of Container with
+// the given properties.
+func NewContainer(
+	items []IItem,
+	someItems []ISomeItem,
+) *Container {
+	return &Container{
+		items: items,
+		someItems: someItems,
+		specialItems: nil,
+	}
+}
+
+type IWrapper interface {
+	IClass
+
+	Container() IContainer;
+
+	SetContainer(
+		value IContainer,
+	);
+}
+
+// Check whether the instance corresponds to [ourtypes.IWrapper]
+// based on its run-time model type.
+//
+// The implementation uses a switch statements which is
+// most probably compiled as an efficient jump table by the compiler.
+func IsWrapper(
+	that IClass,
+) (ok bool) {
+	ok = that.ModelType() == ModelTypeWrapper
+	return
+}
+
+// Implements IWrapper.
+type Wrapper struct {
+	container IContainer
+}
+
+func (w *Wrapper) Container(
+) IContainer {
+	return w.container
+}
+
+func (w *Wrapper) SetContainer(
+	value IContainer,
+) {
+	w.container = value
+}
+
+func (w *Wrapper) ModelType(
+) ModelType {
+	return ModelTypeWrapper
+}
+
+// Apply the action on the instances referenced from w.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// We do not recurse into the referenced instances.
+//
+// The action is not applied on w.
+func (w *Wrapper) DescendOnce(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_Wrapper(w, action, false)
+}
+
+// Apply the action recursively on the instances referenced from w.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on w.
+func (w *Wrapper) Descend(
+	action func(IClass) bool,
+) (abort bool) {
+	return descend_Wrapper(w, action, true)
+}
+
+// Apply the action on the instances referenced from that, and recursively
+// on their descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+//
+// The action is not applied on that.
+func descend_Wrapper(
+	that *Wrapper,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	abort = action(
+		that.container,
+	)
+	if abort {
+		return
+	}
+
+	if recurse {
+		abort = that.container.Descend(
+			action,
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Create a new instance of Wrapper with
+// the given properties.
+func NewWrapper(
+	container IContainer,
+) *Wrapper {
+	return &Wrapper{
+		container: container,
+	}
+}
+
+// Apply the action on the instances held by that, and recursively on their
+// descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+func descend_ListOf_IItem(
+	that []IItem,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	for _, item := range that {
+		abort = action(
+			item,
+		)
+		if abort {
+			return
+		}
+
+		if recurse {
+			abort = item.Descend(
+				action,
+			)
+			if abort {
+				return
+			}
+		}
+	}
+
+	return
+}
+
+// Apply the action on the instances held by that, and recursively on their
+// descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+func descend_ListOf_ISomeItem(
+	that []ISomeItem,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	for _, item := range that {
+		abort = action(
+			item,
+		)
+		if abort {
+			return
+		}
+
+		if recurse {
+			abort = item.Descend(
+				action,
+			)
+			if abort {
+				return
+			}
+		}
+	}
+
+	return
+}
+
+// Apply the action on the instances held by that, and recursively on their
+// descendants if recurse is set.
+//
+// If any of the actions returns abort `true`, the descent is immediately
+// stopped, and abort `true` is also returned. Otherwise, return abort `false`.
+func descend_ListOf_ISpecialItem(
+	that []ISpecialItem,
+	action func(IClass) bool,
+	recurse bool,
+) (abort bool) {
+	for _, item := range that {
+		abort = action(
+			item,
+		)
+		if abort {
+			return
+		}
+
+		if recurse {
+			abort = item.Descend(
+				action,
+			)
+			if abort {
+				return
+			}
+		}
+	}
+
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/xxx_or_default_test/xxx_or_default_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/xxx_or_default_test/xxx_or_default_test.go
new file mode 100644
index 000000000..47baecccc
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/types/xxx_or_default_test/xxx_or_default_test.go
@@ -0,0 +1,153 @@
+package types_xxx_or_default_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"path/filepath"
+	"fmt"
+	"encoding/json"
+	"os"
+	"reflect"
+	"strings"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Represent explicitly a literal of an enumeration.
+type enumerationLiteral struct {
+	enumerationName string
+	literalName string
+}
+
+func (el *enumerationLiteral) String() string {
+	return fmt.Sprintf("%s.%s", el.enumerationName, el.literalName)
+}
+
+// Marshal the value as JSON, or panic otherwise.
+func mustJSONMarshal(value interface{}) string {
+	bb, err := json.Marshal(value)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to marshal the value %v to JSON: %s",
+				value, err.Error(),
+			),
+		)
+	}
+
+	return string(bb)
+}
+
+func stringify(value interface{}) (got string) {
+	if value == nil {
+		got = mustJSONMarshal(value)
+	} else {
+		// See: https://stackoverflow.com/questions/38748098/golang-type-switch-how-to-match-a-generic-slice-array-map-chan
+		reflected := reflect.ValueOf(value)
+
+		if reflected.Kind() == reflect.Slice {
+			parts := make([]string, reflected.Len())
+
+			for i := 0; i < reflected.Len(); i++ {
+				item := reflected.Index(i)
+				parts[i] = stringify(item)
+			}
+
+			got = fmt.Sprintf("[%s]", strings.Join(parts, ", "))
+		} else {
+			switch casted := value.(type) {
+			case bool:
+				got = mustJSONMarshal(casted)
+			case int:
+				got = mustJSONMarshal(casted)
+			case string:
+				got = mustJSONMarshal(casted)
+			case []byte:
+				got = fmt.Sprintf("%d byte(s)", len(casted))
+			case *enumerationLiteral:
+				got = casted.String()
+			case ourtypes.IClass:
+				got = ourtesting.TraceMark(casted)
+			default:
+				panic(
+					fmt.Sprintf(
+						"We do not know hot to represent the value of type %T: %v",
+						value, value,
+					),
+				)
+			}
+		}
+	}
+
+	return
+}
+
+// Represent `value` such that we can immediately check whether it is the default value
+// or the set one.
+//
+// We compare it against the recorded golden file, if not [ourtesting.RecordMode].
+// If there are differences, a `message` is set.
+//
+// Otherwise, when [ourtesting.RecordMode] is set, we re-record the golden file.
+func compareOrRerecordValue(
+	value interface{},
+	expectedPath string,
+) (message *string) {
+	got := stringify(value)
+
+	// NOTE (mristin):
+	// Add a new line for POSIX systems.
+	got += "\n"
+
+	if ourtesting.RecordMode {
+		parent := filepath.Dir(expectedPath)
+		err := os.MkdirAll(parent, os.ModePerm)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to create the directory %s: %s", parent, err.Error(),
+				),
+			)
+		}
+
+		err = os.WriteFile(expectedPath, []byte(got), 0644)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to write to the file %s: %s", expectedPath, err.Error(),
+				),
+			)
+		}
+	} else {
+		bb, err := os.ReadFile(expectedPath)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to read from file %s: %s", expectedPath, err.Error(),
+				),
+			)
+		}
+
+		expected := string(bb)
+
+		// NOTE (mristin):
+		// Git automatically strips and adds `\r`, so we have to remove it here
+		// to obtain a canonical text.
+		expected = strings.Replace(expected, "\r", "", -1)
+
+		if expected != got {
+			text := fmt.Sprintf(
+				"What we got differs from the expected in %s. " +
+				"We got:\n%s\nWe expected:\n%s",
+				expectedPath, got, expected,
+			)
+			message = &text
+		}
+	}
+
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/test/verification_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/test/verification_test.go
new file mode 100644
index 000000000..4a2aef010
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/test/verification_test.go
@@ -0,0 +1,692 @@
+package verification_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"testing"
+	ourjsonization "github.com/dummy-works/dummy/jsonization"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+	ourverification "github.com/dummy-works/dummy/verification"
+)
+
+// Assert that there are no verification errors in the `instance` de-serialized
+// from `source`.
+func assertNoVerificationErrors(
+	t *testing.T,
+	instance ourtypes.IClass,
+	source string,
+) (ok bool) {
+	errors := make([]*ourverification.VerificationError, 0)
+	ourverification.Verify(
+		instance,
+		func(err *ourverification.VerificationError) (abort bool) {
+			errors = append(errors, err)
+			return
+		},
+	)
+
+	ok = true
+	if len(errors) > 0 {
+		ok = false
+
+		var sb strings.Builder
+
+		sb.WriteString(
+			fmt.Sprintf(
+				"Expected no errors when verifying the instance de-serialized from "+
+					"%s, but got %d error(s)\n",
+				source, len(errors),
+			),
+		)
+
+		for i, err := range errors {
+			sb.WriteString(
+				fmt.Sprintf(
+					"Error %d:\n%s: %s\n",
+					i+1,
+					err.PathString(),
+					err.Message,
+				),
+			)
+		}
+
+		jsonable, seriaErr := ourjsonization.ToJsonable(instance)
+		if seriaErr != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to serialize instance to JSON obtained from %s: %s",
+					source, seriaErr.Error(),
+				),
+			)
+		}
+		jsonableBytes, err := json.Marshal(jsonable)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to marshal to JSON an instance serialized from %s: %s",
+					source, err.Error(),
+				),
+			)
+		}
+
+		sb.WriteString("Instance:\n")
+		sb.WriteString(string(jsonableBytes))
+
+		t.Fatal(sb.String())
+	}
+	return
+}
+
+// Assert that either the verification errors match the recorded ones at `pth`, if
+// [ourtesting.RecordMode] is set, or re-record the verification errors at `pth`.
+func assertEqualsExpectedOrRerecordVerificationErrors(
+	t *testing.T,
+	errors []*ourverification.VerificationError,
+	source string,
+	expectedPth string,
+) (ok bool) {
+	ok = true
+	if len(errors) == 0 {
+		ok = false
+		t.Fatalf(
+			"Expected at least one verification error, "+
+				"but got none when verifying the model loaded from: %s",
+			source,
+		)
+	}
+
+	parts := make([]string, len(errors))
+	for i, verErr := range errors {
+		parts[i] = fmt.Sprintf(
+			"%s: %s",
+			verErr.PathString(),
+			verErr.Message,
+		)
+	}
+
+	// Add a newline for POSIX systems
+	got := strings.Replace(strings.Join(parts, ";\n"), "\r\n", "\n", -1) + "\n"
+
+	if ourtesting.RecordMode {
+		parent := filepath.Dir(expectedPth)
+		err := os.MkdirAll(parent, os.ModePerm)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to create the directory %s: %s", parent, err.Error(),
+				),
+			)
+		}
+
+		err = os.WriteFile(expectedPth, []byte(got), 0644)
+		if err != nil {
+			ok = false
+			t.Fatalf("Failed to write to %s: %s", expectedPth, err.Error())
+			return
+		}
+	} else {
+		_, err := os.Stat(expectedPth)
+		if err != nil {
+			ok = false
+			t.Fatalf(
+				"Failed to stat the file %s: %s; if the file does not exist, "+
+					"you probably want to record the test data by "+
+					"setting the environment variable %s",
+				expectedPth, err.Error(), ourtesting.RecordModeEnvironmentVariableName,
+			)
+			return
+		}
+
+		var bb []byte
+		bb, err = os.ReadFile(expectedPth)
+		if err != nil {
+			ok = false
+			t.Fatalf("Failed to read from %s: %s", expectedPth, err.Error())
+			return
+		}
+		expected := strings.ReplaceAll(string(bb), "\r\n", "\n")
+
+		if expected != got {
+			ok = false
+			t.Fatalf(
+				"The expected verification errors (read from %s) in the model "+
+					"de-serialized from %s do not match the obtained ones. "+
+					"Expected:\n%s\nGot:\n%s",
+				expectedPth, source, expected, got,
+			)
+			return
+		}
+	}
+	return
+}
+
+func TestSomeItemOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"SomeItem",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.SomeItemFromJsonable(
+			jsonable,
+		)
+		if deseriaErr != nil {
+			t.Fatalf(
+				"Unexpected deserialization error from %s: %s",
+				pth, deseriaErr.Error(),
+			)
+			return
+		}
+
+		var errors []*ourverification.VerificationError
+		ourverification.Verify(
+			deserialized,
+			func(veriErr *ourverification.VerificationError) (abort bool) {
+				errors = append(errors, veriErr)
+				return
+			},
+		)
+
+		ok := assertNoVerificationErrors(
+			t,
+			deserialized,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSomeItemFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Invalid",
+		"*",  // This asterisk represents the cause.
+		"SomeItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"VerificationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".errors",
+			)
+
+			deserialized, deseriaErr := ourjsonization.SomeItemFromJsonable(
+				jsonable,
+			)
+			if deseriaErr != nil {
+				t.Fatalf(
+					"Unexpected deserialization error from %s: %s",
+					pth, deseriaErr.Error(),
+				)
+				return
+			}
+
+			var errors []*ourverification.VerificationError
+			ourverification.Verify(
+				deserialized,
+				func(err *ourverification.VerificationError) (abort bool) {
+					errors = append(errors, err)
+					return
+				},
+			)
+
+			ok := assertEqualsExpectedOrRerecordVerificationErrors(
+				t,
+				errors,
+				pth,
+				expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestSpecialItemOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"SpecialItem",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.SpecialItemFromJsonable(
+			jsonable,
+		)
+		if deseriaErr != nil {
+			t.Fatalf(
+				"Unexpected deserialization error from %s: %s",
+				pth, deseriaErr.Error(),
+			)
+			return
+		}
+
+		var errors []*ourverification.VerificationError
+		ourverification.Verify(
+			deserialized,
+			func(veriErr *ourverification.VerificationError) (abort bool) {
+				errors = append(errors, veriErr)
+				return
+			},
+		)
+
+		ok := assertNoVerificationErrors(
+			t,
+			deserialized,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSpecialItemFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Invalid",
+		"*",  // This asterisk represents the cause.
+		"SpecialItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"VerificationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".errors",
+			)
+
+			deserialized, deseriaErr := ourjsonization.SpecialItemFromJsonable(
+				jsonable,
+			)
+			if deseriaErr != nil {
+				t.Fatalf(
+					"Unexpected deserialization error from %s: %s",
+					pth, deseriaErr.Error(),
+				)
+				return
+			}
+
+			var errors []*ourverification.VerificationError
+			ourverification.Verify(
+				deserialized,
+				func(err *ourverification.VerificationError) (abort bool) {
+					errors = append(errors, err)
+					return
+				},
+			)
+
+			ok := assertEqualsExpectedOrRerecordVerificationErrors(
+				t,
+				errors,
+				pth,
+				expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestContainerOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"Container",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.ContainerFromJsonable(
+			jsonable,
+		)
+		if deseriaErr != nil {
+			t.Fatalf(
+				"Unexpected deserialization error from %s: %s",
+				pth, deseriaErr.Error(),
+			)
+			return
+		}
+
+		var errors []*ourverification.VerificationError
+		ourverification.Verify(
+			deserialized,
+			func(veriErr *ourverification.VerificationError) (abort bool) {
+				errors = append(errors, veriErr)
+				return
+			},
+		)
+
+		ok := assertNoVerificationErrors(
+			t,
+			deserialized,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestContainerFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Invalid",
+		"*",  // This asterisk represents the cause.
+		"Container",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"VerificationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".errors",
+			)
+
+			deserialized, deseriaErr := ourjsonization.ContainerFromJsonable(
+				jsonable,
+			)
+			if deseriaErr != nil {
+				t.Fatalf(
+					"Unexpected deserialization error from %s: %s",
+					pth, deseriaErr.Error(),
+				)
+				return
+			}
+
+			var errors []*ourverification.VerificationError
+			ourverification.Verify(
+				deserialized,
+				func(err *ourverification.VerificationError) (abort bool) {
+					errors = append(errors, err)
+					return
+				},
+			)
+
+			ok := assertEqualsExpectedOrRerecordVerificationErrors(
+				t,
+				errors,
+				pth,
+				expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestWrapperOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Json",
+			"Expected",
+			"Wrapper",
+		),
+		".json",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		jsonable := ourtesting.MustReadJsonable(
+			pth,
+		)
+
+		deserialized, deseriaErr := ourjsonization.WrapperFromJsonable(
+			jsonable,
+		)
+		if deseriaErr != nil {
+			t.Fatalf(
+				"Unexpected deserialization error from %s: %s",
+				pth, deseriaErr.Error(),
+			)
+			return
+		}
+
+		var errors []*ourverification.VerificationError
+		ourverification.Verify(
+			deserialized,
+			func(veriErr *ourverification.VerificationError) (abort bool) {
+				errors = append(errors, veriErr)
+				return
+			},
+		)
+
+		ok := assertNoVerificationErrors(
+			t,
+			deserialized,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestWrapperFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Json",
+		"Unexpected",
+		"Invalid",
+		"*",  // This asterisk represents the cause.
+		"Wrapper",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".json",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			jsonable := ourtesting.MustReadJsonable(
+				pth,
+			)
+
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"VerificationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".errors",
+			)
+
+			deserialized, deseriaErr := ourjsonization.WrapperFromJsonable(
+				jsonable,
+			)
+			if deseriaErr != nil {
+				t.Fatalf(
+					"Unexpected deserialization error from %s: %s",
+					pth, deseriaErr.Error(),
+				)
+				return
+			}
+
+			var errors []*ourverification.VerificationError
+			ourverification.Verify(
+				deserialized,
+				func(err *ourverification.VerificationError) (abort bool) {
+					errors = append(errors, err)
+					return
+				},
+			)
+
+			ok := assertEqualsExpectedOrRerecordVerificationErrors(
+				t,
+				errors,
+				pth,
+				expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/verification.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/verification.go
new file mode 100644
index 000000000..8da690bd3
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/verification/verification.go
@@ -0,0 +1,863 @@
+// Package verification allows you to verify model instances.
+//
+// The main function is [Verify].
+//
+// Other verification functions (`Verify*`) are left for modularity, in case you want
+// to be explicit about the typing in your code. However, in the large majority of
+// the cases, you only want to call [Verify].
+package verification
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	ourcommon "github.com/dummy-works/dummy/common"
+	ourreporting "github.com/dummy-works/dummy/reporting"
+	ourtypes "github.com/dummy-works/dummy/types"
+)
+
+// Represent a verification violation.
+//
+// Implements `error`.
+type VerificationError struct{
+	Path *ourreporting.Path
+	Message string
+}
+
+func newVerificationError(message string) *VerificationError {
+	return &VerificationError{
+		Path: &ourreporting.Path{},
+		Message: message,
+	}
+}
+
+func (ve *VerificationError) Error() string {
+	return fmt.Sprintf(
+		"%s: %s",
+		ve.PathString(),
+		ve.Message,
+	)
+}
+
+// Render the path as a string.
+func (ve *VerificationError) PathString() string {
+	return ourreporting.ToGolangPath(ve.Path)
+}
+
+// Check that the names of the items are unique.
+//
+// The items are a generic sequence, so the sequences of
+// the descendants of [ourtypes.IItem] can be passed without a copy.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func NamesAreUnique[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	var nameSet map[string]struct{} = make(map[string]struct{})
+	for _, item := range items {
+		if (
+			ourcommon.MapContains(
+				nameSet,
+				item.Name(),
+			)) {
+			return false
+		}
+		nameSet[item.Name()] = struct{}{}
+	}
+	return true
+}
+
+// Iterate over a generic sequence in a generator.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func NamesAreNonEmpty[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	return ourcommon.All(
+			func(item ItemsT) bool {
+				return ourcommon.LenStr(item.Name()) > 0
+			},
+			items,
+		)
+}
+
+// Narrow the items of a generic sequence in a generator.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func SomeSpecialItemHasLevel[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	return ourcommon.Some(
+			func(item ItemsT) bool {
+				return ourtypes.IsSpecialItem(item) &&
+					any(item).(ourtypes.ISpecialItem).Level() > 0
+			},
+			items,
+		)
+}
+
+// Index a generic sequence, and narrow the item.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func FirstIsSpecial[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	if len(items) == 0 {
+		return false
+	}
+	first := items[0]
+	if ourtypes.IsSpecialItem(first) {
+		return any(first).(ourtypes.ISpecialItem).Level() > 0
+	}
+	return false
+}
+
+// Check that the nicknames of the items are unique, if specified.
+//
+// This mirrors the body of `ID_shorts_are_unique` in aas-core-meta V3.2:
+// a local variable takes an optional property of an item of a generic sequence,
+// and the loop continues if it is None.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func NicknamesAreUnique[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	var nicknameSet map[string]struct{} = make(map[string]struct{})
+	for _, item := range items {
+		nickname := item.Nickname()
+		if nickname == nil {
+			continue
+		}
+		if (
+			ourcommon.MapContains(
+				nicknameSet,
+				*nickname,
+			)) {
+			return false
+		}
+		nicknameSet[*nickname] = struct{}{}
+	}
+	return true
+}
+
+// Narrow the loop variable over a generic sequence in a for-loop.
+//
+// The loop variable is of the type parameter in Go, so the down-cast needs to
+// go through `any(...)`, and of the template parameter in C++.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func LevelsOfSpecialItemsArePositive[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	for _, item := range items {
+		if ourtypes.IsSpecialItem(item) {
+			if any(item).(ourtypes.ISpecialItem).Level() <= 0 {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Narrow an immutable local variable which holds an item of a generic sequence.
+//
+// In contrast to [FirstIsSpecial], the local variable is annotated, so
+// it is of the parent class instead of the type parameter. Hence, Go down-casts
+// it without `any(...)`, and C++ binds the item to a constant reference to
+// the shared pointer of the parent class.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func LastIsSpecial[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	if len(items) == 0 {
+		return false
+	}
+	var last ourtypes.IItem = items[len(items) - 1]
+	if ourtypes.IsSpecialItem(last) {
+		return last.(ourtypes.ISpecialItem).Level() > 0
+	}
+	return false
+}
+
+// Mix two generic sequences with an argument which is not generic.
+//
+// The names must differ, except for the sharedName, which may repeat.
+//
+// Go declares two type parameters, and C++ two template parameters. The nested
+// generators iterate over two different generic sequences, so their variables
+// are of two different type parameters.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+//
+// The items of the argument otherItems are of the type parameter OtherItemsT instead of ourtypes.ISomeItem so that the slices of the descendants of ourtypes.ISomeItem can be passed without a copy, as the slices are invariant in Go.
+func NamesAreDisjoint[ItemsT ourtypes.IItem, OtherItemsT ourtypes.ISomeItem](
+	items []ItemsT,
+	otherItems []OtherItemsT,
+	sharedName string,
+) bool {
+	return ourcommon.All(
+			func(item ItemsT) bool {
+				return ourcommon.All(
+						func(otherItem OtherItemsT) bool {
+							return item.Name() != otherItem.Name() ||
+								item.Name() == sharedName
+						},
+						otherItems,
+					)
+			},
+			items,
+		)
+}
+
+// Use the immutable aliases of the generic sequences.
+//
+// An immutable alias of the very same type shares the type annotation of
+// the aliased generic sequence, so it is a generic sequence itself. Go declares
+// the alias with the type parameter, C++ with the template parameter, while C#
+// and Java infer its type with `var`. The `alias_of_alias` aliases an alias,
+// and the `optional_alias` aliases an optional generic sequence.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+//
+// The items of the argument optionalItems are of the type parameter OptionalItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func AliasedNamesAreUnique[ItemsT ourtypes.IItem, OptionalItemsT ourtypes.IItem](
+	items []ItemsT,
+	optionalItems []OptionalItemsT,
+) bool {
+	var alias []ItemsT = items
+	var aliasOfAlias []ItemsT = alias
+	var optionalAlias []OptionalItemsT = optionalItems
+	for _, item := range alias {
+		if ourtypes.IsSpecialItem(item) {
+			if any(item).(ourtypes.ISpecialItem).Level() <= 0 {
+				return false
+			}
+		}
+	}
+	return ourcommon.All(
+			func(item ItemsT) bool {
+				return ourcommon.LenStr(item.Name()) > 0
+			},
+			aliasOfAlias,
+		) &&
+		NamesAreUnique(aliasOfAlias) &&
+		OptionalNamesAreUnique(optionalAlias) &&
+		((optionalAlias == nil) ||
+		NamesAreUnique(optionalAlias))
+}
+
+// Look up an instance of a descendant in a generic sequence.
+//
+// Go compares the instances as `any`'s, as the items are of the type parameter,
+// and C++ converts the member to the shared pointer of [ourtypes.IItem] so that
+// the raw pointers are comparable for any template parameter.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func ContainsSomeItem[ItemsT ourtypes.IItem](
+	someItem ourtypes.ISomeItem,
+	items []ItemsT,
+) bool {
+	return ourcommon.SliceContainsInstance(
+			items,
+			someItem,
+		)
+}
+
+// Look up the items of a generic sequence in another generic sequence.
+//
+// The member and the items are of two different type parameters.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+//
+// The items of the argument otherItems are of the type parameter OtherItemsT instead of ourtypes.ISomeItem so that the slices of the descendants of ourtypes.ISomeItem can be passed without a copy, as the slices are invariant in Go.
+func ItemsOverlap[ItemsT ourtypes.IItem, OtherItemsT ourtypes.ISomeItem](
+	items []ItemsT,
+	otherItems []OtherItemsT,
+) bool {
+	return ourcommon.Some(
+			func(otherItem OtherItemsT) bool {
+				return ourcommon.SliceContainsInstance(
+						items,
+						otherItem,
+					)
+			},
+			otherItems,
+		)
+}
+
+// Look up an instance in a sequence which is not generic.
+//
+// The [ourtypes.ISpecialItem] has no descendants, so the items are not
+// a generic sequence, but Go still compares the instances as `any`'s.
+func ContainsSpecialItem(
+	specialItem ourtypes.ISpecialItem,
+	items []ourtypes.ISpecialItem,
+) bool {
+	return ourcommon.SliceContainsInstance(
+			items,
+			specialItem,
+		)
+}
+
+// Pass the local variables on to generic sequences.
+//
+// The `some_items` is a read-only alias without an annotation, while
+// the `all_some_items` is an immutable local variable declared with
+// `Final[...]`. Both hold the sequences of [ourtypes.ISomeItem], and are passed
+// on to the generic sequences of [ourtypes.IItem], required as well as optional.
+func ContainerNamesAreUnique(
+	container ourtypes.IContainer,
+) bool {
+	someItems := container.SomeItems()
+	var allSomeItems []ourtypes.ISomeItem = container.SomeItems()
+	return NamesAreUnique(someItems) &&
+		NamesAreUnique(allSomeItems) &&
+		OptionalNamesAreUnique(allSomeItems)
+}
+
+// Pass an optional generic sequence on to a generic sequence.
+//
+// The items of the argument items are of the type parameter ItemsT instead of ourtypes.IItem so that the slices of the descendants of ourtypes.IItem can be passed without a copy, as the slices are invariant in Go.
+func OptionalNamesAreUnique[ItemsT ourtypes.IItem](
+	items []ItemsT,
+) bool {
+	return (items == nil) ||
+		NamesAreUnique(items)
+}
+
+// Pass the generic sequences of the descendants on.
+//
+// The someItems are passed on as a required and as an optional
+// sequence of the parent class, while the specialItems are passed on
+// as an optional sequence and, once narrowed, as a required sequence of the parent
+// class of the parent class.
+//
+// The items of the argument someItems are of the type parameter SomeItemsT instead of ourtypes.ISomeItem so that the slices of the descendants of ourtypes.ISomeItem can be passed without a copy, as the slices are invariant in Go.
+func SomeNamesAreUnique[SomeItemsT ourtypes.ISomeItem](
+	someItems []SomeItemsT,
+	specialItems []ourtypes.ISpecialItem,
+) bool {
+	return NamesAreUnique(someItems) &&
+		OptionalNamesAreUnique(someItems) &&
+		OptionalNamesAreUnique(specialItems) &&
+		OptionalNamesAreUnique([]ourtypes.IItem(nil)) &&
+		((specialItems == nil) ||
+		NamesAreUnique(specialItems))
+}
+
+// Check that the levels are positive.
+//
+// The [ourtypes.ISpecialItem] has no descendants, so the items are not
+// a generic sequence.
+func LevelsArePositive(
+	items []ourtypes.ISpecialItem,
+) bool {
+	return ourcommon.All(
+			func(item ourtypes.ISpecialItem) bool {
+				return item.Level() > 0
+			},
+			items,
+		)
+}
+
+// Verify `that` instance of [ourtypes.ISomeItem].
+//
+// You have to supply the callback `onError` to iterate over the errors.
+// If `onError` returns abort `true`, this function will abort
+// further verification as well, and return abort `true`. Otherwise,
+// abort `false` is returned.
+func VerifySomeItem(
+	that ourtypes.ISomeItem,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	abort = false
+
+	// No verification has been defined for ISomeItem.
+
+	return
+}
+
+// Verify `that` instance of [ourtypes.ISpecialItem].
+//
+// You have to supply the callback `onError` to iterate over the errors.
+// If `onError` returns abort `true`, this function will abort
+// further verification as well, and return abort `true`. Otherwise,
+// abort `false` is returned.
+func VerifySpecialItem(
+	that ourtypes.ISpecialItem,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	abort = false
+
+	// No verification has been defined for ISpecialItem.
+
+	return
+}
+
+// Verify `that` instance of [ourtypes.IContainer].
+//
+// You have to supply the callback `onError` to iterate over the errors.
+// If `onError` returns abort `true`, this function will abort
+// further verification as well, and return abort `true`. Otherwise,
+// abort `false` is returned.
+func VerifyContainer(
+	that ourtypes.IContainer,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	abort = false
+
+	if !(
+		!(that.SpecialItems() != nil) ||
+		ourcommon.All(
+			func(specialItem ourtypes.ISpecialItem) bool {
+				return ContainsSpecialItem(
+						specialItem,
+						that.SpecialItems(),
+					)
+			},
+			that.SpecialItems(),
+		)) {
+		abort = onError(
+			newVerificationError(
+				"Each special item must be among the special items.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		len(that.SomeItems()) == 0 ||
+		ItemsOverlap(that.Items(), that.SomeItems())) {
+		abort = onError(
+			newVerificationError(
+				"If there are some items, they must overlap with the items.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		ourcommon.All(
+			func(someItem ourtypes.ISomeItem) bool {
+				return ContainsSomeItem(someItem, that.Items())
+			},
+			that.SomeItems(),
+		)) {
+		abort = onError(
+			newVerificationError(
+				"Some items must be among the items.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		AliasedNamesAreUnique(
+			that.SomeItems(),
+			that.SpecialItems(),
+		)) {
+		abort = onError(
+			newVerificationError(
+				"Names of some items and of special items must be unique " +
+				"through aliases.",
+			),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		NamesAreDisjoint(
+			that.Items(),
+			that.SomeItems(),
+			"x",
+		)) {
+		abort = onError(
+			newVerificationError(
+				"Names of the items and of some items must be disjoint.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		!SomeSpecialItemHasLevel(that.Items()) ||
+		LastIsSpecial(that.Items())) {
+		abort = onError(
+			newVerificationError(
+				"If there is a special item with level, the last item must " +
+				"be special.",
+			),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !LevelsOfSpecialItemsArePositive(that.Items()) {
+		abort = onError(
+			newVerificationError(
+				"Levels of the special items among the items must be " +
+				"positive.",
+			),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !NicknamesAreUnique(that.SomeItems()) {
+		abort = onError(
+			newVerificationError(
+				"Nicknames of some items must be unique.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		that.CountItems(that.Items()) == int64(len(that.Items()))) {
+		abort = onError(
+			newVerificationError(
+				"Count of the items must match the number of the items.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !OptionalNamesAreUnique(that.SpecialItems()) {
+		abort = onError(
+			newVerificationError(
+				"Names of the special items must be unique.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		!(that.SpecialItems() != nil) ||
+		FirstIsSpecial(that.SpecialItems())) {
+		abort = onError(
+			newVerificationError(
+				"The first special item must be special.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		!(that.SpecialItems() != nil) ||
+		LevelsArePositive(that.SpecialItems())) {
+		abort = onError(
+			newVerificationError(
+				"Levels of the special items must be positive.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		!SomeSpecialItemHasLevel(that.Items()) ||
+		FirstIsSpecial(that.Items())) {
+		abort = onError(
+			newVerificationError(
+				"If there is a special item with level, the first item must " +
+				"be special.",
+			),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !NamesAreNonEmpty(that.SomeItems()) {
+		abort = onError(
+			newVerificationError(
+				"Names of some items must be non-empty.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !(
+		SomeNamesAreUnique(
+			that.SomeItems(),
+			that.SpecialItems(),
+		)) {
+		abort = onError(
+			newVerificationError(
+				"Names of some items and of special items must be unique.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if !NamesAreUnique(that.Items()) {
+		abort = onError(
+			newVerificationError(
+				"Names of the items must be unique.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if that.Items() == nil {
+		abort = onError(
+			newVerificationError(
+				"Required property not set: Items",
+			),
+		)
+		if abort {
+			return
+		}
+	} else {
+		abort = verifyListOf_IItem(
+			that.Items(),
+			func(err *VerificationError) bool {
+				err.Path.PrependName(
+					&ourreporting.NameSegment{
+						Name: "Items",
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	if that.SomeItems() == nil {
+		abort = onError(
+			newVerificationError(
+				"Required property not set: SomeItems",
+			),
+		)
+		if abort {
+			return
+		}
+	} else {
+		abort = verifyListOf_ISomeItem(
+			that.SomeItems(),
+			func(err *VerificationError) bool {
+				err.Path.PrependName(
+					&ourreporting.NameSegment{
+						Name: "SomeItems",
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	if that.SpecialItems() != nil {
+		abort = verifyListOf_ISpecialItem(
+			that.SpecialItems(),
+			func(err *VerificationError) bool {
+				err.Path.PrependName(
+					&ourreporting.NameSegment{
+						Name: "SpecialItems",
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Verify `that` instance of [ourtypes.IWrapper].
+//
+// You have to supply the callback `onError` to iterate over the errors.
+// If `onError` returns abort `true`, this function will abort
+// further verification as well, and return abort `true`. Otherwise,
+// abort `false` is returned.
+func VerifyWrapper(
+	that ourtypes.IWrapper,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	abort = false
+
+	if !ContainerNamesAreUnique(that.Container()) {
+		abort = onError(
+			newVerificationError(
+				"Names of some items of the container must be unique.",),
+		)
+		if abort {
+			return
+		}
+	}
+
+	if that.Container() == nil {
+		abort = onError(
+			newVerificationError(
+				"Required property not set: Container",
+			),
+		)
+		if abort {
+			return
+		}
+	} else {
+		abort = Verify(
+			that.Container(),
+			func(err *VerificationError) bool {
+				err.Path.PrependName(
+					&ourreporting.NameSegment{
+						Name: "Container",
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Verify the items of `that` recursively.
+func verifyListOf_IItem(
+	that []ourtypes.IItem,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	for i, item := range that {
+		abort = Verify(
+			item,
+			func(err *VerificationError) bool {
+				err.Path.PrependIndex(
+					&ourreporting.IndexSegment{
+						Index: i,
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Verify the items of `that` recursively.
+func verifyListOf_ISomeItem(
+	that []ourtypes.ISomeItem,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	for i, item := range that {
+		abort = Verify(
+			item,
+			func(err *VerificationError) bool {
+				err.Path.PrependIndex(
+					&ourreporting.IndexSegment{
+						Index: i,
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Verify the items of `that` recursively.
+func verifyListOf_ISpecialItem(
+	that []ourtypes.ISpecialItem,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	for i, item := range that {
+		abort = Verify(
+			item,
+			func(err *VerificationError) bool {
+				err.Path.PrependIndex(
+					&ourreporting.IndexSegment{
+						Index: i,
+					},
+				)
+				return onError(err)
+			},
+		)
+		if abort {
+			return
+		}
+	}
+
+	return
+}
+
+// Verify ``that`` instance.
+//
+// You have to supply the callback `onError` to iterate over the errors.
+// If `onError` returns abort `true`, this function will abort
+// further verification as well, and return abort `true`. Otherwise,
+// abort `false` is returned.
+func Verify(
+	that ourtypes.IClass,
+	onError func(*VerificationError) bool,
+) (abort bool) {
+	modelType := that.ModelType()
+	switch modelType {
+	case ourtypes.ModelTypeSomeItem:
+		abort = VerifySomeItem(
+			that.(ourtypes.ISomeItem),
+			onError,
+		)
+	case ourtypes.ModelTypeSpecialItem:
+		abort = VerifySpecialItem(
+			that.(ourtypes.ISpecialItem),
+			onError,
+		)
+	case ourtypes.ModelTypeContainer:
+		abort = VerifyContainer(
+			that.(ourtypes.IContainer),
+			onError,
+		)
+	case ourtypes.ModelTypeWrapper:
+		abort = VerifyWrapper(
+			that.(ourtypes.IWrapper),
+			onError,
+		)
+	default:
+		abort = onError(
+			newVerificationError(
+				fmt.Sprintf(
+					"Unexpected model type literal: %v",
+					modelType,
+				),
+			),
+		)
+	}
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/common_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/common_test.go
new file mode 100644
index 000000000..f092c4c7d
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/common_test.go
@@ -0,0 +1,296 @@
+package xmlization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"testing"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourxmlization "github.com/dummy-works/dummy/xmlization"
+)
+
+// Assert that there is no de-serialization error when de-serializing
+// from `source`.
+func assertNoDeserializationError(
+	t *testing.T,
+	err error,
+	source string,
+) (ok bool) {
+	ok = true
+	if err != nil {
+		ok = false
+		t.Fatalf(
+			"Expected no de-serialization error from %s, but got: %s",
+			source, err.Error(),
+		)
+		return
+	}
+	return
+}
+
+// Assert that there is no serialization error when serializing the instance
+// originally coming from `source`.
+func assertNoSerializationError(
+	t *testing.T,
+	err error,
+	source string,
+) (ok bool) {
+	ok = true
+	if err != nil {
+		ok = false
+		t.Fatalf(
+			"Expected no serialization error when serializing "+
+				"the instance obtained from %s, but got: %s",
+			source, err.Error(),
+		)
+		return
+	}
+	return
+}
+
+// NOTE (mristin):
+// Currently, Go does not support self-closing tags,
+// see: https://github.com/golang/go/issues/21399.
+// We apply the following hack to make the tags self-closing even if they are not.
+// This is unsafe in general, but works OK for the limited set of test data that we are
+// here dealing with.
+//
+// The code has been taken from: https://github.com/golang/go/issues/21399#issuecomment-1342730174
+
+// NOTE (mristin):
+// The opening tag, tag name plus an optional attribute list (*e.g.*,
+// ``xmlns="..."`` on a root element), is captured in the first (and only)
+// submatch group so that we do not lose any attributes when we force
+// the tag to be self-closing below. The attribute list must not end with
+// a slash, as we would otherwise match an already self-closing tag followed
+// by the closing tag of its parent, *e.g.*, ``<someBytes /></something>``.
+var emptyTagRe = regexp.MustCompile(`<(\w+(?:\s[^>]*[^/>])?)></\w+>`)
+
+func forceSelfClosingTags(text string) string {
+	b := []byte(text)
+	emptyTagIdxs := emptyTagRe.FindAllSubmatchIndex(b, -1)
+
+	if len(emptyTagIdxs) == 0 {
+		return text
+	}
+
+	// NOTE (mristin):
+	// The matches are walked in order, and the pieces of `b` between them are
+	// copied over as they are. Mind that `nb` starts out empty and that `b` is
+	// only ever *read*: an earlier version appended into `b[0:idx[0]]`, which
+	// writes into `b`'s own backing array, so a document with more than one
+	// empty tag came out garbled -- every turn of the loop then indexed into
+	// a `b` which the previous turn had already overwritten.
+	var nb []byte
+	previous := 0
+
+	for _, idx := range emptyTagIdxs {
+		// Copy everything since the previous match, then the tag itself --
+		// its name and its attributes -- as a self-closing one.
+		nb = append(nb, b[previous:idx[0]]...)
+		nb = append(nb, fmt.Sprintf("<%s/>", b[idx[2]:idx[3]])...)
+
+		previous = idx[1]
+	}
+
+	// Finally, copy everything after the last match.
+	nb = append(nb, b[previous:]...)
+
+	return string(nb)
+}
+
+var whitespaceBetweenTagsRe = regexp.MustCompile(`>\s+<`)
+
+// Remove all whitespace (including newlines, tabs, and spaces) between XML tags
+// without parsing the XML.
+func removeWhitespaceBetweenTags(text string) string {
+	return whitespaceBetweenTagsRe.ReplaceAllString(text, "><")
+}
+
+var whitespaceBeforeAngleBracketsRe = regexp.MustCompile(`\s+>`)
+var whitespaceBeforeSelfClosingRe = regexp.MustCompile(`\s+/>`)
+var whitespaceAfterAngleBracketsRe = regexp.MustCompile(`<\s+`)
+
+// Remove any whitespace before `>` and `/>` or after `<`
+func removeWhitespaceWithinTags(text string) string {
+	result := text
+	result = whitespaceBeforeAngleBracketsRe.ReplaceAllString(result, ">")
+	result = whitespaceBeforeSelfClosingRe.ReplaceAllString(result, "/>")
+	result = whitespaceAfterAngleBracketsRe.ReplaceAllString(result, "<")
+	return result
+}
+
+// Assert that the serialization `other`, as XML document, equals the original
+//
+//	XML document `that` read from the `source`.
+func assertSerializationEqualsDeserialization(
+	t *testing.T,
+	that string,
+	other string,
+	source string,
+) (ok bool) {
+	ok = true
+
+	// Remove carriers to avoid problems between Windows, Posix and MacOS
+	canonicalThat := strings.ReplaceAll(that, "\r", "")
+	canonicalOther := strings.ReplaceAll(other, "\r", "")
+
+	canonicalThat = strings.TrimSpace(canonicalThat)
+	canonicalOther = strings.TrimSpace(canonicalOther)
+
+	canonicalThat = forceSelfClosingTags(canonicalThat)
+	canonicalOther = forceSelfClosingTags(canonicalOther)
+
+	// NOTE (mristin):
+	// The following hack is SUPER ugly and unsafe! However, it works. Given Go's
+	// limited support for XML, we gave up on a safer approach :(. We tested
+	// the following approaches before applying this hack:
+	//  * A round-trip over `encoding/xml`. Failed due to
+	//    https://github.com/golang/go/issues/13400.
+	//  * Using `aqwari.net/xml/xmltree`. Failed as the special characters in the
+	//    element content still has not been de-escaped or consistently escaped in
+	//    a round trip.
+
+	canonicalThat = strings.ReplaceAll(canonicalThat, "'", "&#39;")
+	canonicalOther = strings.ReplaceAll(canonicalOther, "'", "&#39;")
+
+	canonicalThat = removeWhitespaceBetweenTags(canonicalThat)
+	canonicalOther = removeWhitespaceBetweenTags(canonicalOther)
+
+	canonicalThat = removeWhitespaceWithinTags(canonicalThat)
+	canonicalOther = removeWhitespaceWithinTags(canonicalOther)
+
+	thatLines := strings.Split(canonicalThat, "\n")
+	otherLines := strings.Split(canonicalOther, "\n")
+
+	if canonicalThat != canonicalOther {
+		b := new(strings.Builder)
+		minLines := len(thatLines)
+		if minLines > len(otherLines) {
+			minLines = len(otherLines)
+		}
+		for i := 0; i < minLines; i++ {
+			if thatLines[i] == otherLines[i] {
+				b.WriteString(fmt.Sprintf("           %s\n", thatLines[i]))
+			} else {
+				b.WriteString(fmt.Sprintf("ORIGINAL   %s\n", thatLines[i]))
+				b.WriteString(fmt.Sprintf("SERIALIZED %s\n", otherLines[i]))
+				break
+			}
+		}
+
+		ok = false
+		t.Fatalf(
+			"The canonicalized XML serialization of the de-serialized instance "+
+				"from %s does not equal the canonicalized original XML document:\n"+
+				"%s",
+			source, b.String(),
+		)
+		return
+	}
+
+	return
+}
+
+// Assert that there is a de-serialization error.
+//
+// If [ourtesting.RecordMode] is set, the de-serialization error is re-recorded
+// to `expectedPth`. Otherwise, the error is compared against the golden file
+// `expectedPth`.
+func assertIsDeserializationErrorAndEqualsExpectedOrRecord(
+	t *testing.T,
+	err error,
+	source string,
+	expectedPth string,
+) (ok bool) {
+	ok = true
+
+	if err == nil {
+		ok = false
+		t.Fatalf("De-serialization error expected from %s, but got none", source)
+		return
+	}
+
+	deseriaErr, is := err.(*ourxmlization.DeserializationError)
+	if !is {
+		ok = false
+		t.Fatalf(
+			"Expected a de-serialization error, "+
+				"but got an error of type %T from %s: %v",
+			err, source, err,
+		)
+		return
+	}
+
+	// Add a new line for POSIX systems.
+	got := deseriaErr.Error() + "\n"
+
+	if ourtesting.RecordMode {
+		parent := filepath.Dir(expectedPth)
+		err := os.MkdirAll(parent, os.ModePerm)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to create the directory %s: %s", parent, err.Error(),
+				),
+			)
+		}
+
+		err = os.WriteFile(expectedPth, []byte(got), 0644)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to write to the file %s: %s", expectedPth, err.Error(),
+				),
+			)
+		}
+	} else {
+		_, err := os.Stat(expectedPth)
+		if err != nil {
+			ok = false
+			t.Fatalf(
+				"Failed to stat the file %s: %s; if the file does not exist, "+
+					"you probably want to record the test data by "+
+					"setting the environment variable %s",
+				expectedPth, err.Error(), ourtesting.RecordModeEnvironmentVariableName,
+			)
+			return
+		}
+
+		bb, err := os.ReadFile(expectedPth)
+		if err != nil {
+			panic(
+				fmt.Sprintf(
+					"Failed to read from file %s: %s", expectedPth, err.Error(),
+				),
+			)
+		}
+
+		expected := string(bb)
+
+		// NOTE (mristin):
+		// Git automatically strips and adds `\r`, so we have to remove it here
+		// to obtain a canonical text.
+		expected = strings.Replace(expected, "\r", "", -1)
+
+		if expected != got {
+			ok = false
+			t.Fatalf(
+				"What we got differs from the expected in %s. "+
+					"We got:\n%s\nWe expected:\n%s",
+				expectedPth, got, expected,
+			)
+			return
+		}
+	}
+
+	return
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/concrete_classes_test.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/concrete_classes_test.go
new file mode 100644
index 000000000..2b31e99cd
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/test/concrete_classes_test.go
@@ -0,0 +1,582 @@
+package xmlization_test
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"bytes"
+	"path/filepath"
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+	"testing"
+	"encoding/xml"
+	ourtesting "github.com/dummy-works/dummy/ourtesting"
+	ourtypes "github.com/dummy-works/dummy/types"
+	ourxmlization "github.com/dummy-works/dummy/xmlization"
+)
+
+func TestSomeItemRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Xml",
+			"Expected",
+			"someItem",
+		),
+		".xml",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		bb, err := os.ReadFile(pth)
+		if err != nil {
+			t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+			return
+		}
+		text := string(bb)
+
+		decoder := xml.NewDecoder(strings.NewReader(text))
+
+		deserialized, deseriaErr := ourxmlization.Unmarshal(decoder)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		if _, ok := deserialized.(ourtypes.ISomeItem); !ok {
+			t.Fatalf(
+				"Expected an instance of ISomeItem, "+
+					"but got %T: %v",
+				deserialized, deserialized,
+			)
+			return
+		}
+
+		buf := &bytes.Buffer{}
+		encoder := xml.NewEncoder(buf)
+		encoder.Indent("", "\t")
+
+		seriaErr := ourxmlization.Marshal(encoder, deserialized, true)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		roundTrip := string(buf.Bytes())
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			text,
+			roundTrip,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSomeItemDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Xml",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"someItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".xml",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			bb, err := os.ReadFile(pth)
+			if err != nil {
+				t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+				return
+			}
+			text := string(bb)
+
+			decoder := xml.NewDecoder(strings.NewReader(text))
+
+			_, deseriaErr := ourxmlization.Unmarshal(decoder)
+			ok := assertIsDeserializationErrorAndEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestSpecialItemRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Xml",
+			"Expected",
+			"specialItem",
+		),
+		".xml",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		bb, err := os.ReadFile(pth)
+		if err != nil {
+			t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+			return
+		}
+		text := string(bb)
+
+		decoder := xml.NewDecoder(strings.NewReader(text))
+
+		deserialized, deseriaErr := ourxmlization.Unmarshal(decoder)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		if _, ok := deserialized.(ourtypes.ISpecialItem); !ok {
+			t.Fatalf(
+				"Expected an instance of ISpecialItem, "+
+					"but got %T: %v",
+				deserialized, deserialized,
+			)
+			return
+		}
+
+		buf := &bytes.Buffer{}
+		encoder := xml.NewEncoder(buf)
+		encoder.Indent("", "\t")
+
+		seriaErr := ourxmlization.Marshal(encoder, deserialized, true)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		roundTrip := string(buf.Bytes())
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			text,
+			roundTrip,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestSpecialItemDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Xml",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"specialItem",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".xml",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			bb, err := os.ReadFile(pth)
+			if err != nil {
+				t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+				return
+			}
+			text := string(bb)
+
+			decoder := xml.NewDecoder(strings.NewReader(text))
+
+			_, deseriaErr := ourxmlization.Unmarshal(decoder)
+			ok := assertIsDeserializationErrorAndEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestContainerRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Xml",
+			"Expected",
+			"container",
+		),
+		".xml",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		bb, err := os.ReadFile(pth)
+		if err != nil {
+			t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+			return
+		}
+		text := string(bb)
+
+		decoder := xml.NewDecoder(strings.NewReader(text))
+
+		deserialized, deseriaErr := ourxmlization.Unmarshal(decoder)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		if _, ok := deserialized.(ourtypes.IContainer); !ok {
+			t.Fatalf(
+				"Expected an instance of IContainer, "+
+					"but got %T: %v",
+				deserialized, deserialized,
+			)
+			return
+		}
+
+		buf := &bytes.Buffer{}
+		encoder := xml.NewEncoder(buf)
+		encoder.Indent("", "\t")
+
+		seriaErr := ourxmlization.Marshal(encoder, deserialized, true)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		roundTrip := string(buf.Bytes())
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			text,
+			roundTrip,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestContainerDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Xml",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"container",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".xml",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			bb, err := os.ReadFile(pth)
+			if err != nil {
+				t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+				return
+			}
+			text := string(bb)
+
+			decoder := xml.NewDecoder(strings.NewReader(text))
+
+			_, deseriaErr := ourxmlization.Unmarshal(decoder)
+			ok := assertIsDeserializationErrorAndEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestWrapperRoundTripOK(t *testing.T) {
+	pths := ourtesting.FindFilesBySuffixRecursively(
+		filepath.Join(
+			ourtesting.TestDataDir,
+			"Xml",
+			"Expected",
+			"wrapper",
+		),
+		".xml",
+	)
+	sort.Strings(pths)
+
+	for _, pth := range pths {
+		bb, err := os.ReadFile(pth)
+		if err != nil {
+			t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+			return
+		}
+		text := string(bb)
+
+		decoder := xml.NewDecoder(strings.NewReader(text))
+
+		deserialized, deseriaErr := ourxmlization.Unmarshal(decoder)
+		ok := assertNoDeserializationError(t, deseriaErr, pth)
+		if !ok {
+			return
+		}
+
+		if _, ok := deserialized.(ourtypes.IWrapper); !ok {
+			t.Fatalf(
+				"Expected an instance of IWrapper, "+
+					"but got %T: %v",
+				deserialized, deserialized,
+			)
+			return
+		}
+
+		buf := &bytes.Buffer{}
+		encoder := xml.NewEncoder(buf)
+		encoder.Indent("", "\t")
+
+		seriaErr := ourxmlization.Marshal(encoder, deserialized, true)
+		ok = assertNoSerializationError(t, seriaErr, pth)
+		if !ok {
+			return
+		}
+
+		roundTrip := string(buf.Bytes())
+
+		ok = assertSerializationEqualsDeserialization(
+			t,
+			text,
+			roundTrip,
+			pth,
+		)
+		if !ok {
+			return
+		}
+	}
+}
+
+func TestWrapperDeserializationFail(t *testing.T) {
+	pattern := filepath.Join(
+		ourtesting.TestDataDir,
+		"Xml",
+		"Unexpected",
+		"Unserializable",
+		"*",  // This asterisk represents the cause.
+		"wrapper",
+	)
+
+	causeDirs, err := filepath.Glob(pattern)
+	if err != nil {
+		panic(
+			fmt.Sprintf(
+				"Failed to find cause directories matching %s: %s",
+				pattern, err.Error(),
+			),
+		)
+	}
+
+	for _, causeDir := range causeDirs {
+		pths := ourtesting.FindFilesBySuffixRecursively(
+			causeDir,
+			".xml",
+		)
+		sort.Strings(pths)
+
+		for _, pth := range pths {
+			relPth, err := filepath.Rel(ourtesting.TestDataDir, pth)
+			if err != nil {
+				panic(
+					fmt.Sprintf(
+						"Failed to compute the relative path of %s to %s: %s",
+						ourtesting.TestDataDir, pth, err.Error(),
+					),
+				)
+			}
+
+			expectedPth := filepath.Join(
+				ourtesting.TestDataDir,
+				"DeserializationError",
+				filepath.Dir(relPth),
+				filepath.Base(relPth)+".error",
+			)
+
+			bb, err := os.ReadFile(pth)
+			if err != nil {
+				t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+				return
+			}
+			text := string(bb)
+
+			decoder := xml.NewDecoder(strings.NewReader(text))
+
+			_, deseriaErr := ourxmlization.Unmarshal(decoder)
+			ok := assertIsDeserializationErrorAndEqualsExpectedOrRecord(
+				t, deseriaErr, pth, expectedPth,
+			)
+			if !ok {
+				return
+			}
+		}
+	}
+}
+
+func TestDuplicatePropertyFails(t *testing.T) {
+	pth := filepath.Join(
+		ourtesting.TestDataDir,
+		"Xml",
+		"Expected",
+		"someItem",
+		"minimal.xml",
+	)
+
+	bb, err := os.ReadFile(pth)
+	if err != nil {
+		t.Fatalf("Failed to read the file %s: %s", pth, err.Error())
+	}
+
+	text := string(bb)
+
+	// We cut the element of the property out of the recorded example and put it in
+	// a second time, just before the closing tag of the instance.
+	start := strings.Index(text, "<name>")
+
+	var property string
+	if start >= 0 {
+		end := strings.Index(
+			text[start:], "</name>",
+		) + start
+		property = text[start : end+7]
+	} else {
+		// The element is written self-closing in the example, an empty list being
+		// the usual reason. We write that very element out ourselves.
+		property = "<name/>"
+	}
+
+	insertionIndex := strings.LastIndex(
+		text, "</someItem>",
+	)
+	if insertionIndex < 0 {
+		t.Fatalf(
+			"We expect the recorded example to contain the closing tag %s, "+
+				"but it does not: %s",
+			"</someItem>", pth,
+		)
+	}
+
+	brokenText := text[:insertionIndex] + property + text[insertionIndex:]
+
+	decoder := xml.NewDecoder(strings.NewReader(brokenText))
+
+	_, deseriaErr := ourxmlization.Unmarshal(decoder)
+	if deseriaErr == nil {
+		t.Fatalf(
+			"Expected a de-serialization error when the property %s is given twice, "+
+				"but got none",
+			"name",
+		)
+	}
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/xmlization.go b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/xmlization.go
new file mode 100644
index 000000000..4ec17495d
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/expected_output/xmlization/xmlization.go
@@ -0,0 +1,1221 @@
+// Package xmlization de/serializes model instances to and from XML.
+//
+// To de-serialize, call one of the `Unmarshal*` functions.
+//
+// To serialize, call the [Marshal] function.
+package xmlization
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import (
+	"encoding/xml"
+	"fmt"
+	ourreporting "github.com/dummy-works/dummy/reporting"
+	ourtypes "github.com/dummy-works/dummy/types"
+	xmlcommon "github.com/dummy-works/dummy/internal/xmlcommon"
+)
+
+// Namespace is the XML namespace in which all the elements live.
+const Namespace = xmlcommon.Namespace
+
+// region De-serialization
+
+// Represent an error during the de-serialization.
+//
+// Implements `error`.
+type DeserializationError = xmlcommon.DeserializationError
+
+// Report that the required property with the given `name` has not been observed.
+func missingProperty(name string) error {
+	return xmlcommon.NewDeserializationError(
+		fmt.Sprintf(
+			"The required property '%s' is missing",
+			name,
+		),
+	)
+}
+
+// Report that the property with the given `local` name has been observed more
+// than once.
+func duplicatePropertyError(local string) error {
+	return xmlcommon.NewDeserializationError(
+		fmt.Sprintf(
+			"Property %s occurred more than once",
+			local,
+		),
+	)
+}
+
+// Report that we got a start element with the `local` name, but expected a start
+// element with the `expectedLocal` name.
+func unexpectedStartElement(local string, expectedLocal string) error {
+	return xmlcommon.NewDeserializationError(
+		fmt.Sprintf(
+			"Expected a start element with local name %s, "+
+				"but got a start element with local name %s",
+			expectedLocal, local,
+		),
+	)
+}
+
+// Report that the start element with the `local` name does not discriminate any of
+// the alternatives of `expectedType`.
+func unexpectedDiscriminator(local string, expectedType string) error {
+	return xmlcommon.NewDeserializationError(
+		fmt.Sprintf(
+			"Unexpected start element %s as discriminator for %s",
+			local, expectedType,
+		),
+	)
+}
+
+// Report that we got an item delimited by a start element with the `local` name,
+// but expected the delimiter with the `expectedLocal` name.
+func unexpectedItemElement(local string, expectedLocal string) error {
+	return xmlcommon.NewDeserializationError(
+		fmt.Sprintf(
+			"Expected start element %s as an item delimiter, "+
+				"but got %s",
+			expectedLocal, local,
+		),
+	)
+}
+
+// Read a list of values as a sequence of XML elements.
+//
+// Every start element is considered to mark the start of an item serialization. We
+// stop the reading as soon as we encounter a non-start element.
+//
+// That last non-start element is returned as `next` element.
+//
+// An item is read with [xmlcommon.ReadElementDispatched], so `readItem` decides on its own
+// which local names it accepts. A list of instances and a list of scalars therefore
+// share this one function: an instance is discriminated by its own element name,
+// while a scalar is expected in an element named `v`.
+//
+// `T` is left unconstrained (instead of `ourtypes.IClass`) since this
+// function never invokes any `ourtypes.IClass` method on `T` -- this lets it
+// be reused for a list of scalars and for a list of a named union as well,
+// the latter being deliberately not an `ourtypes.IClass` itself.
+func readListOf[T any](
+	decoder *xml.Decoder,
+	current xml.Token,
+	readItem func(
+		aDecoder *xml.Decoder,
+		aCurrent xml.Token,
+		aLocal string,
+	) (value T, aNext xml.Token, anErr error),
+) (values []T, next xml.Token, err error) {
+	i := 0
+	for {
+		current, err = xmlcommon.SkipEmptyTextWhitespaceAndComments(decoder, current)
+		if err != nil {
+			return
+		}
+
+		if _, ok := current.(xml.StartElement); !ok {
+			break
+		}
+
+		var value T
+		var valueErr error
+		value, current, valueErr = xmlcommon.ReadElementDispatched(
+			decoder, current, readItem,
+		)
+		if valueErr != nil {
+			if deseriaErr, ok := valueErr.(*DeserializationError); ok {
+				deseriaErr.Path.PrependIndex(
+					&ourreporting.IndexSegment{Index: i},
+				)
+			}
+			err = valueErr
+			return
+		}
+
+		values = append(values, value)
+
+		i++
+	}
+
+	next = current
+	return
+}
+
+// Turn a just-read value into a pointer, so that it can be stored in an optional
+// property.
+//
+// An optional is represented as a pointer, so the value has to live outside the
+// caller's frame. This allocates exactly the one value that the caller would
+// otherwise allocate by taking the address of its own local variable, and no more.
+//
+// The arguments are the *results* of a read, not the reader itself. Go passes
+// a multi-valued call on as a complete argument list, so this composes with any read,
+// no matter how many arguments that read takes on its own --
+// `readOptional(xmlcommon.ReadTextAs_long(decoder, current))` just as much as
+// `readOptional(readTuple2(decoder, current, readAtV1_X, readAtV2_Y))`, which no
+// reader-taking signature could express, since the item readers of a tuple vary in
+// number and in type.
+func readOptional[T any](
+	value T,
+	current xml.Token,
+	err error,
+) (*T, xml.Token, error) {
+	if err != nil {
+		return nil, current, err
+	}
+
+	return &value, current, nil
+}
+
+// Advance to the next property of an instance serialized as a sequence of XML
+// elements, and return the `local` name of the corresponding start element.
+//
+// The resulting `next` token points to the content of that element.
+//
+// If there are no more properties, `ok` is false and `next` points to the token
+// which stopped the reading, be it a non-start element or [eof].
+//
+// `interfaceName` is only used for error reporting.
+func nextProperty(
+	decoder *xml.Decoder,
+	current xml.Token,
+	interfaceName string,
+) (local string, next xml.Token, ok bool, err error) {
+	current, err = xmlcommon.SkipEmptyTextWhitespaceAndComments(decoder, current)
+	if err != nil {
+		return
+	}
+
+	if _, isEOF := current.(xmlcommon.Eof); isEOF {
+		next = current
+		return
+	}
+
+	startElement, isStartElement := current.(xml.StartElement)
+	if !isStartElement {
+		if charData, isCharData := current.(xml.CharData); isCharData {
+			err = xmlcommon.NewDeserializationError(
+				fmt.Sprintf(
+					"Expected a sequence of XML elements representing properties "+
+						"of %s, but got text: %s",
+					interfaceName, string(charData),
+				),
+			)
+			return
+		}
+
+		next = current
+		return
+	}
+
+	local, err = xmlcommon.ExtractLocalNameFromStartElement(startElement)
+	if err != nil {
+		return
+	}
+
+	// Move the current to the content of the XML element
+	next, err = xmlcommon.ReadNext(decoder, current)
+	if err != nil {
+		return
+	}
+
+	ok = true
+	return
+}
+
+// Conclude the reading of the property delimited by the element with the `local`
+// name.
+//
+// If `valueErr` is set, report it in the context of that property. Otherwise,
+// consume the end element, so that the resulting `next` token points to the first
+// token just after it. An unexpected content in place of the end element, such as
+// a text or an excess element, is reported in the context of the property as well.
+func concludeProperty(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+	valueErr error,
+) (next xml.Token, err error) {
+	err = valueErr
+
+	if err == nil {
+		current, err = xmlcommon.SkipEmptyTextWhitespaceAndComments(decoder, current)
+	}
+
+	if err == nil {
+		err = xmlcommon.CheckEndElement(current, local)
+	}
+
+	if err != nil {
+		if deseriaErr, ok := err.(*DeserializationError); ok {
+			deseriaErr.Path.PrependName(
+				&ourreporting.NameSegment{Name: local},
+			)
+		}
+		return
+	}
+
+	next, err = xmlcommon.ReadNext(decoder, current)
+	return
+}
+
+// Wrap `readByLocal` so that its errors are reported at the element it reads.
+//
+// We use it where an instance of a class is its own element, at the root or
+// nested in a property, so that the path names the element of the instance,
+// *e.g.*, `someRoot/property/someClass/someProperty`, as in the other SDKs.
+// The items of a list and of a tuple are not wrapped, as their index already
+// selects the element of the instance.
+func namingElement[T any](
+	readByLocal func(
+		aDecoder *xml.Decoder,
+		aCurrent xml.Token,
+		aLocal string,
+	) (value T, aNext xml.Token, anErr error),
+) func(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+) (value T, next xml.Token, err error) {
+	return func(
+		decoder *xml.Decoder,
+		current xml.Token,
+		local string,
+	) (value T, next xml.Token, err error) {
+		value, next, err = readByLocal(decoder, current, local)
+		if err != nil {
+			if deseriaErr, ok := err.(*DeserializationError); ok {
+				deseriaErr.Path.PrependName(
+					&ourreporting.NameSegment{Name: local},
+				)
+			}
+		}
+		return
+	}
+}
+
+// De-serialize an instance of [ourtypes.IItem] based on the `local` name
+// of its start element.
+//
+// The `current` token is expected to point to the content of that start element, and
+// the resulting `next` token points to its end element.
+func readItemDispatched(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+) (instance ourtypes.IItem,
+	next xml.Token,
+	err error,
+) {
+	switch local {
+	case "someItem":
+		instance, next, err = readSomeItemAsSequence(decoder, current)
+	case "specialItem":
+		instance, next, err = readSpecialItemAsSequence(decoder, current)
+	default:
+		err = unexpectedDiscriminator(local, "IItem")
+	}
+	return
+}
+
+// De-serialize the instance of [ourtypes.ISomeItem]
+// as a sequence of XML elements, each representing a property
+// of [ourtypes.ISomeItem].
+//
+// The reading stops as soon as we encounter a non-start element, and we return
+// that token as the `next` token.
+func readSomeItemAsSequence(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (instance ourtypes.ISomeItem,
+	next xml.Token,
+	err error,
+) {
+	var theName string
+	var theNickname *string
+
+	foundName := false
+	foundNickname := false
+
+	for {
+		var local string
+		var ok bool
+		local, current, ok, err = nextProperty(decoder, current, "ISomeItem")
+		if err != nil {
+			return
+		}
+		if !ok {
+			break
+		}
+
+		var valueErr error
+		switch local {
+		case "name":
+			if foundName {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theName, current, valueErr = xmlcommon.ReadText(
+				decoder, current,
+			)
+			foundName = true
+		case "nickname":
+			if foundNickname {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theNickname, current, valueErr = readOptional(
+				xmlcommon.ReadText(decoder, current),
+			)
+			foundNickname = true
+		default:
+			valueErr = xmlcommon.NewDeserializationError(
+				"Unexpected property",
+			)
+		}
+
+		current, err = concludeProperty(decoder, current, local, valueErr)
+		if err != nil {
+			return
+		}
+	}
+
+	next = current
+
+	if !foundName {
+		err = missingProperty("name")
+		return
+	}
+
+	instance = ourtypes.NewSomeItem(
+		theName,
+	)
+	instance.SetNickname(theNickname)
+	return
+}
+
+// De-serialize an instance of [ourtypes.ISomeItem] based on the `local` name
+// of its start element.
+//
+// The `current` token is expected to point to the content of that start element, and
+// the resulting `next` token points to its end element.
+func readSomeItemDispatched(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+) (instance ourtypes.ISomeItem,
+	next xml.Token,
+	err error,
+) {
+	switch local {
+	case "specialItem":
+		instance, next, err = readSpecialItemAsSequence(decoder, current)
+	case "someItem":
+		instance, next, err = readSomeItemAsSequence(decoder, current)
+	default:
+		err = unexpectedDiscriminator(local, "ISomeItem")
+	}
+	return
+}
+
+// De-serialize the instance of [ourtypes.ISpecialItem]
+// as a sequence of XML elements, each representing a property
+// of [ourtypes.ISpecialItem].
+//
+// The reading stops as soon as we encounter a non-start element, and we return
+// that token as the `next` token.
+func readSpecialItemAsSequence(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (instance ourtypes.ISpecialItem,
+	next xml.Token,
+	err error,
+) {
+	var theName string
+	var theNickname *string
+	var theLevel int64
+
+	foundName := false
+	foundNickname := false
+	foundLevel := false
+
+	for {
+		var local string
+		var ok bool
+		local, current, ok, err = nextProperty(decoder, current, "ISpecialItem")
+		if err != nil {
+			return
+		}
+		if !ok {
+			break
+		}
+
+		var valueErr error
+		switch local {
+		case "name":
+			if foundName {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theName, current, valueErr = xmlcommon.ReadText(
+				decoder, current,
+			)
+			foundName = true
+		case "nickname":
+			if foundNickname {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theNickname, current, valueErr = readOptional(
+				xmlcommon.ReadText(decoder, current),
+			)
+			foundNickname = true
+		case "level":
+			if foundLevel {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theLevel, current, valueErr = xmlcommon.ReadTextAs_long(
+				decoder, current,
+			)
+			foundLevel = true
+		default:
+			valueErr = xmlcommon.NewDeserializationError(
+				"Unexpected property",
+			)
+		}
+
+		current, err = concludeProperty(decoder, current, local, valueErr)
+		if err != nil {
+			return
+		}
+	}
+
+	next = current
+
+	if !foundName {
+		err = missingProperty("name")
+		return
+	}
+
+	if !foundLevel {
+		err = missingProperty("level")
+		return
+	}
+
+	instance = ourtypes.NewSpecialItem(
+		theName,
+		theLevel,
+	)
+	instance.SetNickname(theNickname)
+	return
+}
+
+// De-serialize an instance of [ourtypes.ISpecialItem] based on the `local` name
+// of its start element.
+//
+// The `current` token is expected to point to the content of that start element, and
+// the resulting `next` token points to its end element.
+func readSpecialItemDispatched(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+) (instance ourtypes.ISpecialItem,
+	next xml.Token,
+	err error,
+) {
+	switch local {
+	case "specialItem":
+		instance, next, err = readSpecialItemAsSequence(decoder, current)
+	default:
+		err = unexpectedStartElement(local, "specialItem")
+	}
+	return
+}
+
+// De-serialize the instance of [ourtypes.IContainer]
+// as a sequence of XML elements, each representing a property
+// of [ourtypes.IContainer].
+//
+// The reading stops as soon as we encounter a non-start element, and we return
+// that token as the `next` token.
+func readContainerAsSequence(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (instance ourtypes.IContainer,
+	next xml.Token,
+	err error,
+) {
+	var theItems []ourtypes.IItem
+	var theSomeItems []ourtypes.ISomeItem
+	var theSpecialItems []ourtypes.ISpecialItem
+
+	foundItems := false
+	foundSomeItems := false
+	foundSpecialItems := false
+
+	for {
+		var local string
+		var ok bool
+		local, current, ok, err = nextProperty(decoder, current, "IContainer")
+		if err != nil {
+			return
+		}
+		if !ok {
+			break
+		}
+
+		var valueErr error
+		switch local {
+		case "items":
+			if foundItems {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theItems, current, valueErr = readListOf(
+				decoder, current, readItemDispatched,
+			)
+			foundItems = true
+		case "someItems":
+			if foundSomeItems {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theSomeItems, current, valueErr = readListOf(
+				decoder, current, readSomeItemDispatched,
+			)
+			foundSomeItems = true
+		case "specialItems":
+			if foundSpecialItems {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theSpecialItems, current, valueErr = readListOf(
+				decoder, current, readSpecialItemDispatched,
+			)
+			foundSpecialItems = true
+		default:
+			valueErr = xmlcommon.NewDeserializationError(
+				"Unexpected property",
+			)
+		}
+
+		current, err = concludeProperty(decoder, current, local, valueErr)
+		if err != nil {
+			return
+		}
+	}
+
+	next = current
+
+	if !foundItems {
+		err = missingProperty("items")
+		return
+	}
+
+	if !foundSomeItems {
+		err = missingProperty("someItems")
+		return
+	}
+
+	instance = ourtypes.NewContainer(
+		theItems,
+		theSomeItems,
+	)
+	instance.SetSpecialItems(theSpecialItems)
+	return
+}
+
+// De-serialize the instance of [ourtypes.IWrapper]
+// as a sequence of XML elements, each representing a property
+// of [ourtypes.IWrapper].
+//
+// The reading stops as soon as we encounter a non-start element, and we return
+// that token as the `next` token.
+func readWrapperAsSequence(
+	decoder *xml.Decoder,
+	current xml.Token,
+) (instance ourtypes.IWrapper,
+	next xml.Token,
+	err error,
+) {
+	var theContainer ourtypes.IContainer
+
+	foundContainer := false
+
+	for {
+		var local string
+		var ok bool
+		local, current, ok, err = nextProperty(decoder, current, "IWrapper")
+		if err != nil {
+			return
+		}
+		if !ok {
+			break
+		}
+
+		var valueErr error
+		switch local {
+		case "container":
+			if foundContainer {
+				valueErr = duplicatePropertyError(local)
+				break
+			}
+			theContainer, current, valueErr = readContainerAsSequence(
+				decoder, current,
+			)
+			foundContainer = true
+		default:
+			valueErr = xmlcommon.NewDeserializationError(
+				"Unexpected property",
+			)
+		}
+
+		current, err = concludeProperty(decoder, current, local, valueErr)
+		if err != nil {
+			return
+		}
+	}
+
+	next = current
+
+	if !foundContainer {
+		err = missingProperty("container")
+		return
+	}
+
+	instance = ourtypes.NewWrapper(
+		theContainer,
+	)
+	return
+}
+
+// De-serialize an instance of [ourtypes.IClass] based on the `local` name
+// of its start element.
+//
+// The `current` token is expected to point to the content of that start element, and
+// the resulting `next` token points to its end element.
+func readClassDispatched(
+	decoder *xml.Decoder,
+	current xml.Token,
+	local string,
+) (instance ourtypes.IClass,
+	next xml.Token,
+	err error,
+) {
+	switch local {
+	case "someItem":
+		instance, next, err = readSomeItemAsSequence(decoder, current)
+	case "specialItem":
+		instance, next, err = readSpecialItemAsSequence(decoder, current)
+	case "container":
+		instance, next, err = readContainerAsSequence(decoder, current)
+	case "wrapper":
+		instance, next, err = readWrapperAsSequence(decoder, current)
+	default:
+		err = xmlcommon.NewDeserializationError(
+			fmt.Sprintf(
+				"Unexpected XML element name %s as class discriminator",
+				local,
+			),
+		)
+	}
+	return
+}
+
+// Unmarshal an instance of [ourtypes.IClass] serialized as an XML element.
+//
+// The XML element must live in the [Namespace] space.
+func Unmarshal(
+	decoder *xml.Decoder,
+) (instance ourtypes.IClass, err error) {
+	var current xml.Token
+	current, err = xmlcommon.ReadNext(decoder, nil)
+	if err != nil {
+		return
+	}
+
+	// NOTE (mristin):
+	// We skip the prolog before the root element, *i.e.*, the XML declaration,
+	// the processing instructions, the comments and the whitespace.
+	for {
+		current, err = xmlcommon.SkipEmptyTextWhitespaceAndComments(decoder, current)
+		if err != nil {
+			return
+		}
+
+		if _, ok := current.(xml.ProcInst); !ok {
+			break
+		}
+
+		current, err = xmlcommon.ReadNext(decoder, current)
+		if err != nil {
+			return
+		}
+	}
+
+	instance, _, err = xmlcommon.ReadElementDispatched(
+		decoder, current, namingElement(readClassDispatched),
+	)
+	return
+}
+
+// endregion
+
+// region Serialization
+
+// Represent an error during the serialization.
+//
+// Implements `error`.
+type SerializationError = xmlcommon.SerializationError
+
+// Write the optional `that` as an XML element with the `local` name, or write
+// nothing at all if it is not set.
+//
+// Do not flush.
+//
+// A scalar and a tuple are not nilable in Golang, so an optional one is represented
+// as a pointer. The pointer is dereferenced here, so that `writeContent` sees only
+// the value. See also [writeOptionalInstance] and [writeOptionalSlice], which differ
+// from this function only in how the presence is decided.
+func writeOptionalPointer[T any](
+	encoder *xml.Encoder,
+	local string,
+	that *T,
+	writeContent func(anEncoder *xml.Encoder, aValue T) (anErr error),
+) (err error) {
+	if that == nil {
+		return
+	}
+
+	return xmlcommon.WriteElement(encoder, local, *that, writeContent)
+}
+
+// Write the optional instance `that` as an XML element with the `local` name, or
+// write nothing at all if it is not set.
+//
+// Do not flush.
+//
+// An instance is represented as an interface and a named union as a pointer to
+// a struct, both of which are nil on their own, so -- unlike in [writeOptionalPointer] --
+// there is no pointer to dereference.
+//
+// Golang does not allow a value of a type parameter to be compared against `nil`,
+// and `any(that) == nil` would not do either: a nil *pointer* converted to `any` is
+// a non-nil `any` which carries the type of that pointer. Comparing against
+// the zero value of `T` covers both, as it compares nil against nil for
+// an interface, and a nil pointer against a nil pointer of the same type for
+// a named union.
+func writeOptionalInstance[T any](
+	encoder *xml.Encoder,
+	local string,
+	that T,
+	writeContent func(anEncoder *xml.Encoder, aValue T) (anErr error),
+) (err error) {
+	var unset T
+	if any(that) == any(unset) {
+		return
+	}
+
+	return xmlcommon.WriteElement(encoder, local, that, writeContent)
+}
+
+// Write the optional `that` as an XML element with the `local` name, or write
+// nothing at all if it is not set.
+//
+// Do not flush.
+//
+// A list and the bytes are represented as a slice, which is nil on its own, but --
+// unlike an instance in [writeOptionalInstance] -- can not be compared against
+// the zero value, as a slice is not comparable at all. Mind that a nil slice and
+// an empty slice differ here: only the former is considered absent, while
+// the latter is written as an empty XML element.
+func writeOptionalSlice[T any](
+	encoder *xml.Encoder,
+	local string,
+	that []T,
+	writeContent func(anEncoder *xml.Encoder, aValue []T) (anErr error),
+) (err error) {
+	if that == nil {
+		return
+	}
+
+	return xmlcommon.WriteElement(encoder, local, that, writeContent)
+}
+
+// Write the items of the `list`, each as an XML element of its own.
+//
+// Do not flush.
+//
+// The element *around* the list is framed by whoever writes the list, see
+// the generated `writeListOf*` functions. Every item frames its own element
+// through `writeItem`: an instance is written as an element named after its model
+// type, while a scalar is wrapped in the element `v`. A list of instances and
+// a list of scalars therefore share this one function.
+func writeList[T any](
+	encoder *xml.Encoder,
+	list []T,
+	writeItem func(anEncoder *xml.Encoder, aValue T) (anErr error),
+) (err error) {
+	for i, item := range list {
+		err = writeItem(encoder, item)
+		if err != nil {
+			if seriaErr, ok := err.(*SerializationError); ok {
+				seriaErr.Path.PrependIndex(
+					&ourreporting.IndexSegment{Index: i},
+				)
+			}
+			return
+		}
+	}
+
+	return
+}
+
+// Conclude the writing of the property read by `getter` by attributing the error,
+// if any, to that property.
+//
+// Do not flush.
+//
+// `getter` is the getter of the property *as it is spelled in Golang*, `Value()`
+// and not `value`, since it is prepended to the path of a serialization error,
+// which [SerializationError.PathString] renders as a Golang expression through
+// [ourreporting.ToGolangPath]. (Golang has no way to name a member at compile time,
+// so the getter has to be spelled out; mind that the de-serialization reports
+// an XPath instead, and hence prepends the XML name there.)
+//
+// The write itself is given as its *result*, not as a function to be called, so that
+// this one function concludes every property, no matter which of the `write*`
+// functions wrote it, and no matter how many arguments that function took. Golang
+// evaluates the argument, hence performs the write, before this call.
+func finishProperty(
+	getter string,
+	err error,
+) error {
+	if err != nil {
+		if seriaErr, ok := err.(*SerializationError); ok {
+			seriaErr.Path.PrependName(
+				&ourreporting.NameSegment{Name: getter},
+			)
+		}
+		return err
+	}
+
+	return nil
+}
+
+// Write the instance `that` as an XML element named after its model type.
+//
+// Do not flush.
+//
+// This is the content writer of every instance which is not embedded in the element
+// of its property, be it a property, a list item or a tuple item: [Marshal] picks
+// the element name from the runtime model type.
+//
+// Golang function values are invariant in their parameter type, so [Marshal], which
+// takes the wide [ourtypes.IClass], can not be used where a writer of a more
+// specific interface is expected -- this generic function exists solely to narrow
+// the parameter type to `T`. Golang can not infer `T` from the context here, so
+// every call site instantiates it explicitly, *e.g.*,
+// `writeInstance[ourtypes.IReference]`, and passes it on as that instantiated
+// function value, without a closure.
+func writeInstance[T ourtypes.IClass](
+	encoder *xml.Encoder,
+	that T,
+) error {
+	return writeClass(encoder, that, false)
+}
+
+// Write `that` as an XML element with the `local` name representing its model type.
+//
+// Do not flush.
+//
+// If `withNamespace` is set, the `xmlns` attribute is set in the outer XML element.
+//
+// Unlike [xmlcommon.WriteElement], which frames a *property*, this function frames
+// an instance in the element which discriminates its model type, and is therefore
+// the one place where the XML namespace can be set.
+func writeClassElement[T any](
+	encoder *xml.Encoder,
+	local string,
+	withNamespace bool,
+	that T,
+	writeTAsSequence func(anEncoder *xml.Encoder, aValue T) (anErr error),
+) (err error) {
+	err = xmlcommon.WriteStartElement(encoder, local, withNamespace)
+	if err != nil {
+		return
+	}
+
+	err = writeTAsSequence(encoder, that)
+	if err != nil {
+		return
+	}
+
+	err = xmlcommon.WriteEndElement(encoder, local, withNamespace)
+	return
+}
+
+// Write the items of the `list` as a sequence of XML elements.
+//
+// Do not flush.
+func writeListOf_IItem(
+	encoder *xml.Encoder,
+	list []ourtypes.IItem,
+) error {
+	return writeList(
+		encoder, list, writeInstance[ourtypes.IItem],
+	)
+}
+
+// Write the items of the `list` as a sequence of XML elements.
+//
+// Do not flush.
+func writeListOf_ISomeItem(
+	encoder *xml.Encoder,
+	list []ourtypes.ISomeItem,
+) error {
+	return writeList(
+		encoder, list, writeInstance[ourtypes.ISomeItem],
+	)
+}
+
+// Write the items of the `list` as a sequence of XML elements.
+//
+// Do not flush.
+func writeListOf_ISpecialItem(
+	encoder *xml.Encoder,
+	list []ourtypes.ISpecialItem,
+) error {
+	return writeList(
+		encoder, list, writeInstance[ourtypes.ISpecialItem],
+	)
+}
+
+// Serialize the instance
+// of [ourtypes.ISomeItem]
+// as a sequence of properties, each represented as an XML element.
+//
+// The XML namespace is expected to be set in the one of the parent elements
+// enclosing the sequence.
+//
+// Do not flush.
+func writeSomeItemAsSequence(
+	encoder *xml.Encoder,
+	that ourtypes.ISomeItem,
+) (err error) {
+	err = finishProperty(
+		"Name()",
+		xmlcommon.WriteElement(
+			encoder, "name", that.Name(), xmlcommon.WriteAsText_string,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	err = finishProperty(
+		"Nickname()",
+		writeOptionalPointer(
+			encoder, "nickname", that.Nickname(), xmlcommon.WriteAsText_string,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// Serialize the instance
+// of [ourtypes.ISpecialItem]
+// as a sequence of properties, each represented as an XML element.
+//
+// The XML namespace is expected to be set in the one of the parent elements
+// enclosing the sequence.
+//
+// Do not flush.
+func writeSpecialItemAsSequence(
+	encoder *xml.Encoder,
+	that ourtypes.ISpecialItem,
+) (err error) {
+	err = finishProperty(
+		"Name()",
+		xmlcommon.WriteElement(
+			encoder, "name", that.Name(), xmlcommon.WriteAsText_string,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	err = finishProperty(
+		"Nickname()",
+		writeOptionalPointer(
+			encoder, "nickname", that.Nickname(), xmlcommon.WriteAsText_string,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	err = finishProperty(
+		"Level()",
+		xmlcommon.WriteElement(
+			encoder, "level", that.Level(), xmlcommon.WriteAsText_long,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// Serialize the instance
+// of [ourtypes.IContainer]
+// as a sequence of properties, each represented as an XML element.
+//
+// The XML namespace is expected to be set in the one of the parent elements
+// enclosing the sequence.
+//
+// Do not flush.
+func writeContainerAsSequence(
+	encoder *xml.Encoder,
+	that ourtypes.IContainer,
+) (err error) {
+	err = finishProperty(
+		"Items()",
+		xmlcommon.WriteElement(
+			encoder, "items", that.Items(), writeListOf_IItem,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	err = finishProperty(
+		"SomeItems()",
+		xmlcommon.WriteElement(
+			encoder, "someItems", that.SomeItems(), writeListOf_ISomeItem,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	err = finishProperty(
+		"SpecialItems()",
+		writeOptionalSlice(
+			encoder, "specialItems", that.SpecialItems(), writeListOf_ISpecialItem,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// Serialize the instance
+// of [ourtypes.IWrapper]
+// as a sequence of properties, each represented as an XML element.
+//
+// The XML namespace is expected to be set in the one of the parent elements
+// enclosing the sequence.
+//
+// Do not flush.
+func writeWrapperAsSequence(
+	encoder *xml.Encoder,
+	that ourtypes.IWrapper,
+) (err error) {
+	err = finishProperty(
+		"Container()",
+		xmlcommon.WriteElement(
+			encoder, "container", that.Container(), writeContainerAsSequence,
+		),
+	)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// Serialize `that` instance as an XML element named after its model type.
+//
+// Do not flush.
+//
+// If `withNamespace` is set, the `xmlns` attribute is set in the XML element
+// to [Namespace].
+func writeClass(
+	encoder *xml.Encoder,
+	that ourtypes.IClass,
+	withNamespace bool,
+) (err error) {
+	switch that.ModelType() {
+	case ourtypes.ModelTypeSomeItem:
+		err = writeClassElement(
+			encoder,
+			"someItem",
+			withNamespace,
+			that.(ourtypes.ISomeItem),
+			writeSomeItemAsSequence,
+		)
+	case ourtypes.ModelTypeSpecialItem:
+		err = writeClassElement(
+			encoder,
+			"specialItem",
+			withNamespace,
+			that.(ourtypes.ISpecialItem),
+			writeSpecialItemAsSequence,
+		)
+	case ourtypes.ModelTypeContainer:
+		err = writeClassElement(
+			encoder,
+			"container",
+			withNamespace,
+			that.(ourtypes.IContainer),
+			writeContainerAsSequence,
+		)
+	case ourtypes.ModelTypeWrapper:
+		err = writeClassElement(
+			encoder,
+			"wrapper",
+			withNamespace,
+			that.(ourtypes.IWrapper),
+			writeWrapperAsSequence,
+		)
+	default:
+		err = xmlcommon.NewSerializationError(
+			fmt.Sprintf(
+				"Unexpected model type: %v",
+				that.ModelType(),
+			),
+		)
+	}
+	return
+}
+
+// Serialize `that` instance as an XML element, and flush the encoder.
+//
+// If `withNamespace` is set, the `xmlns` attribute is set in the XML element
+// to [Namespace].
+func Marshal(
+	encoder *xml.Encoder,
+	that ourtypes.IClass,
+	withNamespace bool,
+) (err error) {
+	err = writeClass(encoder, that, withNamespace)
+	if err != nil {
+		return
+	}
+
+	return encoder.Flush()
+}
+
+// endregion
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/golang/expected/variance_of_containers/input/snippets/repo_url.txt b/dev/test_data/main/golang/expected/variance_of_containers/input/snippets/repo_url.txt
new file mode 100644
index 000000000..44f004031
--- /dev/null
+++ b/dev/test_data/main/golang/expected/variance_of_containers/input/snippets/repo_url.txt
@@ -0,0 +1 @@
+github.com/dummy-works/dummy
\ No newline at end of file
diff --git a/dev/test_data/main/golang/expected/visibility/expected_output/common/common.go b/dev/test_data/main/golang/expected/visibility/expected_output/common/common.go
index 0f9a80b11..df990e9ed 100644
--- a/dev/test_data/main/golang/expected/visibility/expected_output/common/common.go
+++ b/dev/test_data/main/golang/expected/visibility/expected_output/common/common.go
@@ -39,6 +39,22 @@ func SliceContains[T any](s []T, v T) bool {
 	return false
 }
 
+// Check if the slice contains the given instance of a class.
+//
+// In contrast to [SliceContains], the instance can be of a different type than
+// the items of the slice. This is necessary for the items of the generic sequences,
+// which are of a type parameter, and for the instances of the descendants of
+// the class of the items. We compare the instances as ``any``'s, *i.e.*, by their
+// references.
+func SliceContainsInstance[T any](s []T, v any) bool {
+	for _, item := range s {
+		if any(item) == v {
+			return true
+		}
+	}
+	return false
+}
+
 // Check if any of the elements satisfy the condition.
 func Some[V any](condition func(V) bool, l []V) bool {
 	ok := false
diff --git a/dev/test_data/main/java/expected/annotated_assignments/expected_output/src/main/java/dummy/verification/Verification.java b/dev/test_data/main/java/expected/annotated_assignments/expected_output/src/main/java/dummy/verification/Verification.java
index 55c6b8a05..ca62df26a 100644
--- a/dev/test_data/main/java/expected/annotated_assignments/expected_output/src/main/java/dummy/verification/Verification.java
+++ b/dev/test_data/main/java/expected/annotated_assignments/expected_output/src/main/java/dummy/verification/Verification.java
@@ -33,9 +33,11 @@
 public class Verification {
   /**
    * Check an optional class declared with {@code None} and assigned in a loop.
+   *
+   * <p>The argument {@code parents} is declared with the wildcard {@code List<? extends IParent>} instead of the invariant {@code List<IParent>} so that the lists of the descendants of {@link IParent} can be passed without a copy.
    */
   public static Boolean firstChildAIsSmall(
-    List<IParent> parents) {
+    List<? extends IParent> parents) {
     Optional<IChildA> found = Optional.empty();
     for (var parent : parents) {
         if (parent instanceof IChildA) {
@@ -80,10 +82,12 @@ public static Boolean textIsAllowedUnlessLong(
 
   /**
    * Check a non-optional variable declared wider than its value.
+   *
+   * <p>The argument {@code parents} is declared with the wildcard {@code List<? extends IParent>} instead of the invariant {@code List<IParent>} so that the lists of the descendants of {@link IParent} can be passed without a copy.
    */
   public static Boolean lastChildBIsNotZero(
     IParent parent,
-    List<IParent> parents) {
+    List<? extends IParent> parents) {
     IParent last = parent;
     for (var other : parents) {
         last = other;
@@ -316,9 +320,9 @@ public static Boolean finalLocalsAreConsistent(
     Optional<String> optionalText,
     IParent parent) {
     final long limit = 1000;
-    final String label = text;
-    final Optional<String> maybeText = optionalText;
-    final List<String> allTexts = texts;
+    final var label = text;
+    final var maybeText = optionalText;
+    final var allTexts = texts;
     Set<String> seen = new HashSet<String>();
     seen.add(text);
     final Set<String> reservedSeen = (
@@ -326,7 +330,7 @@ public static Boolean finalLocalsAreConsistent(
     final Tuple2<String, Long> pair = new Tuple2<>(
       text,
       number);
-    final IParent base = parent;
+    final var base = parent;
     if (
         reservedSeen.size() > 0
         || StringHelpers.len(label) > limit
diff --git a/dev/test_data/main/java/expected/if_statements/expected_output/src/main/java/dummy/verification/Verification.java b/dev/test_data/main/java/expected/if_statements/expected_output/src/main/java/dummy/verification/Verification.java
index c5eaea096..6c63c6044 100644
--- a/dev/test_data/main/java/expected/if_statements/expected_output/src/main/java/dummy/verification/Verification.java
+++ b/dev/test_data/main/java/expected/if_statements/expected_output/src/main/java/dummy/verification/Verification.java
@@ -237,9 +237,11 @@ public static Boolean narrowingAfterTheOnlyCompletingBranch(
 
   /**
    * Check the narrowing after the {@code continue} and the early return in a loop.
+   *
+   * <p>The argument {@code parents} is declared with the wildcard {@code List<? extends IParent>} instead of the invariant {@code List<IParent>} so that the lists of the descendants of {@link IParent} can be passed without a copy.
    */
   public static Boolean childAsHaveTexts(
-    List<IParent> parents) {
+    List<? extends IParent> parents) {
     for (var parent : parents) {
         if (!(parent instanceof IChildA)) {
             continue;
@@ -256,9 +258,11 @@ public static Boolean childAsHaveTexts(
 
   /**
    * Check the narrowing after the {@code continue} in a loop with a {@code break}.
+   *
+   * <p>The argument {@code parents} is declared with the wildcard {@code List<? extends IParent>} instead of the invariant {@code List<IParent>} so that the lists of the descendants of {@link IParent} can be passed without a copy.
    */
   public static Boolean textsBeforeContainerAreShort(
-    List<IParent> parents) {
+    List<? extends IParent> parents) {
     long total = 0;
     for (var parent : parents) {
         if (parent instanceof IContainer) {
@@ -287,10 +291,12 @@ public static Boolean textOrDefaultIsShort(
 
   /**
    * Check the narrowing of a variable to a class by the assigned value.
+   *
+   * <p>The argument {@code parents} is declared with the wildcard {@code List<? extends IParent>} instead of the invariant {@code List<IParent>} so that the lists of the descendants of {@link IParent} can be passed without a copy.
    */
   public static Boolean lastChildAIsSmall(
     IParent parent,
-    List<IParent> parents) {
+    List<? extends IParent> parents) {
     var last = parent;
     for (var other : parents) {
         if (other instanceof IChildA) {
diff --git a/dev/test_data/main/java/expected/list_of_classes/expected_output/src/main/java/dummy/verification/Verification.java b/dev/test_data/main/java/expected/list_of_classes/expected_output/src/main/java/dummy/verification/Verification.java
index 289665344..a7197d9a1 100644
--- a/dev/test_data/main/java/expected/list_of_classes/expected_output/src/main/java/dummy/verification/Verification.java
+++ b/dev/test_data/main/java/expected/list_of_classes/expected_output/src/main/java/dummy/verification/Verification.java
@@ -61,9 +61,11 @@ public static List<ISimple> simplesWith(
    *
    * <p>The appended items are narrowed down to {@link dummy.types.impl.SomeItem}, while the list
    * holds {@link dummy.types.model.IAbstractItem}'s.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IAbstractItem>} instead of the invariant {@code List<IAbstractItem>} so that the lists of the descendants of {@link IAbstractItem} can be passed without a copy.
    */
   public static List<IAbstractItem> someItemsOf(
-    List<IAbstractItem> items) {
+    List<? extends IAbstractItem> items) {
     List<IAbstractItem> result = new java.util.ArrayList<IAbstractItem>();
     for (var item : items) {
         if (item instanceof ISomeItem) {
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/StringHelpers.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/StringHelpers.java
new file mode 100644
index 000000000..6fb64774d
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/StringHelpers.java
@@ -0,0 +1,142 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Provide string operations which follow the Python implementation, since
+ * Python is the language of the meta-model specifications.
+ *
+ * <p>The lengths and the positions count the characters (code points), and not
+ * the UTF-16 code units of the Java strings. Hence, a character beyond the Basic
+ * Multilingual Plane counts as one, though it takes two UTF-16 code units
+ * (a surrogate pair).
+ */
+public final class StringHelpers {
+  private StringHelpers() {
+    // Prevent instantiation
+  }
+
+  /**
+   * Resolve {@code position} in a string of {@code length} as Python does
+   * in slicing.
+   *
+   * <p>A negative position counts from the end, and the positions out of range
+   * are clamped to the string.
+   *
+   * @param position to be resolved
+   * @param length of the string
+   * @return the resolved position within {@code [0, length]}
+   */
+  private static int resolvePosition(long position, int length) {
+    if (position < 0) {
+      return (int) Math.max(position + length, 0);
+    }
+
+    return (int) Math.min(position, length);
+  }
+
+  /**
+   * Count the characters (code points) of {@code text}.
+   *
+   * <p>We follow the Python implementation of {@code len}, since Python is
+   * the language of the meta-model specifications. Hence, a character beyond
+   * the Basic Multilingual Plane counts as one, unlike in {@code text.length()}.
+   *
+   * @param text to be measured
+   * @return the number of characters
+   */
+  public static int len(String text) {
+    return text.codePointCount(0, text.length());
+  }
+
+  /**
+   * Slice {@code text} from {@code start} up to {@code end}, exclusive.
+   *
+   * <p>We follow the Python implementation of slicing, since Python is
+   * the language of the meta-model specifications. Hence, the positions count
+   * the characters (code points), a negative position counts from the end,
+   * the positions out of range are clamped to the string, and the slice is empty
+   * if {@code start} is not before {@code end}.
+   *
+   * @param text to be sliced
+   * @param start of the slice, inclusive
+   * @param end of the slice, exclusive
+   * @return the slice
+   */
+  public static String slice(String text, long start, long end) {
+    final int length = len(text);
+    final int theStart = resolvePosition(start, length);
+    final int theEnd = resolvePosition(end, length);
+
+    if (theStart >= theEnd) {
+      return "";
+    }
+
+    final int startOffset = text.offsetByCodePoints(0, theStart);
+    final int endOffset = text.offsetByCodePoints(startOffset, theEnd - theStart);
+    return text.substring(startOffset, endOffset);
+  }
+
+  /**
+   * Slice {@code text} from {@code start} up to its end.
+   *
+   * <p>See {@link #slice(String, long, long)} for the semantics.
+   *
+   * @param text to be sliced
+   * @param start of the slice, inclusive
+   * @return the slice
+   */
+  public static String slice(String text, long start) {
+    return slice(text, start, Long.MAX_VALUE);
+  }
+
+  /**
+   * Find the first {@code sub} in {@code text} from {@code start} on.
+   *
+   * <p>We follow the Python implementation of {@code str.find}, since Python
+   * is the language of the meta-model specifications. Hence, the positions count
+   * the characters (code points), a negative {@code start} counts from the end,
+   * and a {@code start} beyond the end of {@code text} gives -1.
+   *
+   * @param text to be searched in
+   * @param sub to be searched for
+   * @param start of the search
+   * @return the position of {@code sub} in {@code text}, or -1 if not found
+   */
+  public static long find(String text, String sub, long start) {
+    final int length = len(text);
+    final long theStart = start < 0 ? Math.max(start + length, 0) : start;
+    if (theStart > length) {
+      return -1;
+    }
+
+    final int startOffset = text.offsetByCodePoints(0, (int) theStart);
+    final int offset = text.indexOf(sub, startOffset);
+    if (offset == -1) {
+      return -1;
+    }
+
+    return theStart + text.codePointCount(startOffset, offset);
+  }
+
+  /**
+   * Find the first {@code sub} in {@code text}.
+   *
+   * <p>See {@link #find(String, String, long)} for the semantics.
+   *
+   * @param text to be searched in
+   * @param sub to be searched for
+   * @return the position of {@code sub} in {@code text}, or -1 if not found
+   */
+  public static long find(String text, String sub) {
+    return find(text, sub, 0);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple1.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple1.java
new file mode 100644
index 000000000..baa4b7a97
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple1.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 1 item(s).
+ */
+public record Tuple1<T1>(T1 item1) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 1;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple2.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple2.java
new file mode 100644
index 000000000..ee3123a29
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple2.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 2 item(s).
+ */
+public record Tuple2<T1, T2>(T1 item1, T2 item2) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 2;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple3.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple3.java
new file mode 100644
index 000000000..fac1f9e6d
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple3.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 3 item(s).
+ */
+public record Tuple3<T1, T2, T3>(T1 item1, T2 item2, T3 item3) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 3;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple4.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple4.java
new file mode 100644
index 000000000..47e2fd515
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple4.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 4 item(s).
+ */
+public record Tuple4<T1, T2, T3, T4>(T1 item1, T2 item2, T3 item3, T4 item4) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 4;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple5.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple5.java
new file mode 100644
index 000000000..94bf6d723
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple5.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 5 item(s).
+ */
+public record Tuple5<T1, T2, T3, T4, T5>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 5;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple6.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple6.java
new file mode 100644
index 000000000..663ee4bcc
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple6.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 6 item(s).
+ */
+public record Tuple6<T1, T2, T3, T4, T5, T6>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 6;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple7.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple7.java
new file mode 100644
index 000000000..8c5cbe846
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple7.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 7 item(s).
+ */
+public record Tuple7<T1, T2, T3, T4, T5, T6, T7>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 7;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple8.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple8.java
new file mode 100644
index 000000000..3ba3c0908
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/common/Tuple8.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.common;
+
+/**
+ * Represent a fixed-size heterogeneous tuple of 8 item(s).
+ */
+public record Tuple8<T1, T2, T3, T4, T5, T6, T7, T8>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7, T8 item8) {
+  /**
+   * Count the items of the tuple.
+   */
+  public int size() {
+    return 8;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/constants/Constants.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/constants/Constants.java
new file mode 100644
index 000000000..bf920884e
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/constants/Constants.java
@@ -0,0 +1,37 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.constants;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collector;
+import java.util.stream.Stream;
+
+
+
+// Helper to generate read-only collections with less boilerplate.
+// See: https://stackoverflow.com/a/37406054
+class _ImmutableCollector {
+    public static <T> Collector<T, Set<T>, Set<T>> toImmutableSet() {
+        return Collector.of(HashSet::new, Set::add, (l, r) -> {
+            l.addAll(r);
+            return l;
+        }, Collections::unmodifiableSet);
+    }
+}
+
+/**
+ * Provide constant values of the meta-model.
+ */
+public class Constants {
+
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/copying/Copying.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/copying/Copying.java
new file mode 100644
index 000000000..41b2c4e59
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/copying/Copying.java
@@ -0,0 +1,175 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.copying;
+
+import java.util.List;
+import java.util.ArrayList;
+import dummy.common.*;
+import dummy.types.model.IClass;
+import dummy.visitation.AbstractTransformer;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+
+/**
+ * Allow for making shallow and deep copies of model instances.
+ */
+public class Copying
+{
+    private static final _ShallowCopier shallowCopierInstance = new _ShallowCopier();
+
+    private static final _DeepCopier deepCopierInstance = new _DeepCopier();
+
+    /**
+     * Make a shallow copy of {@code that}.
+     *
+     * <p>All the properties are copied by reference. This includes also the lists.
+     * Hence, a list property is copied by reference, and not, as sometimes might be
+     * expected, as a new list of underlying references.
+     *
+     * @param that to be copied in a shallow manner
+     */
+    @SuppressWarnings("unchecked")
+    public static <T extends IClass> T shallow(T that) {
+        return (T) shallowCopierInstance.transform(that);
+    }
+
+    /**
+     * Make a recursively a deep copy of {@code that}.
+     *
+     * @param that to be deeply copied in a recursive manner
+     */
+    @SuppressWarnings("unchecked")
+    public static <T extends IClass> T deep(T that) {
+        return (T) deepCopierInstance.transform(that);
+    }
+
+    /**
+     * Make a deep copy of {@code that}, copying its items recursively.
+     */
+    private static List<IItem> deepListOf_IItem(
+        List<IItem> that) {
+        List<IItem> result = new ArrayList<>(that.size());
+        for (IItem item : that) {
+            result.add(deep(item));
+        }
+        return result;
+    }
+
+    /**
+     * Make a deep copy of {@code that}, copying its items recursively.
+     */
+    private static List<ISomeItem> deepListOf_ISomeItem(
+        List<ISomeItem> that) {
+        List<ISomeItem> result = new ArrayList<>(that.size());
+        for (ISomeItem item : that) {
+            result.add(deep(item));
+        }
+        return result;
+    }
+
+    /**
+     * Make a deep copy of {@code that}, copying its items recursively.
+     */
+    private static List<ISpecialItem> deepListOf_ISpecialItem(
+        List<ISpecialItem> that) {
+        List<ISpecialItem> result = new ArrayList<>(that.size());
+        for (ISpecialItem item : that) {
+            result.add(deep(item));
+        }
+        return result;
+    }
+
+    /**
+     * Dispatch the making of shallow copies.
+     */
+    private static class _ShallowCopier extends AbstractTransformer<IClass> {
+        @Override
+        public IClass transformSomeItem(
+            ISomeItem that
+        ) {
+            return new SomeItem(that.getName(), that.getNickname().orElse(null));
+        }
+
+        @Override
+        public IClass transformSpecialItem(
+            ISpecialItem that
+        ) {
+            return new SpecialItem(
+                that.getName(),
+                that.getLevel(),
+                that.getNickname().orElse(null));
+        }
+
+        @Override
+        public IClass transformContainer(
+            IContainer that
+        ) {
+            return new Container(
+                that.getItems(),
+                that.getSomeItems(),
+                that.getSpecialItems().orElse(null));
+        }
+
+        @Override
+        public IClass transformWrapper(
+            IWrapper that
+        ) {
+            return new Wrapper(that.getContainer());
+        }
+    }
+
+    /** Dispatch the making of deep copies. */
+    private static class _DeepCopier extends AbstractTransformer<IClass> {
+        @Override
+        public IClass transformSomeItem (
+            ISomeItem that
+        ) {
+            return new SomeItem(
+                that.getName(),
+                that.getNickname().orElse(null)
+            );
+        }
+
+        @Override
+        public IClass transformSpecialItem (
+            ISpecialItem that
+        ) {
+            return new SpecialItem(
+                that.getName(),
+                that.getLevel(),
+                that.getNickname().orElse(null)
+            );
+        }
+
+        @Override
+        public IClass transformContainer (
+            IContainer that
+        ) {
+            return new Container(
+                deepListOf_IItem(that.getItems()),
+                deepListOf_ISomeItem(that.getSomeItems()),
+                that.getSpecialItems().isPresent()
+                    ? deepListOf_ISpecialItem(that.getSpecialItems().get())
+                    : null
+            );
+        }
+
+        @Override
+        public IClass transformWrapper (
+            IWrapper that
+        ) {
+            return new Wrapper(
+                deep(that.getContainer())
+            );
+        }
+    }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhanced.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhanced.java
new file mode 100644
index 000000000..d579663c2
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhanced.java
@@ -0,0 +1,23 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+public abstract class Enhanced<EnhancementT> {
+  protected final EnhancementT enhancement;
+
+  protected Enhanced(EnhancementT enhancement) {
+    this.enhancement = enhancement;
+  }
+
+  EnhancementT getEnhancement() {
+    return enhancement;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedContainer.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedContainer.java
new file mode 100644
index 000000000..25f761ac9
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedContainer.java
@@ -0,0 +1,110 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.lang.Iterable;
+import java.util.Optional;
+import java.util.List;
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+
+public class EnhancedContainer<EnhancementT>
+  extends Enhanced<EnhancementT>
+  implements IContainer {
+  private final IContainer instance;
+
+  public EnhancedContainer(
+    IContainer instance,
+    EnhancementT enhancement
+  ) {
+    super(enhancement);
+    this.instance = instance;
+  }
+
+  @Override
+  public List<IItem> getItems() {
+    return instance.getItems();
+  }
+
+  @Override
+  public void setItems(List<IItem> items) {
+    instance.setItems(items);
+  }
+
+  @Override
+  public List<ISomeItem> getSomeItems() {
+    return instance.getSomeItems();
+  }
+
+  @Override
+  public void setSomeItems(List<ISomeItem> someItems) {
+    instance.setSomeItems(someItems);
+  }
+
+  @Override
+  public Optional<List<ISpecialItem>> getSpecialItems() {
+    return instance.getSpecialItems();
+  }
+
+  @Override
+  public void setSpecialItems(List<ISpecialItem> specialItems) {
+    instance.setSpecialItems(specialItems);
+  }
+
+  public Iterable<ISpecialItem> overSpecialItemsOrEmpty() {
+    return instance.overSpecialItemsOrEmpty();
+  }
+
+  public Long countItems(
+    List<IItem> items
+  )
+  {
+    return instance.countItems(
+      items
+    );
+  }
+
+  public Iterable<IClass> descendOnce() {
+    return instance.descendOnce();
+  }
+
+  public Iterable<IClass> descend() {
+    return instance.descend();
+  }
+
+  public void accept(IVisitor visitor) {
+    visitor.visitContainer(instance);
+  }
+
+  public <ContextT> void accept(
+    IVisitorWithContext<ContextT> visitor,
+    ContextT context
+  ) {
+    visitor.visitContainer(instance, context);
+  }
+
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformContainer(instance);
+  }
+
+  public <ContextT, T> T transform(
+    ITransformerWithContext<ContextT, T> transformer,
+    ContextT context
+  ) {
+    return transformer.transformContainer(instance, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSomeItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSomeItem.java
new file mode 100644
index 000000000..171f027b1
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSomeItem.java
@@ -0,0 +1,87 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.lang.Iterable;
+import java.util.Optional;
+import java.util.List;
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+
+public class EnhancedSomeItem<EnhancementT>
+  extends Enhanced<EnhancementT>
+  implements ISomeItem {
+  private final ISomeItem instance;
+
+  public EnhancedSomeItem(
+    ISomeItem instance,
+    EnhancementT enhancement
+  ) {
+    super(enhancement);
+    this.instance = instance;
+  }
+
+  @Override
+  public String getName() {
+    return instance.getName();
+  }
+
+  @Override
+  public void setName(String name) {
+    instance.setName(name);
+  }
+
+  @Override
+  public Optional<String> getNickname() {
+    return instance.getNickname();
+  }
+
+  @Override
+  public void setNickname(String nickname) {
+    instance.setNickname(nickname);
+  }
+
+  public Iterable<IClass> descendOnce() {
+    return instance.descendOnce();
+  }
+
+  public Iterable<IClass> descend() {
+    return instance.descend();
+  }
+
+  public void accept(IVisitor visitor) {
+    visitor.visitSomeItem(instance);
+  }
+
+  public <ContextT> void accept(
+    IVisitorWithContext<ContextT> visitor,
+    ContextT context
+  ) {
+    visitor.visitSomeItem(instance, context);
+  }
+
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformSomeItem(instance);
+  }
+
+  public <ContextT, T> T transform(
+    ITransformerWithContext<ContextT, T> transformer,
+    ContextT context
+  ) {
+    return transformer.transformSomeItem(instance, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSpecialItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSpecialItem.java
new file mode 100644
index 000000000..e5a5a3861
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedSpecialItem.java
@@ -0,0 +1,97 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.lang.Iterable;
+import java.util.Optional;
+import java.util.List;
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+
+public class EnhancedSpecialItem<EnhancementT>
+  extends Enhanced<EnhancementT>
+  implements ISpecialItem {
+  private final ISpecialItem instance;
+
+  public EnhancedSpecialItem(
+    ISpecialItem instance,
+    EnhancementT enhancement
+  ) {
+    super(enhancement);
+    this.instance = instance;
+  }
+
+  @Override
+  public String getName() {
+    return instance.getName();
+  }
+
+  @Override
+  public void setName(String name) {
+    instance.setName(name);
+  }
+
+  @Override
+  public Optional<String> getNickname() {
+    return instance.getNickname();
+  }
+
+  @Override
+  public void setNickname(String nickname) {
+    instance.setNickname(nickname);
+  }
+
+  @Override
+  public Long getLevel() {
+    return instance.getLevel();
+  }
+
+  @Override
+  public void setLevel(Long level) {
+    instance.setLevel(level);
+  }
+
+  public Iterable<IClass> descendOnce() {
+    return instance.descendOnce();
+  }
+
+  public Iterable<IClass> descend() {
+    return instance.descend();
+  }
+
+  public void accept(IVisitor visitor) {
+    visitor.visitSpecialItem(instance);
+  }
+
+  public <ContextT> void accept(
+    IVisitorWithContext<ContextT> visitor,
+    ContextT context
+  ) {
+    visitor.visitSpecialItem(instance, context);
+  }
+
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformSpecialItem(instance);
+  }
+
+  public <ContextT, T> T transform(
+    ITransformerWithContext<ContextT, T> transformer,
+    ContextT context
+  ) {
+    return transformer.transformSpecialItem(instance, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedWrapper.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedWrapper.java
new file mode 100644
index 000000000..f1a412dc9
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/EnhancedWrapper.java
@@ -0,0 +1,77 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.lang.Iterable;
+import java.util.Optional;
+import java.util.List;
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+
+public class EnhancedWrapper<EnhancementT>
+  extends Enhanced<EnhancementT>
+  implements IWrapper {
+  private final IWrapper instance;
+
+  public EnhancedWrapper(
+    IWrapper instance,
+    EnhancementT enhancement
+  ) {
+    super(enhancement);
+    this.instance = instance;
+  }
+
+  @Override
+  public IContainer getContainer() {
+    return instance.getContainer();
+  }
+
+  @Override
+  public void setContainer(IContainer container) {
+    instance.setContainer(container);
+  }
+
+  public Iterable<IClass> descendOnce() {
+    return instance.descendOnce();
+  }
+
+  public Iterable<IClass> descend() {
+    return instance.descend();
+  }
+
+  public void accept(IVisitor visitor) {
+    visitor.visitWrapper(instance);
+  }
+
+  public <ContextT> void accept(
+    IVisitorWithContext<ContextT> visitor,
+    ContextT context
+  ) {
+    visitor.visitWrapper(instance, context);
+  }
+
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformWrapper(instance);
+  }
+
+  public <ContextT, T> T transform(
+    ITransformerWithContext<ContextT, T> transformer,
+    ContextT context
+  ) {
+    return transformer.transformWrapper(instance, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhancer.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhancer.java
new file mode 100644
index 000000000..3962224db
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Enhancer.java
@@ -0,0 +1,64 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.util.function.Function;
+import java.util.Optional;
+import dummy.enhancing.Unwrapper;
+import dummy.types.model.*;
+
+/**
+ * Wrap and unwrap the instances of model classes with enhancement.
+ *
+ * @param <EnhancementT> structure of the enhancement
+ */
+public class Enhancer<EnhancementT> extends Unwrapper<EnhancementT> {
+  private final _Wrapper<EnhancementT> wrapper;
+
+  /**
+   * @param enhancementFactory how to enhance the instances.
+   *
+   * <p>If it returns {@code null}, the instance will not be wrapped. However,
+   * the wrapping will continue recursively.
+   */
+  public Enhancer(
+    Function<IClass, Optional<EnhancementT>> enhancementFactory
+  ) {
+    this.wrapper = new _Wrapper<>(enhancementFactory);
+  }
+
+  /**
+   * Wrap the instance with an enhancement.
+   *
+   * <p>Double wraps are not allowed to prevent runtime leakage.
+   *
+   * <p>If you use references to the instance objects, you have to update them
+   * after the wrapping, as the wrapping is recursive.
+   *
+   * @param that model instance to be wrapped
+   * @return {@code that} instance wrapped recursively with enhancements
+   */
+  public IClass wrap(
+    IClass that
+  ) {
+    IClass wrapped;
+    try {
+      wrapped = wrapper.transform(that);
+    } catch (IllegalArgumentException exception) {
+      throw new UnsupportedOperationException(
+        "Expected the wrapped instance to be an instance of IClass, " +
+        "but got: " + that
+      );
+    }
+
+    return wrapped;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Unwrapper.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Unwrapper.java
new file mode 100644
index 000000000..588322dc8
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/Unwrapper.java
@@ -0,0 +1,56 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.util.Optional;
+import dummy.types.model.*;
+
+/**
+ * Unwrap enhancements from the wrapped instances.
+ *
+ * @param <EnhancementT> structure of the expected enhancement
+ */
+public class Unwrapper<EnhancementT> {
+  /**
+   * Unwrap the given model instance.
+   *
+   * @param that model instance to be unwrapped
+   * @return Enhancement, or {@link java.util.Optional#empty()} if {@code that}
+   * has not been wrapped yet.
+   */
+  public Optional<EnhancementT> unwrap(IClass that)
+  {
+    if (that instanceof Enhanced) {
+      @SuppressWarnings("unchecked")
+      Enhanced<EnhancementT> enhanced = (Enhanced<EnhancementT>) that;
+      return Optional.of(enhanced.getEnhancement());
+    } else {
+      return Optional.empty();
+    }
+  }
+
+  /**
+   * Unwrap the given model instance.
+   *
+   * @param that model instance to be unwrapped
+   * @return Enhancement wrapped around {@code that}
+   */
+  public EnhancementT mustUnwrap(IClass that)
+  {
+    Optional<EnhancementT> value = unwrap(that);
+    if (!value.isPresent()) {
+      throw new IllegalArgumentException(
+        "Expected the instance to have been wrapped, but it was not: " + that
+      );
+    }
+    return value.get();
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/_Wrapper.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/_Wrapper.java
new file mode 100644
index 000000000..f3441fe87
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/enhancing/_Wrapper.java
@@ -0,0 +1,162 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.enhancing;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Function;
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.model.*;
+import dummy.visitation.AbstractTransformer;
+
+class _Wrapper<EnhancementT> extends AbstractTransformer<IClass> {
+  private final Function<IClass, Optional<EnhancementT>> enhancementFactory;
+
+  _Wrapper(
+    Function<IClass, Optional<EnhancementT>> enhancementFactory
+  ) {
+    this.enhancementFactory = enhancementFactory;
+  }
+
+  @Override
+  public IClass transformSomeItem(
+    ISomeItem that
+  ) {
+    if (that instanceof Enhanced)
+    {
+      throw new IllegalArgumentException(
+        "The instance has been already enhanced: " + that
+      );
+    }
+
+    Optional<EnhancementT> enhancement = enhancementFactory.apply(that);
+    return !enhancement.isPresent()
+      ? that
+      : new EnhancedSomeItem<>(
+        that,
+        enhancement.get()
+      );
+  }
+
+  @Override
+  public IClass transformSpecialItem(
+    ISpecialItem that
+  ) {
+    if (that instanceof Enhanced)
+    {
+      throw new IllegalArgumentException(
+        "The instance has been already enhanced: " + that
+      );
+    }
+
+    Optional<EnhancementT> enhancement = enhancementFactory.apply(that);
+    return !enhancement.isPresent()
+      ? that
+      : new EnhancedSpecialItem<>(
+        that,
+        enhancement.get()
+      );
+  }
+
+  @Override
+  public IClass transformContainer(
+    IContainer that
+  ) {
+    if (that instanceof Enhanced)
+    {
+      throw new IllegalArgumentException(
+        "The instance has been already enhanced: " + that
+      );
+    }
+
+    that.setItems(wrapListOf_IItem(that.getItems()));
+
+    that.setSomeItems(wrapListOf_ISomeItem(that.getSomeItems()));
+
+    if (that.getSpecialItems().isPresent()) {
+      that.setSpecialItems(
+        wrapListOf_ISpecialItem(that.getSpecialItems().get()));
+    }
+
+    Optional<EnhancementT> enhancement = enhancementFactory.apply(that);
+    return !enhancement.isPresent()
+      ? that
+      : new EnhancedContainer<>(
+        that,
+        enhancement.get()
+      );
+  }
+
+  @Override
+  public IClass transformWrapper(
+    IWrapper that
+  ) {
+    if (that instanceof Enhanced)
+    {
+      throw new IllegalArgumentException(
+        "The instance has been already enhanced: " + that
+      );
+    }
+
+    that.setContainer(wrap(that.getContainer()));
+
+    Optional<EnhancementT> enhancement = enhancementFactory.apply(that);
+    return !enhancement.isPresent()
+      ? that
+      : new EnhancedWrapper<>(
+        that,
+        enhancement.get()
+      );
+  }
+
+  @SuppressWarnings("unchecked")
+  private <T extends IClass> T wrap(T that) {
+    return (T) transform(that);
+  }
+
+  /**
+   * Wrap the instances held by {@code that} recursively in a new container.
+   */
+  private List<IItem> wrapListOf_IItem(
+    List<IItem> that) {
+    List<IItem> result = new ArrayList<>(that.size());
+    for (IItem item : that) {
+      result.add(wrap(item));
+    }
+    return result;
+  }
+
+  /**
+   * Wrap the instances held by {@code that} recursively in a new container.
+   */
+  private List<ISomeItem> wrapListOf_ISomeItem(
+    List<ISomeItem> that) {
+    List<ISomeItem> result = new ArrayList<>(that.size());
+    for (ISomeItem item : that) {
+      result.add(wrap(item));
+    }
+    return result;
+  }
+
+  /**
+   * Wrap the instances held by {@code that} recursively in a new container.
+   */
+  private List<ISpecialItem> wrapListOf_ISpecialItem(
+    List<ISpecialItem> that) {
+    List<ISpecialItem> result = new ArrayList<>(that.size());
+    for (ISpecialItem item : that) {
+      result.add(wrap(item));
+    }
+    return result;
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/ContainerBuilder.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/ContainerBuilder.java
new file mode 100644
index 000000000..8fdad0d8c
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/ContainerBuilder.java
@@ -0,0 +1,43 @@
+package dummy.generation;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+/**
+ * Builder for the Container type.
+ */
+public class ContainerBuilder {
+  private List<IItem> items;
+
+  private List<ISomeItem> someItems;
+
+  private List<ISpecialItem> specialItems;
+
+  public ContainerBuilder(
+    List<IItem> items,
+    List<ISomeItem> someItems) {
+    this.items = Objects.requireNonNull(
+      items,
+      "Argument \"items\" must be non-null.");
+    this.someItems = Objects.requireNonNull(
+      someItems,
+      "Argument \"someItems\" must be non-null.");
+  }
+
+  public ContainerBuilder setSpecialItems(List<ISpecialItem> specialItems) {
+    this.specialItems = specialItems;
+    return this;
+  }
+
+  public Container build() {
+    return new Container(
+      this.items,
+      this.someItems,
+      this.specialItems);
+  }
+}
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SomeItemBuilder.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SomeItemBuilder.java
new file mode 100644
index 000000000..5be6adbd1
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SomeItemBuilder.java
@@ -0,0 +1,35 @@
+package dummy.generation;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+/**
+ * Builder for the SomeItem type.
+ */
+public class SomeItemBuilder {
+  private String name;
+
+  private String nickname;
+
+  public SomeItemBuilder(String name) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+  }
+
+  public SomeItemBuilder setNickname(String nickname) {
+    this.nickname = nickname;
+    return this;
+  }
+
+  public SomeItem build() {
+    return new SomeItem(
+      this.name,
+      this.nickname);
+  }
+}
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SpecialItemBuilder.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SpecialItemBuilder.java
new file mode 100644
index 000000000..6daf214e2
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/generation/SpecialItemBuilder.java
@@ -0,0 +1,43 @@
+package dummy.generation;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+/**
+ * Builder for the SpecialItem type.
+ */
+public class SpecialItemBuilder {
+  private String name;
+
+  private String nickname;
+
+  private Long level;
+
+  public SpecialItemBuilder(
+    String name,
+    Long level) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+    this.level = Objects.requireNonNull(
+      level,
+      "Argument \"level\" must be non-null.");
+  }
+
+  public SpecialItemBuilder setNickname(String nickname) {
+    this.nickname = nickname;
+    return this;
+  }
+
+  public SpecialItem build() {
+    return new SpecialItem(
+      this.name,
+      this.level,
+      this.nickname);
+  }
+}
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/jsonization/Jsonization.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/jsonization/Jsonization.java
new file mode 100644
index 000000000..3607b9e9f
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/jsonization/Jsonization.java
@@ -0,0 +1,1050 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.jsonization;
+
+import dummy.common.*;
+import dummy.reporting.Reporting;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import dummy.stringification.Stringification;
+import dummy.visitation.AbstractTransformer;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.JsonNodeFactory;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Function;
+
+/**
+ * Provide de/serialization of meta-model classes to/from JSON.
+ *
+ * <p>We can not use one-pass deserialization for JSON since the object
+ * properties do not have fixed order, and hence we can not read
+ * {@code modelType} property ahead of the remaining properties.
+ */
+public class Jsonization {
+    /**
+     * Implement the deserialization of meta-model classes from JSON nodes.
+     *
+     * <p>The implementation propagates an {@link Reporting.Error} instead
+     * of relying on exceptions. Under the assumption that incorrect data is much
+     * less frequent than correct data, this makes the deserialization more
+     * efficient.
+     *
+     * However, we do not want to force the client to deal with
+     * the {@link Reporting.Error} class as this is not intuitive. Therefore
+     * we distinguish the implementation, realized in
+     * {@link _DeserializeImplementation}, and the facade given in
+     * {@link Deserialize} class.
+     *
+     * <p>Every value is parsed through a function which takes a single
+     * {@link JsonNode} and gives back a {@link Reporting.Result}, so that a list
+     * and a tuple can be composed out of the parsers of their items. Only they
+     * need such a composition -- every other value already has a function named
+     * after its very type.
+     */
+    private static class _DeserializeImplementation {
+      /** Convert {@code value} to a string.
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<String> tryStringFrom(JsonNode value) {
+        if (!value.isTextual()) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a JsonValue of String, but got " + value.getNodeType());
+          return Reporting.Result.failure(error);
+        }
+        return Reporting.Result.success(value.asText());
+      }
+
+      /** Convert {@code value} to a boolean.
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<Boolean> tryBooleanFrom(JsonNode value) {
+        if (!value.isBoolean()) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a JsonValue of Boolean, but got " + value.getNodeType());
+          return Reporting.Result.failure(error);
+        }
+        return Reporting.Result.success(value.asBoolean());
+      }
+
+      /** Convert {@code value} to a long 64-bit integer.
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<Long> tryLongFrom(JsonNode value) {
+        if (!value.isIntegralNumber()) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a JsonValue of Long, but got " + value.getNodeType());
+          return Reporting.Result.failure(error);
+        }
+        return Reporting.Result.success(value.asLong());
+      }
+
+      /** Convert {@code value} to a double-precision 64-bit float.
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<Double> tryDoubleFrom(JsonNode value) {
+        // NOTE (mristin):
+        // We deliberately ask for a number, and not for a floating-point number.
+        // JSON has a single number type, so ``3`` is every bit as good a double as
+        // ``3.0`` is, and every other SDK reads it as one.
+        if (!value.isNumber()) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a JsonValue of Double, but got " + value.getNodeType());
+          return Reporting.Result.failure(error);
+        }
+
+        // NOTE (mristin):
+        // JSON knows neither an infinity nor a not-a-number, so a conformant parser
+        // can never give us one. Jackson parses them when
+        // JsonReadFeature.ALLOW_NON_NUMERIC_NUMBERS is enabled, and the caller can
+        // construct such a node programmatically in any case, so we check here.
+        final double asDouble = value.asDouble();
+        if (!Double.isFinite(asDouble)) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a finite number, but got " + asDouble);
+          return Reporting.Result.failure(error);
+        }
+
+        return Reporting.Result.success(asDouble);
+      }
+
+      private static Reporting.Result<byte[]> tryBytesFrom(JsonNode value) {
+        if (!value.isTextual()) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected a JsonValue of String, but got " + value.getNodeType());
+          return Reporting.Result.failure(error);
+        }
+        final byte[] decodedData;
+        Base64.Decoder decoder = Base64.getDecoder();
+
+        try {
+          decodedData = decoder.decode(value.textValue());
+        } catch (Exception exception) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected Base-64 encoded bytes, but the conversion failed " +
+              "because: " + exception.getMessage());
+          return Reporting.Result.failure(error);
+        }
+
+        return Reporting.Result.success(decodedData);
+      }
+
+      /**
+       * Mark the error of {@code result} as coming from the property {@code name}.
+       *
+       * <p>A {@code case} of a property loop is matched exactly when the key of
+       * the property equals its literal, so the key already names the property and
+       * no {@code case} has to spell it out a second time.
+       */
+      private static <T> Reporting.Result<T> prependName(
+        Reporting.Result<?> result, String name) {
+        final Reporting.Error error = result.getError();
+        error.prependSegment(new Reporting.NameSegment(name));
+        return Reporting.Result.failure(error);
+      }
+
+      /**
+       * Mark the error of {@code result} as coming from the item at {@code index}.
+       */
+      private static <T> Reporting.Result<T> prependIndex(
+        Reporting.Result<?> result, int index) {
+        final Reporting.Error error = result.getError();
+        error.prependSegment(new Reporting.IndexSegment(index));
+        return Reporting.Result.failure(error);
+      }
+
+      /**
+       * Report that {@code node} is no JSON object.
+       */
+      private static <T> Reporting.Result<T> notAJsonObject(JsonNode node) {
+        return Reporting.Result.failure(
+          new Reporting.Error(
+            "Expected a JsonObject, but got " +
+            (node == null ? "null" : node.getNodeType())));
+      }
+
+      /**
+       * Report that {@code node} is no JSON array.
+       */
+      private static <T> Reporting.Result<T> notAJsonArray(JsonNode node) {
+        return Reporting.Result.failure(
+          new Reporting.Error(
+            "Expected a JsonArray, but got " + node.getNodeType()));
+      }
+
+      /**
+       * Report a property which the class does not have.
+       */
+      private static <T> Reporting.Result<T> unexpectedProperty(String name) {
+        return Reporting.Result.failure(
+          new Reporting.Error("Unexpected property: " + name));
+      }
+
+      /**
+       * Report a required property which the JSON object did not give.
+       */
+      private static <T> Reporting.Result<T> missingRequiredProperty(String name) {
+        return Reporting.Result.failure(
+          new Reporting.Error(
+            "Required property \"" + name + "\" is missing"));
+      }
+
+      /**
+       * Extract the {@code modelType} property of {@code node} as a string.
+       *
+       * <p>This is the only place which knows how the model type is spelled on
+       * the wire. Both the dispatch on the model type and its check in a concrete
+       * class go through it.
+       *
+       * @param node JSON object to be inspected
+       */
+      private static Reporting.Result<String> tryModelTypeFrom(JsonNode node) {
+        final JsonNode modelTypeNode = node.get("modelType");
+        if (modelTypeNode == null) {
+          return missingRequiredProperty("modelType");
+        }
+
+        final Reporting.Result<String> result = tryStringFrom(modelTypeNode);
+        if (result.isError()) {
+          return prependName(result, "modelType");
+        }
+
+        return result;
+      }
+
+      /**
+       * Check that {@code node} gives the {@code expected} model type, and return
+       * the error if it does not.
+       *
+       * <p>The model type is checked before the properties are read, so that a wrong
+       * one is reported without de-serializing any of them first, and so that
+       * the property loop carries nothing but the properties.
+       *
+       * @param node JSON object to be inspected
+       * @param expected model type of the class being de-serialized
+       */
+      private static Reporting.Error checkModelType(JsonNode node, String expected) {
+        final Reporting.Result<String> result = tryModelTypeFrom(node);
+        if (result.isError()) {
+          return result.getError();
+        }
+
+        final String modelType = result.getResult();
+        if (!modelType.equals(expected)) {
+          final Reporting.Error error = new Reporting.Error(
+            "Expected the model type '" + expected + "', " +
+            "but got '" + modelType + "'");
+          // NOTE (mristin):
+          // A wrong model type is reported at the instance, as an unknown one is,
+          // and as in the other SDKs.
+          return error;
+        }
+
+        return null;
+      }
+
+      /**
+       * Parse {@code node} as a JSON array, and every of its items with
+       * {@code parseItem}.
+       *
+       * @param node JSON node to be parsed
+       * @param parseItem to parse a single item of the array
+       */
+      private static <T> Reporting.Result<List<T>> parseArray(
+        JsonNode node,
+        Function<JsonNode, Reporting.Result<? extends T>> parseItem) {
+        if (!node.isArray()) {
+          return notAJsonArray(node);
+        }
+
+        final List<T> result = new ArrayList<>(node.size());
+
+        int index = 0;
+        for (JsonNode item : node) {
+          final Reporting.Result<? extends T> parsedItem = parseItem.apply(item);
+          if (parsedItem.isError()) {
+            return prependIndex(parsedItem, index);
+          }
+
+          result.add(parsedItem.getResult());
+          index++;
+        }
+
+        return Reporting.Result.success(result);
+      }
+
+      /**
+       * Parse {@code node} as a list of {@code IItem}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<List<IItem>> parseListOf_IItem(JsonNode node) {
+        return parseArray(node, _DeserializeImplementation::tryIItemFrom);
+      }
+
+      /**
+       * Parse {@code node} as a list of {@code ISomeItem}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<List<ISomeItem>> parseListOf_ISomeItem(JsonNode node) {
+        return parseArray(node, _DeserializeImplementation::tryISomeItemFrom);
+      }
+
+      /**
+       * Parse {@code node} as a list of {@code ISpecialItem}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<List<ISpecialItem>> parseListOf_ISpecialItem(JsonNode node) {
+        return parseArray(node, _DeserializeImplementation::trySpecialItemFrom);
+      }
+
+      /**
+       * Deserialize an instance of IItem by dispatching
+       * based on {@code modelType} property of the {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static Reporting.Result<? extends IItem> tryIItemFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        final Reporting.Result<String> modelTypeResult = tryModelTypeFrom(node);
+        if (modelTypeResult.isError()) {
+          return modelTypeResult.castTo(IItem.class);
+        }
+
+        switch (modelTypeResult.getResult()) {
+          case "SomeItem":
+            return trySomeItemFromObject(node);
+          case "SpecialItem":
+            return trySpecialItemFromObject(node);
+          default: {
+            final Reporting.Error error = new Reporting.Error(
+              "Unexpected model type for IItem: " + modelTypeResult.getResult());
+            return Reporting.Result.failure(error);
+          }
+        }
+      }
+
+      /**
+       * Deserialize an instance of ISomeItem by dispatching
+       * based on {@code modelType} property of the {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static Reporting.Result<? extends ISomeItem> tryISomeItemFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        final Reporting.Result<String> modelTypeResult = tryModelTypeFrom(node);
+        if (modelTypeResult.isError()) {
+          return modelTypeResult.castTo(ISomeItem.class);
+        }
+
+        switch (modelTypeResult.getResult()) {
+          case "SpecialItem":
+            return trySpecialItemFromObject(node);
+          case "SomeItem":
+            return trySomeItemFromObject(node);
+          default: {
+            final Reporting.Error error = new Reporting.Error(
+              "Unexpected model type for ISomeItem: " + modelTypeResult.getResult());
+            return Reporting.Result.failure(error);
+          }
+        }
+      }
+
+      /**
+       * Deserialize an instance of SomeItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<SomeItem> trySomeItemFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        final Reporting.Error modelTypeError = checkModelType(node, "SomeItem");
+        if (modelTypeError != null) {
+          return Reporting.Result.failure(modelTypeError);
+        }
+
+        return trySomeItemFromObject(node);
+      }
+
+      /**
+       * Deserialize an instance of SomeItem from the JSON object {@code node} whose
+       * model type has already been checked.
+       *
+       * @param node JSON object to be parsed
+       */
+      private static Reporting.Result<SomeItem> trySomeItemFromObject(JsonNode node) {
+        String theName = null;
+        String theNickname = null;
+
+        for (Iterator<Map.Entry<String, JsonNode>> iterator = node.fields(); iterator.hasNext(); ) {
+          final Map.Entry<String, JsonNode> keyValue = iterator.next();
+          final String key = keyValue.getKey();
+          final JsonNode value = keyValue.getValue();
+
+          switch (key) {
+            case "name": {
+              final Reporting.Result<? extends String> parsed = tryStringFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theName = parsed.getResult();
+              break;
+            }
+            case "nickname": {
+              final Reporting.Result<? extends String> parsed = tryStringFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theNickname = parsed.getResult();
+              break;
+            }
+            case "modelType":
+              // The model type has already been checked before the loop.
+              break;
+            default:
+              return unexpectedProperty(key);
+          }
+        }
+
+        if (theName == null) {
+          return missingRequiredProperty("name");
+        }
+
+        return Reporting.Result.success(new SomeItem(
+          theName,
+          theNickname));
+      }
+
+      /**
+       * Deserialize an instance of SpecialItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<SpecialItem> trySpecialItemFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        final Reporting.Error modelTypeError = checkModelType(node, "SpecialItem");
+        if (modelTypeError != null) {
+          return Reporting.Result.failure(modelTypeError);
+        }
+
+        return trySpecialItemFromObject(node);
+      }
+
+      /**
+       * Deserialize an instance of SpecialItem from the JSON object {@code node} whose
+       * model type has already been checked.
+       *
+       * @param node JSON object to be parsed
+       */
+      private static Reporting.Result<SpecialItem> trySpecialItemFromObject(JsonNode node) {
+        String theName = null;
+        Long theLevel = null;
+        String theNickname = null;
+
+        for (Iterator<Map.Entry<String, JsonNode>> iterator = node.fields(); iterator.hasNext(); ) {
+          final Map.Entry<String, JsonNode> keyValue = iterator.next();
+          final String key = keyValue.getKey();
+          final JsonNode value = keyValue.getValue();
+
+          switch (key) {
+            case "name": {
+              final Reporting.Result<? extends String> parsed = tryStringFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theName = parsed.getResult();
+              break;
+            }
+            case "level": {
+              final Reporting.Result<? extends Long> parsed = tryLongFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theLevel = parsed.getResult();
+              break;
+            }
+            case "nickname": {
+              final Reporting.Result<? extends String> parsed = tryStringFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theNickname = parsed.getResult();
+              break;
+            }
+            case "modelType":
+              // The model type has already been checked before the loop.
+              break;
+            default:
+              return unexpectedProperty(key);
+          }
+        }
+
+        if (theName == null) {
+          return missingRequiredProperty("name");
+        }
+
+        if (theLevel == null) {
+          return missingRequiredProperty("level");
+        }
+
+        return Reporting.Result.success(new SpecialItem(
+          theName,
+          theLevel,
+          theNickname));
+      }
+
+      /**
+       * Deserialize an instance of Container from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<Container> tryContainerFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        List<IItem> theItems = null;
+        List<ISomeItem> theSomeItems = null;
+        List<ISpecialItem> theSpecialItems = null;
+
+        for (Iterator<Map.Entry<String, JsonNode>> iterator = node.fields(); iterator.hasNext(); ) {
+          final Map.Entry<String, JsonNode> keyValue = iterator.next();
+          final String key = keyValue.getKey();
+          final JsonNode value = keyValue.getValue();
+
+          switch (key) {
+            case "items": {
+              final Reporting.Result<List<IItem>> parsed = parseListOf_IItem(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theItems = parsed.getResult();
+              break;
+            }
+            case "someItems": {
+              final Reporting.Result<List<ISomeItem>> parsed = parseListOf_ISomeItem(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theSomeItems = parsed.getResult();
+              break;
+            }
+            case "specialItems": {
+              final Reporting.Result<List<ISpecialItem>> parsed = parseListOf_ISpecialItem(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theSpecialItems = parsed.getResult();
+              break;
+            }
+            default:
+              return unexpectedProperty(key);
+          }
+        }
+
+        if (theItems == null) {
+          return missingRequiredProperty("items");
+        }
+
+        if (theSomeItems == null) {
+          return missingRequiredProperty("someItems");
+        }
+
+        return Reporting.Result.success(new Container(
+          theItems,
+          theSomeItems,
+          theSpecialItems));
+      }
+
+      /**
+       * Deserialize an instance of Wrapper from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      private static Reporting.Result<Wrapper> tryWrapperFrom(JsonNode node) {
+        if (node == null || !node.isObject()) {
+          return notAJsonObject(node);
+        }
+
+        IContainer theContainer = null;
+
+        for (Iterator<Map.Entry<String, JsonNode>> iterator = node.fields(); iterator.hasNext(); ) {
+          final Map.Entry<String, JsonNode> keyValue = iterator.next();
+          final String key = keyValue.getKey();
+          final JsonNode value = keyValue.getValue();
+
+          switch (key) {
+            case "container": {
+              final Reporting.Result<? extends IContainer> parsed = tryContainerFrom(value);
+              if (parsed.isError()) {
+                return prependName(parsed, key);
+              }
+              theContainer = parsed.getResult();
+              break;
+            }
+            default:
+              return unexpectedProperty(key);
+          }
+        }
+
+        if (theContainer == null) {
+          return missingRequiredProperty("container");
+        }
+
+        return Reporting.Result.success(new Wrapper(
+          theContainer));
+      }
+    }
+
+    /**
+    * Represent a critical error during the deserialization.
+    */
+    @SuppressWarnings("serial")
+      public static class DeserializeException extends RuntimeException {
+        private final String path;
+        private final String reason;
+
+        public DeserializeException(String path, String reason) {
+          super(reason + " at: " + ("".equals(path) ? "the beginning" : path));
+          this.path = path;
+          this.reason = reason;
+        }
+
+        public Optional<String> getPath() {
+          return Optional.ofNullable(path);
+        }
+
+        public Optional<String> getReason() {
+          return Optional.ofNullable(reason);
+        }
+      }
+
+    /**
+    * Represent a critical error during the serialization.
+    */
+    @SuppressWarnings("serial")
+      public static class SerializeException extends RuntimeException {
+        private final String path;
+        private final String reason;
+
+        public SerializeException(String path, String reason) {
+          super(reason + " at: " + ("".equals(path) ? "the beginning" : path));
+          this.path = path;
+          this.reason = reason;
+        }
+
+        public Optional<String> getPath() {
+          return Optional.ofNullable(path);
+        }
+
+        public Optional<String> getReason() {
+          return Optional.ofNullable(reason);
+        }
+      }
+
+    /**
+    * Signal a failure of the serialization, carrying the path to the culprit.
+    *
+    * <p>The path is built as the stack unwinds -- every container prepends
+    * the one segment it knows, the property its name and the list the index
+    * of the item -- which is why this can not be a
+    * {@link SerializeException} already: that one renders its message in
+    * its constructor, so its path has to be complete by then.
+    * {@link Serialize#toJsonObject} renders and converts.
+    */
+    @SuppressWarnings("serial")
+      private static class _SerializeFailure extends RuntimeException {
+        private final Reporting.Error error;
+
+        _SerializeFailure(Reporting.Error error) {
+          super(error.getCause());
+          this.error = error;
+        }
+
+        Reporting.Error getError() {
+          return error;
+        }
+      }
+
+    /**
+     * Deserialize instances of meta-model classes from JSON nodes.
+     *
+     * Here is an example how to parse an instance of IItem:
+     * <pre>{@code
+     * String someString = "... some JSON ...";
+     * ObjectMapper objectMapper = new ObjectMapper();
+     * JsonNode node = objectMapper.readTree(someString);
+     * IItem anInstance = Deserialize.deserializeIItem(
+     *   node);
+     * }</pre>
+     */
+    public static class Deserialize
+    {
+      /**
+       * Deserialize an instance of IItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static IItem deserializeIItem(JsonNode node) {
+        final Reporting.Result<? extends IItem> result =
+          _DeserializeImplementation.tryIItemFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+
+      /**
+       * Deserialize an instance of ISomeItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static ISomeItem deserializeISomeItem(JsonNode node) {
+        final Reporting.Result<? extends ISomeItem> result =
+          _DeserializeImplementation.tryISomeItemFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+
+      /**
+       * Deserialize an instance of SomeItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static SomeItem deserializeSomeItem(JsonNode node) {
+        final Reporting.Result<? extends SomeItem> result =
+          _DeserializeImplementation.trySomeItemFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+
+      /**
+       * Deserialize an instance of SpecialItem from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static SpecialItem deserializeSpecialItem(JsonNode node) {
+        final Reporting.Result<? extends SpecialItem> result =
+          _DeserializeImplementation.trySpecialItemFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+
+      /**
+       * Deserialize an instance of Container from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static Container deserializeContainer(JsonNode node) {
+        final Reporting.Result<? extends Container> result =
+          _DeserializeImplementation.tryContainerFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+
+      /**
+       * Deserialize an instance of Wrapper from {@code node}.
+       *
+       * @param node JSON node to be parsed
+       */
+      public static Wrapper deserializeWrapper(JsonNode node) {
+        final Reporting.Result<? extends Wrapper> result =
+          _DeserializeImplementation.tryWrapperFrom(
+            node);
+
+        return result.onError(error -> {
+          throw new DeserializeException(
+            Reporting.generateJsonPath(error.getPathSegments()),
+            error.getCause());
+        });
+      }
+    }
+
+    private static class _Transformer extends AbstractTransformer<JsonNode> {
+      /**
+       * Dispatch the serialization over the run-time type of an instance.
+       *
+       * <p>The transformer carries no state, so a single instance serves
+       * the whole program.
+       */
+      private static final _Transformer INSTANCE = new _Transformer();
+
+      /**
+       * Serialize {@code that} into a JSON object.
+       *
+       * <p>Which JSON object that is, is decided by the run-time type of
+       * {@code that}, so this one serializer serves every abstract class, every
+       * concrete class with descendants, and the item of a list or of a tuple of
+       * any class at all. The de-serialization, which has to decide what to
+       * construct before it has read anything, needs a dispatcher per interface
+       * instead.
+       *
+       * <p>It is static, so that a composed serializer -- which is static as well,
+       * since it carries no state either -- can reach it.
+       */
+      static JsonNode transformClass(IClass that) {
+        return INSTANCE.transform(that);
+      }
+
+      /**
+       * Convert a single value into a JSON node.
+       */
+      @FunctionalInterface
+      private interface Serializer<T> {
+        JsonNode serialize(T that);
+      }
+
+      /**
+       * Set the property {@code jsonName} of {@code result} to
+       * {@code that}, serialized by {@code serialize}.
+       *
+       * <p>{@code getterName} names the property on the path of a failure. It is
+       * the getter, and not the JSON property: a serialization error is reported
+       * on an <em>instance</em>, which the caller holds, and not on a document
+       * which has not been written yet.
+       */
+      private static <T> void setProperty(
+        ObjectNode result,
+        String jsonName,
+        String getterName,
+        T that,
+        Serializer<? super T> serialize) {
+        try {
+          result.set(jsonName, serialize.serialize(that));
+        } catch (_SerializeFailure failure) {
+          failure.getError().prependSegment(
+            new Reporting.NameSegment(getterName));
+          throw failure;
+        }
+      }
+
+      /**
+       * Set the property {@code jsonName} of {@code result} if {@code that}
+       * has been given, and set nothing at all otherwise.
+       *
+       * <p>The {@link Optional} is taken apart here, once, instead of at every
+       * optional property: asking it and then unwrapping it at the call site would
+       * call the getter twice, and every call allocates an {@link Optional} of
+       * its own.
+       */
+      private static <T> void setOptionalProperty(
+        ObjectNode result,
+        String jsonName,
+        String getterName,
+        Optional<T> that,
+        Serializer<? super T> serialize) {
+        final T value = that.orElse(null);
+        if (value != null) {
+          setProperty(result, jsonName, getterName, value, serialize);
+        }
+      }
+
+      /**
+       * Convert {@code that} string to a JSON value.
+       *
+       * <p>See the note on {@link #boolToJsonNode} on why this wrapper exists.
+       *
+       * @param that value to be converted
+       */
+      private static JsonNode stringToJsonNode(String that) {
+        return JsonNodeFactory.instance.textNode(that);
+      }
+
+      /**
+       * Convert {@code that} 64-bit long integer to a JSON value.
+       *
+       * @param that value to be converted
+       */
+      private static JsonNode longToJsonNode(Long that) {
+        // NOTE (mristin):
+        // Outside this range an integer can not be exactly represented as a 64-bit
+        // floating-point number, which is what the JSON de-serializers of the other
+        // languages read a number into.
+        final long primitiveThat = that.longValue();
+        if (primitiveThat < -9007199254740991L || primitiveThat > 9007199254740991L) {
+          throw new _SerializeFailure(
+            new Reporting.Error(
+              "The integer can not be serialized to JSON as it is outside "
+                + "the range [-2^53 + 1, 2^53 - 1]: " + that));
+        }
+        return JsonNodeFactory.instance.numberNode(that);
+      }
+
+      /**
+       * Serialize every item of {@code that} into a JSON array.
+       *
+       * @param that to be serialized
+       */
+      private static ArrayNode serializeListOf_IClass(
+        List<? extends IClass> that) {
+        final ArrayNode result = JsonNodeFactory.instance.arrayNode();
+        int i = 0;
+        for (IClass item : that) {
+          try {
+            result.add(transformClass(item));
+          } catch (_SerializeFailure failure) {
+            failure.getError().prependSegment(
+              new Reporting.IndexSegment(i));
+            throw failure;
+          }
+          i++;
+        }
+        return result;
+      }
+
+      @Override
+      public JsonNode transformSomeItem(
+        ISomeItem that
+      ) {
+        final ObjectNode result = JsonNodeFactory.instance.objectNode();
+
+        setProperty(result, "name", "getName()", that.getName(), _Transformer::stringToJsonNode);
+
+        setOptionalProperty(
+          result, "nickname", "getNickname()",
+          that.getNickname(), _Transformer::stringToJsonNode);
+
+        result.put("modelType", "SomeItem");
+
+        return result;
+      }
+
+      @Override
+      public JsonNode transformSpecialItem(
+        ISpecialItem that
+      ) {
+        final ObjectNode result = JsonNodeFactory.instance.objectNode();
+
+        setProperty(result, "name", "getName()", that.getName(), _Transformer::stringToJsonNode);
+
+        setOptionalProperty(
+          result, "nickname", "getNickname()",
+          that.getNickname(), _Transformer::stringToJsonNode);
+
+        setProperty(result, "level", "getLevel()", that.getLevel(), _Transformer::longToJsonNode);
+
+        result.put("modelType", "SpecialItem");
+
+        return result;
+      }
+
+      @Override
+      public JsonNode transformContainer(
+        IContainer that
+      ) {
+        final ObjectNode result = JsonNodeFactory.instance.objectNode();
+
+        setProperty(
+          result, "items", "getItems()",
+          that.getItems(), _Transformer::serializeListOf_IClass);
+
+        setProperty(
+          result, "someItems", "getSomeItems()",
+          that.getSomeItems(), _Transformer::serializeListOf_IClass);
+
+        setOptionalProperty(
+          result, "specialItems", "getSpecialItems()",
+          that.getSpecialItems(), _Transformer::serializeListOf_IClass);
+
+        return result;
+      }
+
+      @Override
+      public JsonNode transformWrapper(
+        IWrapper that
+      ) {
+        final ObjectNode result = JsonNodeFactory.instance.objectNode();
+
+        setProperty(
+          result, "container", "getContainer()",
+          that.getContainer(), _Transformer::transformClass);
+
+        return result;
+      }
+    }
+
+    /**
+     * Serialize instances of meta-model classes to JSON elements.
+     *
+     * Here is an example how to serialize an instance of IItem:
+     * <pre>{@code
+     * IItem anInstance = new IItem(
+     *     // ... some constructor arguments ...
+     * );
+     * JsonNode element = Jsonization.Serialize.toJsonObject(
+     *     anInstance));
+     * }</pre>
+     */
+    public static class Serialize
+    {
+      /**
+       * Serialize an instance of the meta-model into a JSON object.
+       *
+       * @throws SerializeException if a value within {@code that} instance can
+       * not be represented in JSON
+       */
+      public static JsonNode toJsonObject(IClass that) {
+        try {
+          return _Transformer.transformClass(that);
+        } catch (_SerializeFailure failure) {
+          final Reporting.Error error = failure.getError();
+          throw new SerializeException(
+            Reporting.generateJavaPath(error.getPathSegments()),
+            error.getCause());
+        }
+      }
+    }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/reporting/Reporting.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/reporting/Reporting.java
new file mode 100644
index 000000000..647e421f2
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/reporting/Reporting.java
@@ -0,0 +1,345 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.reporting;
+
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.Collections;
+import java.util.Collection;
+import java.util.List;
+import java.util.LinkedList;
+import java.util.Objects;
+import java.util.function.Function;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Provide reporting for de/serialization and verification.
+ */
+public class Reporting
+{
+    /**
+     * Capture a path segment of a value in a model.
+     */
+    public static abstract class Segment {
+        // Intentionally empty.
+    }
+
+    public static class NameSegment extends Segment {
+        private final String name;
+        public NameSegment(String name) {
+            this.name = Objects.requireNonNull(name,
+                "Argument \"name\" must be non-null.");
+        }
+        public String getName(){
+            return name;
+        }
+    }
+
+    public static class IndexSegment extends Segment{
+        private final Integer index;
+        public IndexSegment(int index) {
+            this.index = index;
+        }
+        public Integer getIndex(){
+            return index;
+        }
+    }
+
+    /**
+     * Capture a member of an open JSON-able object on a path to
+     * the erroneous value.
+     *
+     * <p>Unlike a {@link NameSegment}, which names a property of one of our
+     * classes, a key is known only at run time, and can be any string at all.
+     */
+    public static class KeySegment extends Segment {
+        private final String key;
+        public KeySegment(String key) {
+            this.key = Objects.requireNonNull(key,
+                "Argument \"key\" must be non-null.");
+        }
+        public String getKey(){
+            return key;
+        }
+    }
+
+    private static final Pattern variableNameRe = Pattern.compile("^[a-zA-Z_][a-zA-Z_0-9]*$");
+
+    /**
+     * Generate a JSON Path based on the path segments.
+     *
+     * <p>See, for example, this page for more information on JSON path:
+     * <a href="https://support.smartbear.com/alertsite/docs/monitors/api/endpoint/jsonpath.html"
+     * >https://support.smartbear.com/alertsite/docs/monitors/api/endpoint/jsonpath.html</a>
+     */
+    public static String generateJsonPath(Collection<Segment> segments) {
+        ArrayList<String> parts = new ArrayList<>(segments.size());
+        int i = 0;
+
+        for (Segment segment : segments) {
+            String part;
+
+            if (segment instanceof NameSegment) {
+                NameSegment nameSegment = (NameSegment) segment;
+                Matcher m = variableNameRe.matcher(nameSegment.getName());
+
+                if (m.matches()) {
+                    part = (i == 0) ? nameSegment.getName() : "." + nameSegment.getName();
+                } else {
+                    part = "[\"" + escapeForJsonString(nameSegment.getName()) + "\"]";
+                }
+            } else if (segment instanceof IndexSegment) {
+                IndexSegment indexSegment = (IndexSegment) segment;
+                part = "[" + indexSegment.getIndex() + "]";
+            } else if (segment instanceof KeySegment) {
+                // A key is no name of a property of one of our classes, so it is
+                // always bracketed, whatever it looks like.
+                KeySegment keySegment = (KeySegment) segment;
+                part = "[\"" + escapeForJsonString(keySegment.getKey()) + "\"]";
+            } else {
+                throw new RuntimeException(
+                    "Unexpected segment type: " + segment.getClass().getSimpleName()
+                );
+            }
+
+            parts.add(part);
+            i++;
+        }
+        return String.join("", parts);
+    }
+
+    /**
+     * Escape the characters which a JSON string may not hold as they are.
+     *
+     * <p>The control characters without a short escape are written as Unicode
+     * escapes, as {@code JSON.stringify} does.
+     */
+    private static String escapeForJsonString(String text) {
+        StringBuilder builder = new StringBuilder(text.length());
+        for (int i = 0; i < text.length(); i++) {
+            char character = text.charAt(i);
+            switch (character) {
+                case '\\':
+                    builder.append("\\\\");
+                    break;
+                case '"':
+                    builder.append("\\\"");
+                    break;
+                case '\b':
+                    builder.append("\\b");
+                    break;
+                case '\f':
+                    builder.append("\\f");
+                    break;
+                case '\n':
+                    builder.append("\\n");
+                    break;
+                case '\r':
+                    builder.append("\\r");
+                    break;
+                case '\t':
+                    builder.append("\\t");
+                    break;
+                default:
+                    if (character < 0x20) {
+                        builder.append(String.format("\\u%04x", (int) character));
+                    } else {
+                        builder.append(character);
+                    }
+                    break;
+            }
+        }
+        return builder.toString();
+    }
+
+    /**
+     * Escape special characters for XPath.
+     */
+    private static String escapeForXPath(String text) {
+    return text
+            .replace("&", "&amp;")
+            .replace("/", "&#47;")
+            .replace("<", "&lt;")
+            .replace(">", "&gt;")
+            .replace("\"", "&quot;")
+            .replace("'", "&apos;");
+    }
+
+    /**
+     * Generate a relative XPath based on the path segments.
+     *
+     * <p>This method leaves out the leading slash ('/'). This is helpful if
+     * to embed the error report in a larger document with a prefix etc.
+     */
+    public static String generateRelativeXPath(Collection<Segment> segments) {
+        final List<String> parts = new ArrayList<>();
+        segments.forEach(segment -> {
+            String part;
+            if (segment instanceof NameSegment) {
+                final NameSegment nameSegment = ((NameSegment) segment);
+                final String name = nameSegment.getName();
+                part = escapeForXPath(name);
+            } else if (segment instanceof IndexSegment) {
+                final IndexSegment indexSegment = ((IndexSegment) segment);
+                // NOTE (mristin):
+                // XPath counts the elements starting at one, while our indices start at zero.
+                final int index = indexSegment.getIndex();
+                part = "*[" + (index + 1) + "]";
+            } else if (segment instanceof KeySegment) {
+                // A JSON-able object is written as an XML-RPC <struct>, which holds
+                // the key of a member in a <name> child element, and not in
+                // an attribute, so the XPath has to match on that child element.
+                final KeySegment keySegment = ((KeySegment) segment);
+                part = "member[name=\"" +
+                    escapeForXPath(keySegment.getKey()) + "\"]";
+            } else {
+                throw new IllegalArgumentException("Unexpected segment type: " +
+                    segment.getClass().getSimpleName());
+            }
+            parts.add(part);
+        });
+        return String.join("/", parts);
+    }
+
+    /**
+     * Generate a Java access path based on the path segments.
+     *
+     * <p>The name segments are expected to be the getters of the properties in
+     * Java, parentheses included. This is the path to report where in an
+     * <em>instance</em> something went wrong -- on the serialization, say,
+     * where the caller holds the instance, and not a document which has not
+     * been written yet.
+     *
+     * <p>Unlike the JSON path and the XPath, this one is a Java expression on
+     * that instance which the caller can paste, as a list and a JSON-able value
+     * happen to agree on {@code get}: an item of a list, an item of
+     * a JSON-able array and a member of a JSON-able object are all reached with
+     * it, <em>e.g.</em>,
+     * {@code getSubmodelElements().get(0).getValue().get("some key")}.
+     */
+    public static String generateJavaPath(Collection<Segment> segments) {
+        final List<String> parts = new ArrayList<>(segments.size());
+        int i = 0;
+
+        for (Segment segment : segments) {
+            final String part;
+
+            if (segment instanceof NameSegment) {
+                final NameSegment nameSegment = ((NameSegment) segment);
+                part = (i == 0)
+                    ? nameSegment.getName()
+                    : "." + nameSegment.getName();
+            } else if (segment instanceof IndexSegment) {
+                final IndexSegment indexSegment = ((IndexSegment) segment);
+                part = ".get(" + indexSegment.getIndex() + ")";
+            } else if (segment instanceof KeySegment) {
+                final KeySegment keySegment = ((KeySegment) segment);
+                part = ".get(\"" + escapeForJsonString(keySegment.getKey()) + "\")";
+            } else {
+                throw new IllegalArgumentException("Unexpected segment type: " +
+                    segment.getClass().getSimpleName());
+            }
+
+            parts.add(part);
+            i++;
+        }
+        return String.join("", parts);
+    }
+
+    /**
+     * Represent an error during the deserialization or the verification.
+     */
+    public static class Error {
+        private final Deque<Segment> pathSegments = new LinkedList<>();
+        private final String cause;
+
+        public Error(String cause) {
+            this.cause = cause;
+        }
+
+        public void prependSegment(Segment segment) {
+            pathSegments.addFirst(segment);
+        }
+
+        public String getCause() {
+            return cause;
+        }
+
+        public Collection<Segment> getPathSegments() {
+            return pathSegments;
+        }
+    }
+
+    /**
+     * Represent the outcome of a de/serialization or a verification step.
+     *
+     * <p>This is shared by JSON de/serialization, XML de/serialization and
+     * verification, all of which propagate an {@link Error} instead of relying
+     * on exceptions for the common (successful) case.
+     */
+    public static class Result<T> {
+        private final T result;
+        private final Error error;
+        private final boolean success;
+
+        private Result(T result, Error error, boolean success) {
+            this.result = result;
+            this.error = error;
+            this.success = success;
+        }
+
+        public static <T> Result<T> success(T result) {
+            if (result == null) throw new IllegalArgumentException("Result must not be null.");
+            return new Result<>(result, null, true);
+        }
+
+        public static <T> Result<T> failure(Error error) {
+            if (error == null) throw new IllegalArgumentException("Error must not be null.");
+            return new Result<>(null, error, false);
+        }
+
+        @SuppressWarnings("unchecked")
+        public <I> Result<I> castTo(Class<I> type) {
+            if (isError() || type.isInstance(result)) return (Result<I>) this;
+            throw new IllegalStateException("Result of type "
+                + result.getClass().getName()
+                + " is not an instance of "
+                + type.getName());
+        }
+
+        public T getResult() {
+            if (!isSuccess()) throw new IllegalStateException("Result is not present.");
+            return result;
+        }
+
+        public boolean isSuccess() {
+            return success;
+        }
+
+        public boolean isError() {
+            return !success;
+        }
+
+        public Error getError() {
+            if (isSuccess()) throw new IllegalStateException("Result is present.");
+            return error;
+        }
+
+        public <R> R map(Function<T, R> successFunction, Function<Error, R> errorFunction) {
+            return isSuccess() ? successFunction.apply(result) : errorFunction.apply(error);
+        }
+
+        public T onError(Function<Error, T> errorFunction) {
+            return map(Function.identity(), errorFunction);
+        }
+    }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/stringification/Stringification.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/stringification/Stringification.java
new file mode 100644
index 000000000..f38a60c28
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/stringification/Stringification.java
@@ -0,0 +1,22 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.stringification;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import dummy.types.enums.*;
+
+public class Stringification {
+  
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/enums/IEnum.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/enums/IEnum.java
new file mode 100644
index 000000000..3efe6c3f3
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/enums/IEnum.java
@@ -0,0 +1,24 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.enums;
+
+/**
+ * Represent a literal of an enumeration of the meta-model.
+ */
+public interface IEnum {
+  /**
+   * Get the string representation of this literal.
+   *
+   * <p>This is the text the literal is de/serialized as, which is in general
+   * not its {@link Enum#name()}.
+   */
+  String literalText();
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Container.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Container.java
new file mode 100644
index 000000000..bbf25428b
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Container.java
@@ -0,0 +1,261 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.impl;
+
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.Objects;
+import java.util.Iterator;
+import java.util.Spliterator;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+import dummy.types.model.IContainer;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+public class Container implements IContainer {
+  private List<IItem> items;
+
+  private List<ISomeItem> someItems;
+
+  private List<ISpecialItem> specialItems;
+
+  public Container(
+    List<IItem> items,
+    List<ISomeItem> someItems) {
+    this.items = Objects.requireNonNull(
+      items,
+      "Argument \"items\" must be non-null.");
+    this.someItems = Objects.requireNonNull(
+      someItems,
+      "Argument \"someItems\" must be non-null.");
+  }
+
+  public Container(
+    List<IItem> items,
+    List<ISomeItem> someItems,
+    List<ISpecialItem> specialItems) {
+    this.items = Objects.requireNonNull(
+      items,
+      "Argument \"items\" must be non-null.");
+    this.someItems = Objects.requireNonNull(
+      someItems,
+      "Argument \"someItems\" must be non-null.");
+    this.specialItems = specialItems;
+  }
+
+  @Override
+  public List<IItem> getItems() {
+    return items;
+  }
+
+  @Override
+  public void setItems(List<IItem> items) {
+    this.items = Objects.requireNonNull(
+      items,
+      "Argument \"items\" must be non-null.");
+  }
+
+  @Override
+  public List<ISomeItem> getSomeItems() {
+    return someItems;
+  }
+
+  @Override
+  public void setSomeItems(List<ISomeItem> someItems) {
+    this.someItems = Objects.requireNonNull(
+      someItems,
+      "Argument \"someItems\" must be non-null.");
+  }
+
+  @Override
+  public Optional<List<ISpecialItem>> getSpecialItems() {
+    return Optional.ofNullable(specialItems);
+  }
+
+  @Override
+  public void setSpecialItems(List<ISpecialItem> specialItems) {
+    this.specialItems = specialItems;
+  }
+
+  /**
+   * Iterate over {@link Container#specialItems}, if set,
+   * and otherwise return an empty iterator.
+   */
+  public Iterable<ISpecialItem> overSpecialItemsOrEmpty() {
+    return getSpecialItems().orElseGet(Collections::emptyList);
+  }
+
+  /**
+   * Count the {@code items}.
+   *
+   * <p>The arguments of the methods are never generic, so only the sequences of
+   * {@link dummy.types.model.IItem} can be passed to it, but not the sequences of
+   * the descendants.
+   */
+  @Override
+  public Long countItems(
+    List<IItem> items
+  ) {
+    return (long) items.size();
+  }
+
+  /**
+   * Iterate recursively over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descend() {
+    return new _ContainerRecursiveIterable();
+  }
+
+  /**
+   * Iterate over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descendOnce() {
+    return new _ContainerIterable();
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch.
+   **/
+  @Override
+  public void accept(IVisitor visitor) {
+    visitor.visitContainer(this);
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT> void accept(
+      IVisitorWithContext<ContextT> visitor,
+      ContextT context) {
+    visitor.visitContainer(this, context);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch.
+   **/
+  @Override
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformContainer(this);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT, T> T transform(
+      ITransformerWithContext<ContextT, T> transformer,
+      ContextT context) {
+    return transformer.transformContainer(this, context);
+  }
+
+  private class _ContainerIterable implements Iterable<IClass> {
+    @Override
+    public Iterator<IClass> iterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.iterator();
+    }
+
+    @Override
+    public void forEach(Consumer<? super IClass> action) {
+      Stream<IClass> stream = stream();
+
+      stream.forEach(action);
+    }
+
+    @Override
+    public Spliterator<IClass> spliterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.spliterator();
+    }
+
+    private Stream<IClass> stream() {
+      Stream<IClass> memberStream = Stream.empty();
+
+      if (items != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_IItem(Container.this.items, false));
+      }
+
+      if (someItems != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_ISomeItem(Container.this.someItems, false));
+      }
+
+      if (specialItems != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_ISpecialItem(Container.this.specialItems, false));
+      }
+
+      return memberStream;
+    }
+  }
+
+  private class _ContainerRecursiveIterable implements Iterable<IClass> {
+    @Override
+    public Iterator<IClass> iterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.iterator();
+    }
+
+    @Override
+    public void forEach(Consumer<? super IClass> action) {
+      Stream<IClass> stream = stream();
+
+      stream.forEach(action);
+    }
+
+    @Override
+    public Spliterator<IClass> spliterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.spliterator();
+    }
+
+    private Stream<IClass> stream() {
+      Stream<IClass> memberStream = Stream.empty();
+
+      if (items != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_IItem(Container.this.items, true));
+      }
+
+      if (someItems != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_ISomeItem(Container.this.someItems, true));
+      }
+
+      if (specialItems != null) {
+        memberStream = Stream.concat(memberStream,
+          Descent.descendListOf_ISpecialItem(Container.this.specialItems, true));
+      }
+
+      return memberStream;
+    }
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Descent.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Descent.java
new file mode 100644
index 000000000..c9f078a8f
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Descent.java
@@ -0,0 +1,84 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.impl;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.model.*;
+import java.util.List;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+/**
+ * Descend into the containers which hold class instances.
+ *
+ * <p>Each method descends only one level, and calls the method of the items
+ * by name, so that the descent is composed of plain functions to any depth.
+ */
+final class Descent {
+  private Descent() {
+    // Prevent instantiation
+  }
+
+  /**
+   * Iterate over the class instances held by {@code that}.
+   *
+   * <p>If {@code recurse} is set, descend recursively into the instances
+   * as well.
+   */
+  static Stream<IClass> descendListOf_IItem(
+    List<IItem> that,
+    boolean recurse) {
+    if (!recurse) {
+      return that.stream().<IClass>map(item -> item);
+    }
+
+    return that.stream().flatMap(item ->
+      Stream.concat(Stream.<IClass>of(item),
+        StreamSupport.stream(item.descend().spliterator(), false)));
+  }
+
+  /**
+   * Iterate over the class instances held by {@code that}.
+   *
+   * <p>If {@code recurse} is set, descend recursively into the instances
+   * as well.
+   */
+  static Stream<IClass> descendListOf_ISomeItem(
+    List<ISomeItem> that,
+    boolean recurse) {
+    if (!recurse) {
+      return that.stream().<IClass>map(item -> item);
+    }
+
+    return that.stream().flatMap(item ->
+      Stream.concat(Stream.<IClass>of(item),
+        StreamSupport.stream(item.descend().spliterator(), false)));
+  }
+
+  /**
+   * Iterate over the class instances held by {@code that}.
+   *
+   * <p>If {@code recurse} is set, descend recursively into the instances
+   * as well.
+   */
+  static Stream<IClass> descendListOf_ISpecialItem(
+    List<ISpecialItem> that,
+    boolean recurse) {
+    if (!recurse) {
+      return that.stream().<IClass>map(item -> item);
+    }
+
+    return that.stream().flatMap(item ->
+      Stream.concat(Stream.<IClass>of(item),
+        StreamSupport.stream(item.descend().spliterator(), false)));
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SomeItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SomeItem.java
new file mode 100644
index 000000000..d2599933c
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SomeItem.java
@@ -0,0 +1,120 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.impl;
+
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.Objects;
+import dummy.types.model.ISomeItem;
+
+public class SomeItem implements ISomeItem {
+  private String name;
+
+  private String nickname;
+
+  public SomeItem(String name) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+  }
+
+  public SomeItem(
+    String name,
+    String nickname) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+    this.nickname = nickname;
+  }
+
+  @Override
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public void setName(String name) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+  }
+
+  @Override
+  public Optional<String> getNickname() {
+    return Optional.ofNullable(nickname);
+  }
+
+  @Override
+  public void setNickname(String nickname) {
+    this.nickname = nickname;
+  }
+
+  /**
+   * Iterate recursively over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descend() {
+    return Collections.emptyList();
+  }
+
+  /**
+   * Iterate over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descendOnce() {
+    return Collections.emptyList();
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch.
+   **/
+  @Override
+  public void accept(IVisitor visitor) {
+    visitor.visitSomeItem(this);
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT> void accept(
+      IVisitorWithContext<ContextT> visitor,
+      ContextT context) {
+    visitor.visitSomeItem(this, context);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch.
+   **/
+  @Override
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformSomeItem(this);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT, T> T transform(
+      ITransformerWithContext<ContextT, T> transformer,
+      ContextT context) {
+    return transformer.transformSomeItem(this, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SpecialItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SpecialItem.java
new file mode 100644
index 000000000..62b1ede0b
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/SpecialItem.java
@@ -0,0 +1,146 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.impl;
+
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.Objects;
+import dummy.types.model.ISpecialItem;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+public class SpecialItem implements ISpecialItem {
+  private String name;
+
+  private String nickname;
+
+  private Long level;
+
+  public SpecialItem(
+    String name,
+    Long level) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+    this.level = Objects.requireNonNull(
+      level,
+      "Argument \"level\" must be non-null.");
+  }
+
+  public SpecialItem(
+    String name,
+    Long level,
+    String nickname) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+    this.nickname = nickname;
+    this.level = Objects.requireNonNull(
+      level,
+      "Argument \"level\" must be non-null.");
+  }
+
+  @Override
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public void setName(String name) {
+    this.name = Objects.requireNonNull(
+      name,
+      "Argument \"name\" must be non-null.");
+  }
+
+  @Override
+  public Optional<String> getNickname() {
+    return Optional.ofNullable(nickname);
+  }
+
+  @Override
+  public void setNickname(String nickname) {
+    this.nickname = nickname;
+  }
+
+  @Override
+  public Long getLevel() {
+    return level;
+  }
+
+  @Override
+  public void setLevel(Long level) {
+    this.level = Objects.requireNonNull(
+      level,
+      "Argument \"level\" must be non-null.");
+  }
+
+  /**
+   * Iterate recursively over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descend() {
+    return Collections.emptyList();
+  }
+
+  /**
+   * Iterate over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descendOnce() {
+    return Collections.emptyList();
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch.
+   **/
+  @Override
+  public void accept(IVisitor visitor) {
+    visitor.visitSpecialItem(this);
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT> void accept(
+      IVisitorWithContext<ContextT> visitor,
+      ContextT context) {
+    visitor.visitSpecialItem(this, context);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch.
+   **/
+  @Override
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformSpecialItem(this);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT, T> T transform(
+      ITransformerWithContext<ContextT, T> transformer,
+      ContextT context) {
+    return transformer.transformSpecialItem(this, context);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Wrapper.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Wrapper.java
new file mode 100644
index 000000000..b373a45d5
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/impl/Wrapper.java
@@ -0,0 +1,176 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.impl;
+
+import dummy.common.*;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.Objects;
+import java.util.Iterator;
+import java.util.Spliterator;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+import dummy.types.model.IWrapper;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+public class Wrapper implements IWrapper {
+  private IContainer container;
+
+  public Wrapper(IContainer container) {
+    this.container = Objects.requireNonNull(
+      container,
+      "Argument \"container\" must be non-null.");
+  }
+
+  @Override
+  public IContainer getContainer() {
+    return container;
+  }
+
+  @Override
+  public void setContainer(IContainer container) {
+    this.container = Objects.requireNonNull(
+      container,
+      "Argument \"container\" must be non-null.");
+  }
+
+  /**
+   * Iterate recursively over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descend() {
+    return new _WrapperRecursiveIterable();
+  }
+
+  /**
+   * Iterate over all the class instances referenced from this instance.
+   */
+  public Iterable<IClass> descendOnce() {
+    return new _WrapperIterable();
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch.
+   **/
+  @Override
+  public void accept(IVisitor visitor) {
+    visitor.visitWrapper(this);
+  }
+
+  /**
+   * Accept the {@code visitor} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT> void accept(
+      IVisitorWithContext<ContextT> visitor,
+      ContextT context) {
+    visitor.visitWrapper(this, context);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch.
+   **/
+  @Override
+  public <T> T transform(ITransformer<T> transformer) {
+    return transformer.transformWrapper(this);
+  }
+
+  /**
+   * Accept the {@code transformer} to visit this instance for double dispatch
+   * with the {@code context}.
+   **/
+  @Override
+  public <ContextT, T> T transform(
+      ITransformerWithContext<ContextT, T> transformer,
+      ContextT context) {
+    return transformer.transformWrapper(this, context);
+  }
+
+  private class _WrapperIterable implements Iterable<IClass> {
+    @Override
+    public Iterator<IClass> iterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.iterator();
+    }
+
+    @Override
+    public void forEach(Consumer<? super IClass> action) {
+      Stream<IClass> stream = stream();
+
+      stream.forEach(action);
+    }
+
+    @Override
+    public Spliterator<IClass> spliterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.spliterator();
+    }
+
+    private Stream<IClass> stream() {
+      Stream<IClass> memberStream = Stream.empty();
+
+      if (container != null) {
+        memberStream = Stream.concat(memberStream,
+          Stream.<IClass>of(Wrapper.this.container));
+      }
+
+      return memberStream;
+    }
+  }
+
+  private class _WrapperRecursiveIterable implements Iterable<IClass> {
+    @Override
+    public Iterator<IClass> iterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.iterator();
+    }
+
+    @Override
+    public void forEach(Consumer<? super IClass> action) {
+      Stream<IClass> stream = stream();
+
+      stream.forEach(action);
+    }
+
+    @Override
+    public Spliterator<IClass> spliterator() {
+      Stream<IClass> stream = stream();
+
+      return stream.spliterator();
+    }
+
+    private Stream<IClass> stream() {
+      Stream<IClass> memberStream = Stream.empty();
+
+      if (container != null) {
+        memberStream = Stream.concat(memberStream,
+          Stream.concat(Stream.<IClass>of(Wrapper.this.container),
+            StreamSupport.stream(Wrapper.this.container.descend().spliterator(), false)));
+      }
+
+      return memberStream;
+    }
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IClass.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IClass.java
new file mode 100644
index 000000000..415bc598e
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IClass.java
@@ -0,0 +1,61 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.visitation.ITransformer;
+import dummy.visitation.ITransformerWithContext;
+import dummy.visitation.IVisitor;
+import dummy.visitation.IVisitorWithContext;
+import java.lang.Iterable;
+
+/**
+ * Represent a general class of the meta-model.
+ */
+public interface IClass {
+  /**
+   * Iterate over all the class instances referenced from this instance
+   * without further recursion.
+   */
+  Iterable<IClass> descendOnce();
+
+  /**
+   * Iterate recursively over all the class instances referenced from this instance.
+   */
+  Iterable<IClass> descend();
+
+  /**
+   * Accept the {@code visitor} to visit this instance
+   * for double dispatch.
+   */
+  void accept(IVisitor visitor);
+
+  /**
+   * Accept the visitor to visit this instance for double dispatch
+   * with the {@code context}.
+   */
+  <ContextT> void accept(
+      IVisitorWithContext<ContextT> visitor,
+      ContextT context);
+
+  /**
+   * Accept the {@code transformer} to transform this instance
+   * for double dispatch.
+   */
+  <T> T transform(ITransformer<T> transformer);
+
+  /**
+   * Accept the {@code transformer} to visit this instance
+   * for double dispatch with the {@code context}.
+   */
+  <ContextT, T> T transform(
+      ITransformerWithContext<ContextT, T> transformer,
+      ContextT context);
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IContainer.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IContainer.java
new file mode 100644
index 000000000..451868e8d
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IContainer.java
@@ -0,0 +1,47 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import dummy.types.model.IClass;
+import java.util.Optional;
+
+public interface IContainer extends IClass {
+  List<IItem> getItems();
+
+  void setItems(List<IItem> items);
+
+  List<ISomeItem> getSomeItems();
+
+  void setSomeItems(List<ISomeItem> someItems);
+
+  Optional<List<ISpecialItem>> getSpecialItems();
+
+  void setSpecialItems(List<ISpecialItem> specialItems);
+
+  /**
+   * Count the {@code items}.
+   *
+   * <p>The arguments of the methods are never generic, so only the sequences of
+   * {@link dummy.types.model.IItem} can be passed to it, but not the sequences of
+   * the descendants.
+   */
+  Long countItems(List<IItem> items);
+
+  /**
+   * Iterate over specialItems, if set, and otherwise return an empty enumerable.
+   */
+  Iterable<ISpecialItem> overSpecialItemsOrEmpty();
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IItem.java
new file mode 100644
index 000000000..80091570b
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IItem.java
@@ -0,0 +1,29 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import dummy.types.model.IClass;
+import java.util.Optional;
+
+public interface IItem extends IClass {
+  String getName();
+
+  void setName(String name);
+
+  Optional<String> getNickname();
+
+  void setNickname(String nickname);
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISomeItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISomeItem.java
new file mode 100644
index 000000000..047e582a6
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISomeItem.java
@@ -0,0 +1,22 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import dummy.types.model.IItem;
+
+public interface ISomeItem extends IItem {
+  // Intentionally empty.
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISpecialItem.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISpecialItem.java
new file mode 100644
index 000000000..62331a3b4
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/ISpecialItem.java
@@ -0,0 +1,25 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import dummy.types.model.ISomeItem;
+import java.util.Optional;
+
+public interface ISpecialItem extends ISomeItem {
+  Long getLevel();
+
+  void setLevel(Long level);
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IWrapper.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IWrapper.java
new file mode 100644
index 000000000..3c1e73640
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/types/model/IWrapper.java
@@ -0,0 +1,25 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.types.model;
+
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import java.util.List;
+import dummy.types.model.IClass;
+import java.util.Optional;
+
+public interface IWrapper extends IClass {
+  IContainer getContainer();
+
+  void setContainer(IContainer container);
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/verification/Verification.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/verification/Verification.java
new file mode 100644
index 000000000..d4797ea50
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/verification/Verification.java
@@ -0,0 +1,709 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.verification;
+
+import java.lang.Iterable;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.function.Consumer;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.Set;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+import dummy.common.*;
+import dummy.constants.*;
+import dummy.reporting.Reporting;
+import dummy.types.enums.*;
+import dummy.types.model.*;
+import dummy.visitation.AbstractTransformer;
+import java.util.List;
+import java.util.Optional;
+
+public class Verification {
+  /**
+   * Check that the names of the {@code items} are unique.
+   *
+   * <p>The {@code items} are a generic sequence, so the sequences of
+   * the descendants of {@link dummy.types.model.IItem} can be passed without a copy.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean namesAreUnique(
+    List<? extends IItem> items) {
+    Set<String> nameSet = new HashSet<String>();
+    for (var item : items) {
+        if (nameSet.contains(item.getName())) {
+            return false;
+        }
+        nameSet.add(item.getName());
+    }
+    return true;
+  }
+
+  /**
+   * Iterate over a generic sequence in a generator.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean namesAreNonEmpty(
+    List<? extends IItem> items) {
+    return items.stream().allMatch(
+        item -> StringHelpers.len(item.getName()) > 0);
+  }
+
+  /**
+   * Narrow the items of a generic sequence in a generator.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean someSpecialItemHasLevel(
+    List<? extends IItem> items) {
+    return items.stream().anyMatch(
+        item -> item instanceof ISpecialItem
+            && ((ISpecialItem) item).getLevel() > 0);
+  }
+
+  /**
+   * Index a generic sequence, and narrow the item.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean firstIsSpecial(
+    List<? extends IItem> items) {
+    if (items.size() == 0) {
+        return false;
+    }
+    var first = items.get(0);
+    if (first instanceof ISpecialItem) {
+        return ((ISpecialItem) first).getLevel() > 0;
+    }
+    return false;
+  }
+
+  /**
+   * Check that the nicknames of the {@code items} are unique, if specified.
+   *
+   * <p>This mirrors the body of {@code ID_shorts_are_unique} in aas-core-meta V3.2:
+   * a local variable takes an optional property of an item of a generic sequence,
+   * and the loop continues if it is None.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean nicknamesAreUnique(
+    List<? extends IItem> items) {
+    Set<String> nicknameSet = new HashSet<String>();
+    for (var item : items) {
+        var nickname = item.getNickname();
+        if (!nickname.isPresent()) {
+            continue;
+        }
+        if (nicknameSet.contains(nickname.get())) {
+            return false;
+        }
+        nicknameSet.add(nickname.get());
+    }
+    return true;
+  }
+
+  /**
+   * Narrow the loop variable over a generic sequence in a for-loop.
+   *
+   * <p>The loop variable is of the type parameter in Go, so the down-cast needs to
+   * go through {@code any(...)}, and of the template parameter in C++.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean levelsOfSpecialItemsArePositive(
+    List<? extends IItem> items) {
+    for (var item : items) {
+        if (item instanceof ISpecialItem) {
+            if (((ISpecialItem) item).getLevel() <= 0) {
+                return false;
+            }
+        }
+    }
+    return true;
+  }
+
+  /**
+   * Narrow an immutable local variable which holds an item of a generic sequence.
+   *
+   * <p>In contrast to {@link dummy.verification.Verification#firstIsSpecial}, the local variable is annotated, so
+   * it is of the parent class instead of the type parameter. Hence, Go down-casts
+   * it without {@code any(...)}, and C++ binds the item to a constant reference to
+   * the shared pointer of the parent class.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean lastIsSpecial(
+    List<? extends IItem> items) {
+    if (items.size() == 0) {
+        return false;
+    }
+    final IItem last = items.get(items.size() - 1);
+    if (last instanceof ISpecialItem) {
+        return ((ISpecialItem) last).getLevel() > 0;
+    }
+    return false;
+  }
+
+  /**
+   * Mix two generic sequences with an argument which is not generic.
+   *
+   * <p>The names must differ, except for the {@code sharedName}, which may repeat.
+   *
+   * <p>Go declares two type parameters, and C++ two template parameters. The nested
+   * generators iterate over two different generic sequences, so their variables
+   * are of two different type parameters.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   *
+   * <p>The argument {@code otherItems} is declared with the wildcard {@code List<? extends ISomeItem>} instead of the invariant {@code List<ISomeItem>} so that the lists of the descendants of {@link ISomeItem} can be passed without a copy.
+   */
+  public static Boolean namesAreDisjoint(
+    List<? extends IItem> items,
+    List<? extends ISomeItem> otherItems,
+    String sharedName) {
+    return items.stream().allMatch(
+        item -> otherItems.stream().allMatch(
+                otherItem -> !Objects.equals(item.getName(), otherItem.getName())
+                    || Objects.equals(item.getName(), sharedName)));
+  }
+
+  /**
+   * Use the immutable aliases of the generic sequences.
+   *
+   * <p>An immutable alias of the very same type shares the type annotation of
+   * the aliased generic sequence, so it is a generic sequence itself. Go declares
+   * the alias with the type parameter, C++ with the template parameter, while C#
+   * and Java infer its type with {@code var}. The {@code alias_of_alias} aliases an alias,
+   * and the {@code optional_alias} aliases an optional generic sequence.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   *
+   * <p>The argument {@code optionalItems} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean aliasedNamesAreUnique(
+    List<? extends IItem> items,
+    Optional<? extends List<? extends IItem>> optionalItems) {
+    final var alias = items;
+    final var aliasOfAlias = alias;
+    final var optionalAlias = optionalItems;
+    for (var item : alias) {
+        if (item instanceof ISpecialItem) {
+            if (((ISpecialItem) item).getLevel() <= 0) {
+                return false;
+            }
+        }
+    }
+    return (
+        aliasOfAlias.stream().allMatch(
+            item -> StringHelpers.len(item.getName()) > 0)
+    )
+    && namesAreUnique(aliasOfAlias)
+    && optionalNamesAreUnique(optionalAlias)
+    && (
+        (!optionalAlias.isPresent())
+        || namesAreUnique(optionalAlias.orElse(null))
+    );
+  }
+
+  /**
+   * Look up an instance of a descendant in a generic sequence.
+   *
+   * <p>Go compares the instances as {@code any}'s, as the items are of the type parameter,
+   * and C++ converts the member to the shared pointer of {@link dummy.types.model.IItem} so that
+   * the raw pointers are comparable for any template parameter.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean containsSomeItem(
+    ISomeItem someItem,
+    List<? extends IItem> items) {
+    return items.contains(someItem);
+  }
+
+  /**
+   * Look up the items of a generic sequence in another generic sequence.
+   *
+   * <p>The member and the items are of two different type parameters.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   *
+   * <p>The argument {@code otherItems} is declared with the wildcard {@code List<? extends ISomeItem>} instead of the invariant {@code List<ISomeItem>} so that the lists of the descendants of {@link ISomeItem} can be passed without a copy.
+   */
+  public static Boolean itemsOverlap(
+    List<? extends IItem> items,
+    List<? extends ISomeItem> otherItems) {
+    return otherItems.stream().anyMatch(
+        otherItem -> items.contains(otherItem));
+  }
+
+  /**
+   * Look up an instance in a sequence which is not generic.
+   *
+   * <p>The {@link dummy.types.impl.SpecialItem} has no descendants, so the {@code items} are not
+   * a generic sequence, but Go still compares the instances as {@code any}'s.
+   */
+  public static Boolean containsSpecialItem(
+    ISpecialItem specialItem,
+    List<ISpecialItem> items) {
+    return items.contains(specialItem);
+  }
+
+  /**
+   * Pass the local variables on to generic sequences.
+   *
+   * <p>The {@code some_items} is a read-only alias without an annotation, while
+   * the {@code all_some_items} is an immutable local variable declared with
+   * {@code Final[...]}. Both hold the sequences of {@link dummy.types.impl.SomeItem}, and are passed
+   * on to the generic sequences of {@link dummy.types.model.IItem}, required as well as optional.
+   */
+  public static Boolean containerNamesAreUnique(
+    IContainer container) {
+    var someItems = container.getSomeItems();
+    final List<ISomeItem> allSomeItems = container.getSomeItems();
+    return namesAreUnique(someItems)
+    && namesAreUnique(allSomeItems)
+    && optionalNamesAreUnique(Optional.of(allSomeItems));
+  }
+
+  /**
+   * Pass an optional generic sequence on to a generic sequence.
+   *
+   * <p>The argument {@code items} is declared with the wildcard {@code List<? extends IItem>} instead of the invariant {@code List<IItem>} so that the lists of the descendants of {@link IItem} can be passed without a copy.
+   */
+  public static Boolean optionalNamesAreUnique(
+    Optional<? extends List<? extends IItem>> items) {
+    return (!items.isPresent())
+    || namesAreUnique(items.orElse(null));
+  }
+
+  /**
+   * Pass the generic sequences of the descendants on.
+   *
+   * <p>The {@code someItems} are passed on as a required and as an optional
+   * sequence of the parent class, while the {@code specialItems} are passed on
+   * as an optional sequence and, once narrowed, as a required sequence of the parent
+   * class of the parent class.
+   *
+   * <p>The argument {@code someItems} is declared with the wildcard {@code List<? extends ISomeItem>} instead of the invariant {@code List<ISomeItem>} so that the lists of the descendants of {@link ISomeItem} can be passed without a copy.
+   */
+  public static Boolean someNamesAreUnique(
+    List<? extends ISomeItem> someItems,
+    Optional<List<ISpecialItem>> specialItems) {
+    return namesAreUnique(someItems)
+    && optionalNamesAreUnique(Optional.of(someItems))
+    && optionalNamesAreUnique(specialItems)
+    && optionalNamesAreUnique(Optional.empty())
+    && (
+        (!specialItems.isPresent())
+        || namesAreUnique(specialItems.orElse(null))
+    );
+  }
+
+  /**
+   * Check that the levels are positive.
+   *
+   * <p>The {@link dummy.types.impl.SpecialItem} has no descendants, so the {@code items} are not
+   * a generic sequence.
+   */
+  public static Boolean levelsArePositive(
+    List<ISpecialItem> items) {
+    return items.stream().allMatch(
+        item -> item.getLevel() > 0);
+  }
+
+  /**
+   * Hash allowed enum values for efficient validation of enums.
+   */
+  private static class _EnumValueSet {
+
+  }
+
+  private static final _Transformer transformer = new _Transformer();
+
+  private static class _Transformer extends AbstractTransformer<Stream<Reporting.Error>> {
+    @Override
+    public Stream<Reporting.Error> transformSomeItem(
+      ISomeItem that) {
+      Stream<Reporting.Error> errorStream = Stream.empty();
+
+      // No verification has been defined for SomeItem.
+
+      return errorStream;
+    }
+
+    @Override
+    public Stream<Reporting.Error> transformSpecialItem(
+      ISpecialItem that) {
+      Stream<Reporting.Error> errorStream = Stream.empty();
+
+      // No verification has been defined for SpecialItem.
+
+      return errorStream;
+    }
+
+    @Override
+    public Stream<Reporting.Error> transformContainer(
+      IContainer that) {
+      Stream<Reporting.Error> errorStream = Stream.empty();
+
+      if (!(
+        !(that.getSpecialItems().isPresent())
+        || (
+            that.getSpecialItems().get().stream().allMatch(
+                specialItem -> containsSpecialItem(specialItem, that.getSpecialItems().orElse(null)))
+        ))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Each special item must be among the special items.")));
+      }
+
+      if (!(
+        that.getSomeItems().size() == 0
+        || itemsOverlap(that.getItems(), that.getSomeItems()))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "If there are some items, they must overlap with the items.")));
+      }
+
+      if (!(
+        that.getSomeItems().stream().allMatch(
+            someItem -> containsSomeItem(someItem, that.getItems())))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Some items must be among the items.")));
+      }
+
+      if (!(
+        aliasedNamesAreUnique(that.getSomeItems(), that.getSpecialItems()))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of some items and of special items must be unique " +
+            "through aliases.")));
+      }
+
+      if (!(
+        namesAreDisjoint(that.getItems(), that.getSomeItems(), "x"))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of the items and of some items must be disjoint.")));
+      }
+
+      if (!(
+        !someSpecialItemHasLevel(that.getItems())
+        || lastIsSpecial(that.getItems()))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "If there is a special item with level, the last item must " +
+            "be special.")));
+      }
+
+      if (!levelsOfSpecialItemsArePositive(that.getItems())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Levels of the special items among the items must be " +
+            "positive.")));
+      }
+
+      if (!nicknamesAreUnique(that.getSomeItems())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Nicknames of some items must be unique.")));
+      }
+
+      if (!(
+        that.countItems(that.getItems()) == that.getItems().size())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Count of the items must match the number of the items.")));
+      }
+
+      if (!optionalNamesAreUnique(that.getSpecialItems())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of the special items must be unique.")));
+      }
+
+      if (!(
+        !(that.getSpecialItems().isPresent())
+        || firstIsSpecial(that.getSpecialItems().orElse(null)))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "The first special item must be special.")));
+      }
+
+      if (!(
+        !(that.getSpecialItems().isPresent())
+        || levelsArePositive(that.getSpecialItems().orElse(null)))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Levels of the special items must be positive.")));
+      }
+
+      if (!(
+        !someSpecialItemHasLevel(that.getItems())
+        || firstIsSpecial(that.getItems()))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "If there is a special item with level, the first item must " +
+            "be special.")));
+      }
+
+      if (!namesAreNonEmpty(that.getSomeItems())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of some items must be non-empty.")));
+      }
+
+      if (!(
+        someNamesAreUnique(that.getSomeItems(), that.getSpecialItems()))) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of some items and of special items must be unique.")));
+      }
+
+      if (!namesAreUnique(that.getItems())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of the items must be unique.")));
+      }
+
+      errorStream = Stream.<Reporting.Error>concat(errorStream,
+        Stream.of(that.getItems())
+          .flatMap(Verification::verifyListOf_IItem)
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.NameSegment("items"));
+              return error;
+            }));
+
+      errorStream = Stream.<Reporting.Error>concat(errorStream,
+        Stream.of(that.getSomeItems())
+          .flatMap(Verification::verifyListOf_ISomeItem)
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.NameSegment("someItems"));
+              return error;
+            }));
+
+      if (that.getSpecialItems().isPresent()) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(that.getSpecialItems().get())
+            .flatMap(Verification::verifyListOf_ISpecialItem)
+              .map(error -> {
+                error.prependSegment(
+                  new Reporting.NameSegment("specialItems"));
+                return error;
+              }));
+      }
+
+      return errorStream;
+    }
+
+    @Override
+    public Stream<Reporting.Error> transformWrapper(
+      IWrapper that) {
+      Stream<Reporting.Error> errorStream = Stream.empty();
+
+      if (!containerNamesAreUnique(that.getContainer())) {
+        errorStream = Stream.<Reporting.Error>concat(errorStream,
+          Stream.of(new Reporting.Error(
+            "Invariant violated:\n" +
+            "Names of some items of the container must be unique.")));
+      }
+
+      errorStream = Stream.<Reporting.Error>concat(errorStream,
+        Stream.of(that.getContainer())
+          .flatMap(Verification::verifyToErrorStream)
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.NameSegment("container"));
+              return error;
+            }));
+
+      return errorStream;
+    }
+  }
+
+  public static Stream<Reporting.Error> verifyToErrorStream(IClass that) {
+    return transformer.transform(that);
+  }
+
+  private static class _ValidationErrorIterable implements Iterable<Reporting.Error> {
+    private final IClass element;
+
+    public _ValidationErrorIterable(IClass element) {
+      this.element = element;
+  }
+
+    @Override
+    public Iterator<Reporting.Error> iterator() {
+      Stream<Reporting.Error> stream = stream();
+
+      return stream.iterator();
+    }
+
+    @Override
+    public void forEach(Consumer<? super Reporting.Error> action) {
+      Stream<Reporting.Error> stream = stream();
+
+      stream.forEach(action);
+    }
+
+    @Override
+    public Spliterator<Reporting.Error> spliterator() {
+      Stream<Reporting.Error> stream = stream();
+
+      return stream.spliterator();
+    }
+
+    private Stream<Reporting.Error> stream() {
+      return Verification.verifyToErrorStream(element);
+    }
+  }
+
+  /**
+   * Verify the constraints of {@code that} recursively.
+   *
+   * @param that The instance of the meta-model to be verified
+   */
+  public static Iterable<Reporting.Error> verify(IClass that) {
+    return new _ValidationErrorIterable(that);
+  }
+
+  /**
+   * Verify the items of {@code that} recursively.
+   */
+  private static Stream<Reporting.Error> verifyListOf_IItem(
+    List<IItem> that) {
+    return Verification.zip(
+      IntStream.iterate(0, i -> i + 1).boxed(),
+      that.stream())
+        .flatMap(itemTuple ->
+          Verification.verifyToErrorStream(itemTuple.getSecond())
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.IndexSegment(itemTuple.getFirst()));
+              return error;
+            }));
+  }
+
+  /**
+   * Verify the items of {@code that} recursively.
+   */
+  private static Stream<Reporting.Error> verifyListOf_ISomeItem(
+    List<ISomeItem> that) {
+    return Verification.zip(
+      IntStream.iterate(0, i -> i + 1).boxed(),
+      that.stream())
+        .flatMap(itemTuple ->
+          Verification.verifyToErrorStream(itemTuple.getSecond())
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.IndexSegment(itemTuple.getFirst()));
+              return error;
+            }));
+  }
+
+  /**
+   * Verify the items of {@code that} recursively.
+   */
+  private static Stream<Reporting.Error> verifyListOf_ISpecialItem(
+    List<ISpecialItem> that) {
+    return Verification.zip(
+      IntStream.iterate(0, i -> i + 1).boxed(),
+      that.stream())
+        .flatMap(itemTuple ->
+          Verification.verifyToErrorStream(itemTuple.getSecond())
+            .map(error -> {
+              error.prependSegment(
+                new Reporting.IndexSegment(itemTuple.getFirst()));
+              return error;
+            }));
+  }
+
+  private static class _Pair<A, B> {
+    private final A first;
+    private final B second;
+
+    public _Pair(A first, B second) {
+      this.first = first;
+      this.second = second;
+    }
+
+    public A getFirst() {
+      return first;
+    }
+
+    public B getSecond() {
+      return second;
+    }
+  }
+
+  // Java 8 doesn't provide a split operation out of the box, so we have to ship our own.
+  // Adapted from: https://stackoverflow.com/a/23529010
+  private static <A, B> Stream<_Pair<A, B>> zip(
+    Stream<? extends A> a,
+    Stream<? extends B> b) {
+    Spliterator<? extends A> aSplit = Objects.requireNonNull(a).spliterator();
+    Spliterator<? extends B> bSplit = Objects.requireNonNull(b).spliterator();
+
+    int characteristics = aSplit.characteristics() & bSplit.characteristics() &
+      ~(Spliterator.DISTINCT | Spliterator.SORTED);
+
+    long zipSize = ((characteristics & Spliterator.SIZED) != 0)
+      ? Math.min(aSplit.getExactSizeIfKnown(), bSplit.getExactSizeIfKnown())
+      : -1;
+
+    Iterator<A> aIter = Spliterators.iterator(aSplit);
+    Iterator<B> bIter = Spliterators.iterator(bSplit);
+    Iterator<_Pair<A, B>> cIter = new Iterator<_Pair<A, B>>() {
+      @Override
+      public boolean hasNext() {
+        return aIter.hasNext() && bIter.hasNext();
+      }
+
+      @Override
+      public _Pair<A, B> next() {
+        return new _Pair<>(aIter.next(), bIter.next());
+      }
+    };
+
+    Spliterator<_Pair<A, B>> split = Spliterators.spliterator(cIter, zipSize, characteristics);
+    return StreamSupport.stream(split, false);
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformer.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformer.java
new file mode 100644
index 000000000..6d16e57b7
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformer.java
@@ -0,0 +1,44 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+import dummy.visitation.ITransformer;
+
+/**
+ * Perform double-dispatch to transform recursively
+ * the instances into something else.
+ *
+ * @param <T> type of the transformation result
+ */
+public abstract class AbstractTransformer<T> implements ITransformer<T>
+{
+  public T transform(IClass that)
+  {
+    return that.transform(this);
+  }
+
+  public abstract T transformSomeItem(
+    ISomeItem that
+  );
+
+  public abstract T transformSpecialItem(
+    ISpecialItem that
+  );
+
+  public abstract T transformContainer(
+    IContainer that
+  );
+
+  public abstract T transformWrapper(
+    IWrapper that
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformerWithContext.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformerWithContext.java
new file mode 100644
index 000000000..2ac6b3cbe
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractTransformerWithContext.java
@@ -0,0 +1,54 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+import dummy.visitation.ITransformerWithContext;
+
+/**
+ * Perform double-dispatch to transform recursively
+ * the instances into something else.
+ *
+ * <p>When you use the transformer, please always call the main dispatching method
+ * {@link AbstractTransformerWithContext#transform}. You should most probably never call the {@code transform}
+ * methods directly. They are only made public so that model classes can access them.
+ *
+ * @param <ContextT> structure of the context
+ * @param <T> type of the transformation result
+ */
+public abstract class AbstractTransformerWithContext<ContextT, T>
+  implements ITransformerWithContext<ContextT, T>
+{
+  public T transform(IClass that, ContextT context)
+  {
+    return that.transform(this, context);
+  }
+
+  public abstract T transformSomeItem(
+    ISomeItem that,
+    ContextT context
+  );
+
+  public abstract T transformSpecialItem(
+    ISpecialItem that,
+    ContextT context
+  );
+
+  public abstract T transformContainer(
+    IContainer that,
+    ContextT context
+  );
+
+  public abstract T transformWrapper(
+    IWrapper that,
+    ContextT context
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitor.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitor.java
new file mode 100644
index 000000000..4ed03c8d3
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitor.java
@@ -0,0 +1,37 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+import dummy.visitation.IVisitor;
+
+/**
+ * Perform double-dispatch to visit the concrete instances.
+ */
+public abstract class AbstractVisitor implements IVisitor
+{
+  public void visit(IClass that)
+  {
+    that.accept(this);
+  }
+  public abstract void visitSomeItem(
+    ISomeItem that
+  );
+  public abstract void visitSpecialItem(
+    ISpecialItem that
+  );
+  public abstract void visitContainer(
+    IContainer that
+  );
+  public abstract void visitWrapper(
+    IWrapper that
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitorWithContext.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitorWithContext.java
new file mode 100644
index 000000000..42ec64ec4
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/AbstractVisitorWithContext.java
@@ -0,0 +1,45 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+import dummy.visitation.IVisitorWithContext;
+
+/**
+ * Perform double-dispatch to visit the concrete instances
+ * with context.
+ *
+ * @param <ContextT> structure of the context
+ */
+public abstract class AbstractVisitorWithContext<ContextT>
+  implements IVisitorWithContext<ContextT>
+{
+  public void visit(IClass that, ContextT context)
+  {
+    that.accept(this, context);
+  }
+  public abstract void visitSomeItem(
+    ISomeItem that,
+    ContextT context
+  );
+  public abstract void visitSpecialItem(
+    ISpecialItem that,
+    ContextT context
+  );
+  public abstract void visitContainer(
+    IContainer that,
+    ContextT context
+  );
+  public abstract void visitWrapper(
+    IWrapper that,
+    ContextT context
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformer.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformer.java
new file mode 100644
index 000000000..302d81071
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformer.java
@@ -0,0 +1,39 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+
+/**
+ * Define the interface for a transformer which transforms recursively
+ * the instances into something else.
+ *
+ * <p>When you use the transformer, please always call the main dispatching method
+ * {@link ITransformer#transform}. You should most probably never call the {@code transform}
+ * methods directly. They are only made public so that model classes can access them.
+ *
+ * @param <T> type of the transformation result
+ */
+public interface ITransformer<T> {
+  T transform(IClass that);
+  T transformSomeItem(
+    ISomeItem that
+  );
+  T transformSpecialItem(
+    ISpecialItem that
+  );
+  T transformContainer(
+    IContainer that
+  );
+  T transformWrapper(
+    IWrapper that
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformerWithContext.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformerWithContext.java
new file mode 100644
index 000000000..7c81d9d3f
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/ITransformerWithContext.java
@@ -0,0 +1,44 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+
+/**
+ * Define the interface for a transformer which recursively transforms
+ * the instances into something else while the context is passed along.
+ *
+ * <p>When you use the transformer, please always call the main dispatching method
+ * {@link ITransformerWithContext#transform}. You should most probably never call the {@code transform}
+ * methods directly. They are only made public so that model classes can access them.
+ *
+ * @param <ContextT> structure of the context
+ * @param <T> type of the transformation result
+ */
+public interface ITransformerWithContext<ContextT, T> {
+  T transform(IClass that, ContextT context);
+  T transformSomeItem(
+    ISomeItem that,
+    ContextT context
+  );
+  T transformSpecialItem(
+    ISpecialItem that,
+    ContextT context
+  );
+  T transformContainer(
+    IContainer that,
+    ContextT context
+  );
+  T transformWrapper(
+    IWrapper that,
+    ContextT context
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitor.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitor.java
new file mode 100644
index 000000000..bb180070d
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitor.java
@@ -0,0 +1,37 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+
+/**
+ * Define the interface for a visitor which visits the instances of the model.
+ *
+ * <p>When you use the visitor, please always call the main dispatching method
+ * {@link IVisitor#visit}. You should most probably never call the {@code visit*}
+ * methods directly. They are only made public so that model classes can access them.
+ */
+public interface IVisitor
+{
+  void visit(IClass that);
+  void visitSomeItem(
+    ISomeItem that
+  );
+  void visitSpecialItem(
+    ISpecialItem that
+  );
+  void visitContainer(
+    IContainer that
+  );
+  void visitWrapper(
+    IWrapper that
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitorWithContext.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitorWithContext.java
new file mode 100644
index 000000000..e8a3d10d7
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/IVisitorWithContext.java
@@ -0,0 +1,43 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+
+/**
+ * Define the interface for a visitor which visits the instances of the model.
+ *
+ * <p>When you use the visitor, please always call the main dispatching method
+ * {@link IVisitorWithContext#visit}. You should most probably never call the {@code visit}
+ * methods directly. They are only made public so that model classes can access them.
+ *
+ * @param <ContextT> structure of the context
+ */
+public interface IVisitorWithContext<ContextT>
+{
+  void visit(IClass that, ContextT context);
+  void visitSomeItem(
+    ISomeItem that,
+    ContextT context
+  );
+  void visitSpecialItem(
+    ISpecialItem that,
+    ContextT context
+  );
+  void visitContainer(
+    IContainer that,
+    ContextT context
+  );
+  void visitWrapper(
+    IWrapper that,
+    ContextT context
+  );
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/VisitorThrough.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/VisitorThrough.java
new file mode 100644
index 000000000..ec2b7d3e7
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/visitation/VisitorThrough.java
@@ -0,0 +1,63 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.visitation;
+
+import dummy.types.model.*;
+import dummy.visitation.IVisitor;
+
+/**
+ * Just descend through the instances without any action.
+ *
+ * <p>This class is meaningless for itself. However, it is a good base if you
+ * want to descend through instances and apply actions only on a subset of
+ * classes.
+ */
+public class VisitorThrough implements IVisitor {
+  public void visit(IClass that) {
+    that.accept(this);
+  }
+
+  public void visitSomeItem(
+    ISomeItem that
+  ) {
+    // Just descend through, do nothing with {@code that}
+    for (IClass something : that.descendOnce()) {
+      visit(something);
+    }
+  }
+
+  public void visitSpecialItem(
+    ISpecialItem that
+  ) {
+    // Just descend through, do nothing with {@code that}
+    for (IClass something : that.descendOnce()) {
+      visit(something);
+    }
+  }
+
+  public void visitContainer(
+    IContainer that
+  ) {
+    // Just descend through, do nothing with {@code that}
+    for (IClass something : that.descendOnce()) {
+      visit(something);
+    }
+  }
+
+  public void visitWrapper(
+    IWrapper that
+  ) {
+    // Just descend through, do nothing with {@code that}
+    for (IClass something : that.descendOnce()) {
+      visit(something);
+    }
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlcommon/XmlCommon.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlcommon/XmlCommon.java
new file mode 100644
index 000000000..4bbabc16b
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlcommon/XmlCommon.java
@@ -0,0 +1,586 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.xmlcommon;
+
+import javax.xml.stream.events.XMLEvent;
+import javax.xml.stream.XMLEventReader;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamWriter;
+import java.util.Optional;
+import java.util.regex.Pattern;
+import dummy.reporting.Reporting;
+
+/**
+ * Provide the XML primitives shared by the de/serialization.
+ *
+ * <p>The xmlization reads and writes the elements of our own classes, and
+ * the XML-RPC de/serialization the elements within a JSON-able value. The
+ * skipping of what carries no information, the check of the XML namespace
+ * and the framing of an element are the same for both, and live here.
+ *
+ * <p>Java has no visibility which would show a class to a sibling package
+ * and hide it from the user of the library, so everything here is public.
+ */
+public final class XmlCommon {
+    private XmlCommon() {
+        // NOTE (mristin):
+        // The XML primitives are stateless, so there is nothing to
+        // instantiate.
+    }
+
+    /**
+     * The XML namespace in which all the elements of a document reside.
+     *
+     * <p>The elements of the XML-RPC subset, over which a JSON-able value is
+     * de/serialized, are the one exception: they reside in no namespace at all.
+     */
+    public static final String NAMESPACE =
+        "https://dummy.com";
+
+    /**
+     * Read the content of an element which has already been opened.
+     *
+     * <p>{isEmpty} tells whether that element was self-closing.
+     */
+    @FunctionalInterface
+    public interface ContentReader<T> {
+        Reporting.Result<? extends T> read(XMLEventReader reader, boolean isEmpty);
+    }
+
+    /**
+     * Read a whole element, opening and closing it.
+     */
+    @FunctionalInterface
+    public interface ElementReader<T> {
+        Reporting.Result<? extends T> read(XMLEventReader reader);
+    }
+
+    /**
+     * Write {@code that} where {@code writer} already is.
+     *
+     * <p>Every value is written through this one shape, so that the writing
+     * composes: {@link #writeElement} frames it in a start and an end tag, and
+     * a class's own {@code write...AsSequence} already is one.
+     *
+     * <p>There is deliberately no second shape for a whole element, as there is
+     * on the reading side. An element differs from a content only in what it
+     * writes, never in its shape; the reading needs the distinction because
+     * a content reader has to be told whether its element was self-closing, and
+     * a writer has nothing to be told.
+     *
+     * <p>Use sites take a {@code ContentWriter<? super T>} -- Java's spelling
+     * of the contravariance -- so that the single writer of an {@link IClass}
+     * serves wherever the writer of a more specific interface is expected.
+     */
+    @FunctionalInterface
+    public interface ContentWriter<T> {
+        void write(T that, XMLStreamWriter writer) throws XMLStreamException;
+    }
+
+    /**
+     * Match a run of the four characters which XML calls whitespace.
+     */
+    public static final Pattern WHITESPACE_RUN = Pattern.compile("[ \t\n\r]+");
+
+    /**
+     * Read the text of the element which the caller has opened.
+     *
+     * <p>The comments in between are skipped, and the pieces of the text are
+     * joined, as a reader is free to split it.
+     */
+    public static String readContentAsString(
+        XMLEventReader reader) throws XMLStreamException {
+        final StringBuilder content = new StringBuilder();
+
+        while (reader.peek().isCharacters()
+            || reader.peek().getEventType() == XMLStreamConstants.COMMENT) {
+            if (reader.peek().isCharacters()) {
+                content.append(reader.peek().asCharacters().getData());
+            }
+            reader.nextEvent();
+        }
+
+        return content.toString();
+    }
+
+    /**
+     * Normalize {@code text} the way {@code whiteSpace="collapse"}
+     * prescribes.
+     *
+     * <p>Every atomic XSD type except a string fixes {@code whiteSpace} to
+     * {@code collapse}, and a schema author can not change it. A tab, a line
+     * feed and a carriage return each become a space, a run of spaces becomes
+     * one space, and the leading and trailing spaces go.
+     *
+     * <p>See: https://www.w3.org/TR/xmlschema-2/#rf-whiteSpace
+     */
+    public static String collapseWhitespace(String text) {
+        return WHITESPACE_RUN.matcher(text).replaceAll(" ").trim();
+    }
+
+    /**
+     * Represent a critical error during the deserialization.
+     */
+    @SuppressWarnings("serial")
+    public static class DeserializeException extends RuntimeException {
+        private final String path;
+        private final String reason;
+
+        public DeserializeException(String path, String reason) {
+            super(reason + " at: " + ("".equals(path) ? "the beginning" : path));
+            this.path = path;
+            this.reason = reason;
+        }
+
+        public Optional<String> getPath() {
+            return Optional.ofNullable(path);
+        }
+
+        public Optional<String> getReason() {
+            return Optional.ofNullable(reason);
+        }
+    }
+
+    /**
+     * Represent a critical error during the serialization.
+     */
+    @SuppressWarnings("serial")
+    public static class SerializeException extends RuntimeException {
+        private final String path;
+        private final String reason;
+
+        public SerializeException(String path, String reason) {
+            super(reason + " at: " + ("".equals(path) ? "the beginning" : path));
+            this.path = path;
+            this.reason = reason;
+        }
+
+        public Optional<String> getPath() {
+            return Optional.ofNullable(path);
+        }
+
+        public Optional<String> getReason() {
+            return Optional.ofNullable(reason);
+        }
+    }
+
+    /**
+     * Signal a failure of the serialization, carrying the path to the culprit.
+     *
+     * <p>The path is built as the stack unwinds -- every container prepends
+     * the one segment it knows, the property its name and the list the index
+     * of the item -- which is why this can not be the exception which
+     * the caller sees already: that one renders its message in its
+     * constructor, so its path has to be complete by then. The enclosing
+     * serializer renders and converts.
+     *
+     * <p>This is thrown across a package boundary, from the XML-RPC writers
+     * into the xmlization's, so it is public.
+     */
+    @SuppressWarnings("serial")
+    public static class SerializeFailure extends RuntimeException {
+        private final Reporting.Error error;
+
+        public SerializeFailure(Reporting.Error error) {
+            super(error.getCause());
+            this.error = error;
+        }
+
+        public Reporting.Error getError() {
+            return error;
+        }
+    }
+
+    public static XMLEvent currentEvent(XMLEventReader reader) {
+        try {
+            return reader.peek();
+        } catch (XMLStreamException xmlStreamException) {
+            throw new DeserializeException("",
+                "Failed in method peek because of: " +
+                xmlStreamException.getMessage());
+        }
+    }
+
+    public static String getEventTypeAsString(XMLEvent event) {
+        switch (event.getEventType()) {
+            case XMLStreamConstants.START_ELEMENT:
+                return "Start-Element";
+            case XMLStreamConstants.END_ELEMENT:
+                return "End-Element";
+            case XMLStreamConstants.PROCESSING_INSTRUCTION:
+                return "Processing-Instruction";
+            case XMLStreamConstants.CHARACTERS:
+                return "Characters";
+            case XMLStreamConstants.COMMENT:
+                return "Comment";
+            case XMLStreamConstants.SPACE:
+                return "Space";
+            case XMLStreamConstants.START_DOCUMENT:
+                return "Start-Document";
+            case XMLStreamConstants.END_DOCUMENT:
+                return "End-Document";
+            case XMLStreamConstants.ENTITY_REFERENCE:
+                return "Entity-Reference";
+            case XMLStreamConstants.ATTRIBUTE:
+                return "Attribute";
+            case XMLStreamConstants.NOTATION_DECLARATION:
+                return "Notation-Declaration";
+            default:
+                return "Unknown-Type";
+        }
+    }
+
+    public static void skipWhitespaceAndComments(XMLEventReader reader) {
+        while (whiteSpaceOrComment(reader)) {
+            reader.next();
+        }
+    }
+
+    public static boolean whiteSpaceOrComment(XMLEventReader reader) {
+        final XMLEvent currentEvent = currentEvent(reader);
+        final boolean isComment = (currentEvent != null &&
+            currentEvent.getEventType() == XMLStreamConstants.COMMENT);
+        final boolean isWhiteSpace = (currentEvent != null &&
+            currentEvent.getEventType() == XMLStreamConstants.CHARACTERS &&
+            currentEvent.asCharacters().isWhiteSpace());
+        return isComment || isWhiteSpace;
+    }
+
+    public static boolean isEmptyElement(XMLEventReader reader) {
+        // Skip the element node and go to the content
+        try {
+            reader.nextEvent();
+        } catch (XMLStreamException xmlStreamException) {
+            throw new DeserializeException("",
+                "Failed in method isEmptyElement because of: " +
+                xmlStreamException.getMessage());
+        }
+        return currentEvent(reader).isEndElement();
+    }
+
+    /**
+     * Write {@code that.toString()} as XML content.
+     *
+     * <p>This is the {@link ContentWriter} of every {@code boolean}/
+     * {@code long}/{@code double}/{@code String}-typed value, be it
+     * a property, a list item or a tuple item.
+     */
+    public static <T> void writeStringifiedContent(
+        T that,
+        XMLStreamWriter writer) throws XMLStreamException {
+        writer.writeCharacters(that.toString());
+    }
+
+    /**
+     * Write {@code that} as XML content in the lexical form of
+     * {@code xs:double}.
+     *
+     * <p>This is the {@link ContentWriter} of every {@code double}-typed
+     * value, be it a property, a list item or a tuple item. A double can not
+     * share {@link #writeStringifiedContent} with the other primitives:
+     * {@code Double.toString} renders an infinity as {@code Infinity}, where
+     * {@code xs:double} spells it {@code INF}. Only the two infinities differ
+     * -- {@code NaN} is spelled the same way in both, and a finite number is
+     * rendered by {@code Double.toString} in a form which {@code xs:double}
+     * accepts.
+     *
+     * <p>See: https://www.w3.org/TR/xmlschema-2/#double
+     */
+    public static void writeDoubleContent(
+        Double that,
+        XMLStreamWriter writer) throws XMLStreamException {
+        final String text;
+        if (that.isInfinite()) {
+            text = (that > 0) ? "INF" : "-INF";
+        } else {
+            text = that.toString();
+        }
+
+        writer.writeCharacters(text);
+    }
+
+    /**
+     * Describe {@code ns} for an error message.
+     */
+    private static String describeNamespace(String ns) {
+        return ns.isEmpty() ? "no namespace" : "the namespace " + ns;
+    }
+
+    private static boolean invalidNameSpace(XMLEvent event, String ns) {
+        if (event.isStartElement()) {
+            return !ns.equals(event.asStartElement().getName().getNamespaceURI());
+        } else {
+            return !ns.equals(event.asEndElement().getName().getNamespaceURI());
+        }
+    }
+
+    /**
+     * Check the namespace and extract the element's name.
+     */
+    private static Reporting.Result<String> tryElementName(
+        XMLEventReader reader, String ns) {
+        final XMLEvent currentEvent = currentEvent(reader);
+        final boolean precondition = currentEvent.isStartElement() || currentEvent.isEndElement();
+        if (!precondition) {
+            throw new IllegalStateException("Expected to be at a start or an end element "
+                    + "but got: " + getEventTypeAsString(currentEvent));
+        }
+
+        if (invalidNameSpace(currentEvent, ns)) {
+            final String namespace = currentEvent.isStartElement()
+                    ? currentEvent.asStartElement().getName().getNamespaceURI()
+                    : currentEvent.asEndElement().getName().getNamespaceURI();
+            final Reporting.Error error = new Reporting.Error(
+                    "Expected an element within " + describeNamespace(ns) +
+                    ", but got an element within " + describeNamespace(namespace));
+            return Reporting.Result.failure(error);
+        }
+        return Reporting.Result.success(currentEvent.isStartElement()
+                ? currentEvent.asStartElement().getName().getLocalPart()
+                : currentEvent.asEndElement().getName().getLocalPart());
+    }
+
+    /**
+     * Look up the name of the element which {@code reader} is positioned at.
+     *
+     * <p>This is the single primitive answering "we are at an element, and this is
+     * its name": {@link #readNamedElement} checks that name against the one its
+     * container supplied, a dispatcher switches on it, and a property loop uses it
+     * to select the property. Nothing is consumed, which is what lets a dispatcher
+     * hand the whole element on to the reader it selected.
+     */
+    private static Reporting.Result<String> peekElementNameInNamespace(
+        XMLEventReader reader, String ns) {
+        skipWhitespaceAndComments(reader);
+
+        final XMLEvent currentEvent = currentEvent(reader);
+        if (currentEvent.isEndDocument()) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML element, but reached the end-of-file"));
+        }
+
+        if (!currentEvent.isStartElement()) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML element, but got the node of type " +
+                getEventTypeAsString(currentEvent) + " with the value " + currentEvent));
+        }
+
+        return tryElementName(reader, ns);
+    }
+
+    /**
+     * Consume the end tag concluding the element called {@code elementName}.
+     */
+    private static Reporting.Result<XMLEvent> consumeEndElementInNamespace(
+        XMLEventReader reader, String elementName, String ns) {
+        skipWhitespaceAndComments(reader);
+
+        final XMLEvent currentEvent = currentEvent(reader);
+        if (currentEvent.isEndDocument()) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML end element to conclude the element " + elementName +
+                ", but got the end-of-file"));
+        }
+
+        if (!currentEvent.isEndElement()) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML end element to conclude the element " + elementName +
+                ", but got the node of type " + getEventTypeAsString(currentEvent) +
+                " with the value " + currentEvent));
+        }
+
+        final Reporting.Result<String> tryEndElementName = tryElementName(reader, ns);
+        if (tryEndElementName.isError()) {
+            return tryEndElementName.castTo(XMLEvent.class);
+        }
+
+        if (!elementName.equals(tryEndElementName.getResult())) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML end element to conclude the element " + elementName +
+                ", but got the end element with the name " + tryEndElementName.getResult()));
+        }
+
+        try {
+            return Reporting.Result.success(reader.nextEvent());
+        } catch (XMLStreamException xmlStreamException) {
+            throw new DeserializeException("",
+                "Failed in method consumeEndElement because of: " +
+                xmlStreamException.getMessage());
+        }
+    }
+
+    /**
+     * Read a whole element which is expected to be called {@code name} and to
+     * reside in {@code ns}, and read its content with {@code readContent}.
+     *
+     * <p>The name is data, not a type: an instance reads the XML name of its own
+     * class, a list item reads {@code "v"} and a tuple item reads {@code "v1"},
+     * {@code "v2"}, ... by position. One framer therefore serves them all.
+     */
+    private static <T> Reporting.Result<? extends T> readNamedElementInNamespace(
+        XMLEventReader reader, String name, String ns,
+        ContentReader<T> readContent) {
+        final Reporting.Result<String> tryElementName = peekElementNameInNamespace(reader, ns);
+        if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+        }
+
+        if (!name.equals(tryElementName.getResult())) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML element " + name + ", but got an XML element " +
+                tryElementName.getResult()));
+        }
+
+        final boolean isEmpty = isEmptyElement(reader);
+
+        final Reporting.Result<? extends T> result =
+            readContent.read(reader, isEmpty);
+        if (result.isError()) {
+            return result;
+        }
+
+        final Reporting.Result<XMLEvent> endResult =
+            consumeEndElementInNamespace(reader, name, ns);
+        if (endResult.isError()) {
+            return Reporting.Result.failure(endResult.getError());
+        }
+
+        return result;
+    }
+
+    /**
+     * Look up the name of the element in {@link #NAMESPACE} which
+     * {@code reader} is positioned at.
+     *
+     * <p>This is the single primitive answering "we are at an element, and this is
+     * its name": {@link #readNamedElement} checks that name against the one its
+     * container supplied, a dispatcher switches on it, and a property loop uses it
+     * to select the property. Nothing is consumed, which is what lets a dispatcher
+     * hand the whole element on to the reader it selected.
+     */
+    public static Reporting.Result<String> peekElementName(XMLEventReader reader) {
+        return peekElementNameInNamespace(reader, NAMESPACE);
+    }
+
+    /**
+     * Consume the end tag concluding the element called {@code elementName} in
+     * {@link #NAMESPACE}.
+     */
+    public static Reporting.Result<XMLEvent> consumeEndElement(
+        XMLEventReader reader, String elementName) {
+        return consumeEndElementInNamespace(reader, elementName, NAMESPACE);
+    }
+
+    /**
+     * Read a whole element in {@link #NAMESPACE} which is expected to be called
+     * {@code name}, and read its content with {@code readContent}.
+     */
+    public static <T> Reporting.Result<? extends T> readNamedElement(
+        XMLEventReader reader, String name, ContentReader<T> readContent) {
+        return readNamedElementInNamespace(reader, name, NAMESPACE, readContent);
+    }
+
+    /**
+     * Read a self-describing element as the content of the property element which
+     * {@code reader} is already positioned inside.
+     *
+     * <p>This looks like a needless layer over {@code read...FromElement}: the
+     * reader sits at the very same position in both cases, just before a start
+     * element, whether that element is the only child of a property element or
+     * the next item of a list. The layer exists for the error path alone.
+     *
+     * <p>A property wraps its instance in an element of its own, so the failing
+     * node is one step deeper than the property and the discriminator's name has
+     * to be prepended: {@code value/property/idShort}. A list item is not
+     * wrapped -- the item element *is* the indexed child -- so prepending the name
+     * there would give {@code annotations/*[1]/property/idShort}, which walks one
+     * level past the element {@code *[1]} already selects and resolves to
+     * nothing.
+     *
+     * <p>The two callers therefore need different segments, which is why the name
+     * can not be prepended inside {@code read...FromElement}. Unifying them would
+     * take a segment carrying a name *and* a position
+     * ({@code annotations/property[1]}), and that is a change to
+     * {@link Reporting}, which the verification and the JSON de-serialization
+     * share.
+     */
+    public static <T> Reporting.Result<? extends T> readNestedElement(
+        XMLEventReader reader, boolean isEmpty, ElementReader<T> readInner) {
+        if (isEmpty) {
+            return Reporting.Result.failure(new Reporting.Error(
+                "Expected an XML element representing an instance, " +
+                "but encountered a self-closing element"));
+        }
+
+        final Reporting.Result<String> tryElementName = peekElementName(reader);
+        if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+        }
+
+        final Reporting.Result<? extends T> result = readInner.read(reader);
+        if (result.isError()) {
+            result.getError()
+                .prependSegment(
+                    new Reporting.NameSegment(
+                        tryElementName.getResult()));
+        }
+
+        return result;
+    }
+
+    /**
+     * Write {@code that} as an XML element named {@code name}, its content
+     * written by {@code writeContent}.
+     *
+     * <p>An element is nothing but a start and an end tag around a content, so
+     * there is no writer per property kind: only the content writer differs,
+     * and the type of the value alone decides which one it is.
+     *
+     * <p>{@code withNamespace} declares {@link #NAMESPACE} on the element,
+     * which only the outermost element does.
+     */
+    public static <T> void writeElement(
+        String name,
+        T that,
+        XMLStreamWriter writer,
+        boolean withNamespace,
+        ContentWriter<? super T> writeContent) {
+        try {
+            writer.writeStartElement(name);
+            if (withNamespace) {
+                writer.writeNamespace("xmlns", NAMESPACE);
+            }
+            writeContent.write(that, writer);
+            writer.writeEndElement();
+        } catch (XMLStreamException exception) {
+            throw new SerializeFailure(
+                new Reporting.Error(exception.getMessage()));
+        }
+    }
+
+    /**
+     * Write {@code that} as an XML element named {@code name} nested in
+     * another element, so that the XML namespace is not re-declared.
+     *
+     * <p>This is what an item of a list or of a tuple is written with. It
+     * contributes no segment to the error path: its container has already
+     * contributed the item's index, and the index selects this very element
+     * (see {@link #writeListOf} in the generated writers).
+     */
+    public static <T> void writeElement(
+        String name,
+        T that,
+        XMLStreamWriter writer,
+        ContentWriter<? super T> writeContent) {
+        writeElement(name, that, writer, false, writeContent);
+    }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlization/Xmlization.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlization/Xmlization.java
new file mode 100644
index 000000000..cbbf6c23e
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/main/java/dummy/xmlization/Xmlization.java
@@ -0,0 +1,1255 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.xmlization;
+
+import javax.xml.stream.events.XMLEvent;
+import javax.xml.stream.XMLEventReader;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamWriter;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.function.Function;
+import java.util.List;
+import java.util.Optional;
+import java.util.regex.Pattern;
+import dummy.common.*;
+import dummy.reporting.Reporting;
+import dummy.stringification.Stringification;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import dummy.visitation.*;
+import dummy.xmlcommon.XmlCommon;
+
+/**
+ * Provide de/serialization of meta-model classes to/from XML.
+ */
+public class Xmlization {
+  /**
+   * The XML namespace of the meta-model
+   */
+  public static final String NAMESPACE =
+    XmlCommon.NAMESPACE;
+
+
+  /**
+   * Implement the deserialization of meta-model classes from XML.
+   *
+   * <p>The implementation propagates an {@link Reporting.Error} instead of
+   * relying on exceptions. Under the assumption that incorrect data is much less
+   * frequent than correct data, this makes the deserialization more
+   * efficient.
+   *
+   * <p>However, we do not want to force the client to deal with
+   * the {@link Reporting.Error} class as this is not intuitive.
+   * Therefore we distinguish the implementation, realized in
+   * {@link _DeserializeImplementation}, and the facade given in
+   * {@link Deserialize} class.
+   */
+  private static class _DeserializeImplementation
+  {
+    private static void skipStartDocument(XMLEventReader reader){
+      if (XmlCommon.currentEvent(reader).isStartDocument()){
+        reader.next();
+      }
+    }
+
+    /**
+     * Convert the text content of an element which has already been opened.
+     */
+    @FunctionalInterface
+    private interface ContentConverter<T> {
+      T convert(XMLEventReader reader) throws XMLStreamException;
+    }
+
+    private static Long readContentAsLong(XMLEventReader reader) throws XMLStreamException {
+      final StringBuilder content = new StringBuilder();
+
+      while (reader.peek().isCharacters() || reader.peek().getEventType() == XMLStreamConstants.COMMENT) {
+        if (reader.peek().isCharacters()) {
+          content.append(reader.peek().asCharacters().getData());
+        }
+        reader.nextEvent();
+      }
+
+      return Long.valueOf(XmlCommon.collapseWhitespace(content.toString()));
+    }
+
+    /**
+     * Read the text content of an element and convert it with
+     * {@code convert}.
+     *
+     * <p>A self-closing element is an error, since there is no text to convert.
+     */
+    private static <T> Reporting.Result<T> readText(
+      XMLEventReader reader,
+      boolean isEmpty,
+      ContentConverter<T> convert,
+      String typeName) {
+      if (isEmpty) {
+        return Reporting.Result.failure(new Reporting.Error(
+          "Expected an XML content representing " + typeName +
+          ", but encountered a self-closing element"));
+      }
+
+      if (XmlCommon.currentEvent(reader).isEndDocument()) {
+        return Reporting.Result.failure(new Reporting.Error(
+          "Expected an XML content representing " + typeName +
+          ", but reached the end-of-file"));
+      }
+
+      try {
+        return Reporting.Result.success(convert.convert(reader));
+      } catch (Exception exception) {
+        return Reporting.Result.failure(new Reporting.Error(
+          "The XML content could not be de-serialized as " + typeName + ": " +
+          exception.getMessage()));
+      }
+    }
+
+    /**
+     * Read the text content of an element and convert it with
+     * {@code convert}, giving {@code whenEmpty} for a self-closing element.
+     */
+    private static <T> Reporting.Result<T> readText(
+      XMLEventReader reader,
+      boolean isEmpty,
+      ContentConverter<T> convert,
+      String typeName,
+      T whenEmpty) {
+      if (isEmpty) {
+        return Reporting.Result.success(whenEmpty);
+      }
+
+      return readText(reader, isEmpty, convert, typeName);
+    }
+
+    /**
+     * Read the items of a list, each with {@code readItem}.
+     *
+     * <p>Every start element is considered to mark the start of an item. Reading
+     * stops as soon as a non-start element is encountered.
+     */
+    private static <T> Reporting.Result<List<T>> readList(
+      XMLEventReader reader, boolean isEmpty, XmlCommon.ElementReader<T> readItem) {
+      final List<T> result = new ArrayList<>();
+      if (isEmpty) {
+        return Reporting.Result.success(result);
+      }
+
+      XmlCommon.skipWhitespaceAndComments(reader);
+      int index = 0;
+      if (!XmlCommon.currentEvent(reader).isStartElement()) {
+        final Reporting.Error error = new Reporting.Error(
+          "Expected a start element opening an item of the list, " +
+          "but got an XML " + XmlCommon.getEventTypeAsString(XmlCommon.currentEvent(reader)));
+        return Reporting.Result.failure(error);
+      }
+
+      while (XmlCommon.currentEvent(reader).isStartElement()) {
+        final Reporting.Result<? extends T> itemResult = readItem.read(reader);
+        if (itemResult.isError()) {
+          itemResult.getError()
+            .prependSegment(
+              new Reporting.IndexSegment(index));
+          return Reporting.Result.failure(itemResult.getError());
+        }
+
+        result.add(itemResult.getResult());
+        index++;
+        XmlCommon.skipWhitespaceAndComments(reader);
+      }
+
+      return Reporting.Result.success(result);
+    }
+
+    /**
+     * Check whether the sequence of the properties has ended.
+     *
+     * <p>Only the end tag of the enclosing element concludes a sequence. Reaching
+     * the end-of-file does not -- that is an error, which
+     * {@link #peekElementName} reports when the caller goes on to read the next
+     * property.
+     */
+    private static boolean atEndOfSequence(XMLEventReader reader) {
+      XmlCommon.skipWhitespaceAndComments(reader);
+      return XmlCommon.currentEvent(reader).isEndElement();
+    }
+
+    /**
+     * Report an element which is not a property of the class {@code className}.
+     */
+    private static <T> Reporting.Result<T> unexpectedProperty(
+      String className, String elementName) {
+      return Reporting.Result.failure(new Reporting.Error(
+        "We expected properties of the class " + className + ", " +
+        "but got an unexpected element " +
+        "with the name " + elementName));
+    }
+
+    /**
+     * Report a property which the sequence of the properties gave more than once.
+     */
+    private static Reporting.Error duplicatePropertyError(String elementName) {
+      return new Reporting.Error(
+        "Property " + elementName + " occurred more than once");
+    }
+
+    /**
+     * Report a required property of the class {@code className} which the
+     * sequence of the properties did not give.
+     */
+    private static <T> Reporting.Result<T> missingRequiredProperty(
+      String propertyName, String className) {
+      return Reporting.Result.failure(new Reporting.Error(
+        "The required property " + propertyName + " has not been given " +
+        "in the XML representation of an instance of class " + className));
+    }
+
+    private static Reporting.Result<String> readTextAs_string(
+      XMLEventReader reader, boolean isEmpty) {
+      return readText(
+        reader,
+        isEmpty,
+        XmlCommon::readContentAsString,
+        "String",
+        "");
+    }
+
+    private static Reporting.Result<Long> readTextAs_long(
+      XMLEventReader reader, boolean isEmpty) {
+      return readText(
+        reader,
+        isEmpty,
+        _DeserializeImplementation::readContentAsLong,
+        "Long");
+    }
+
+    private static Reporting.Result<List<IItem>> readListOf_IItem(
+      XMLEventReader reader, boolean isEmpty) {
+      return readList(
+        reader, isEmpty, _DeserializeImplementation::readIItemFromElement);
+    }
+
+    private static Reporting.Result<List<ISomeItem>> readListOf_ISomeItem(
+      XMLEventReader reader, boolean isEmpty) {
+      return readList(
+        reader, isEmpty, _DeserializeImplementation::readISomeItemFromElement);
+    }
+
+    private static Reporting.Result<List<ISpecialItem>> readListOf_ISpecialItem(
+      XMLEventReader reader, boolean isEmpty) {
+      return readList(
+        reader, isEmpty, _DeserializeImplementation::readSpecialItemFromElement);
+    }
+
+    /**
+     * Deserialize an instance of IItem from an XML element.
+     */
+    private static Reporting.Result<? extends IItem> readIItemFromElement(
+      XMLEventReader reader) {
+      // NOTE (mristin):
+      // We only peek the name, so that the whole element can be handed on to
+      // the reader which we select below.
+      final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+      if (tryElementName.isError()) {
+        return Reporting.Result.failure(tryElementName.getError());
+      }
+
+      switch (tryElementName.getResult()) {
+        case "someItem":
+          return readSomeItemFromElement(reader);
+        case "specialItem":
+          return readSpecialItemFromElement(reader);
+        default:
+          return Reporting.Result.failure(new Reporting.Error(
+            "Unexpected element with the name " + tryElementName.getResult()));
+      }
+    }
+
+    /**
+     * Deserialize an instance of class SomeItem from a sequence of XML elements.
+     *
+     * <p>If {@code isEmptySequence} is set, we should try to deserialize
+     * the instance from an empty sequence. That is, the parent element
+     * was a self-closing element.
+     */
+    private static Reporting.Result<SomeItem> readSomeItemFromSequence(
+      XMLEventReader reader,
+      boolean isEmptySequence) {
+      String theName = null;
+      String theNickname = null;
+
+      if (!isEmptySequence) {
+        while (!atEndOfSequence(reader)) {
+          final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+          if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+          }
+
+          final String elementName = tryElementName.getResult();
+          final boolean isEmptyProperty = XmlCommon.isEmptyElement(reader);
+
+          Reporting.Error valueError = null;
+
+          switch (elementName) {
+            case "name": {
+              if (theName != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<String> value =
+                readTextAs_string(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theName = value.getResult();
+              }
+              break;
+            }
+            case "nickname": {
+              if (theNickname != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<String> value =
+                readTextAs_string(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theNickname = value.getResult();
+              }
+              break;
+            }
+            default:
+              return unexpectedProperty("SomeItem", elementName);
+          }
+
+          if (valueError != null) {
+            valueError.prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(valueError);
+          }
+
+          final Reporting.Result<XMLEvent> endResult = XmlCommon.consumeEndElement(reader, elementName);
+          if (endResult.isError()) {
+            // NOTE (mristin):
+            // Whatever unexpected node precedes the end element still lies within
+            // the property.
+            endResult.getError().prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(endResult.getError());
+          }
+        }
+      }
+
+      if (theName == null) {
+        return missingRequiredProperty("name", "SomeItem");
+      }
+
+      return Reporting.Result.success(new SomeItem(
+        theName,
+        theNickname));
+    }
+
+    /**
+     * Deserialize an instance of ISomeItem from an XML element.
+     */
+    private static Reporting.Result<? extends ISomeItem> readISomeItemFromElement(
+      XMLEventReader reader) {
+      // NOTE (mristin):
+      // We only peek the name, so that the whole element can be handed on to
+      // the reader which we select below.
+      final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+      if (tryElementName.isError()) {
+        return Reporting.Result.failure(tryElementName.getError());
+      }
+
+      switch (tryElementName.getResult()) {
+        case "specialItem":
+          return readSpecialItemFromElement(reader);
+        case "someItem":
+          return readSomeItemFromElement(reader);
+        default:
+          return Reporting.Result.failure(new Reporting.Error(
+            "Unexpected element with the name " + tryElementName.getResult()));
+      }
+    }
+
+    /**
+     * Deserialize an instance of class SomeItem from an XML element.
+     */
+    private static Reporting.Result<? extends SomeItem> readSomeItemFromElement(
+      XMLEventReader reader) {
+      return XmlCommon.readNamedElement(
+        reader,
+        "someItem",
+        _DeserializeImplementation::readSomeItemFromSequence);
+    }
+
+    /**
+     * Deserialize an instance of class SpecialItem from a sequence of XML elements.
+     *
+     * <p>If {@code isEmptySequence} is set, we should try to deserialize
+     * the instance from an empty sequence. That is, the parent element
+     * was a self-closing element.
+     */
+    private static Reporting.Result<SpecialItem> readSpecialItemFromSequence(
+      XMLEventReader reader,
+      boolean isEmptySequence) {
+      String theName = null;
+      String theNickname = null;
+      Long theLevel = null;
+
+      if (!isEmptySequence) {
+        while (!atEndOfSequence(reader)) {
+          final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+          if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+          }
+
+          final String elementName = tryElementName.getResult();
+          final boolean isEmptyProperty = XmlCommon.isEmptyElement(reader);
+
+          Reporting.Error valueError = null;
+
+          switch (elementName) {
+            case "name": {
+              if (theName != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<String> value =
+                readTextAs_string(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theName = value.getResult();
+              }
+              break;
+            }
+            case "nickname": {
+              if (theNickname != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<String> value =
+                readTextAs_string(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theNickname = value.getResult();
+              }
+              break;
+            }
+            case "level": {
+              if (theLevel != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<Long> value =
+                readTextAs_long(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theLevel = value.getResult();
+              }
+              break;
+            }
+            default:
+              return unexpectedProperty("SpecialItem", elementName);
+          }
+
+          if (valueError != null) {
+            valueError.prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(valueError);
+          }
+
+          final Reporting.Result<XMLEvent> endResult = XmlCommon.consumeEndElement(reader, elementName);
+          if (endResult.isError()) {
+            // NOTE (mristin):
+            // Whatever unexpected node precedes the end element still lies within
+            // the property.
+            endResult.getError().prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(endResult.getError());
+          }
+        }
+      }
+
+      if (theName == null) {
+        return missingRequiredProperty("name", "SpecialItem");
+      }
+
+      if (theLevel == null) {
+        return missingRequiredProperty("level", "SpecialItem");
+      }
+
+      return Reporting.Result.success(new SpecialItem(
+        theName,
+        theLevel,
+        theNickname));
+    }
+
+    /**
+     * Deserialize an instance of class SpecialItem from an XML element.
+     */
+    private static Reporting.Result<? extends SpecialItem> readSpecialItemFromElement(
+      XMLEventReader reader) {
+      return XmlCommon.readNamedElement(
+        reader,
+        "specialItem",
+        _DeserializeImplementation::readSpecialItemFromSequence);
+    }
+
+    /**
+     * Deserialize an instance of class Container from a sequence of XML elements.
+     *
+     * <p>If {@code isEmptySequence} is set, we should try to deserialize
+     * the instance from an empty sequence. That is, the parent element
+     * was a self-closing element.
+     */
+    private static Reporting.Result<Container> readContainerFromSequence(
+      XMLEventReader reader,
+      boolean isEmptySequence) {
+      List<IItem> theItems = null;
+      List<ISomeItem> theSomeItems = null;
+      List<ISpecialItem> theSpecialItems = null;
+
+      if (!isEmptySequence) {
+        while (!atEndOfSequence(reader)) {
+          final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+          if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+          }
+
+          final String elementName = tryElementName.getResult();
+          final boolean isEmptyProperty = XmlCommon.isEmptyElement(reader);
+
+          Reporting.Error valueError = null;
+
+          switch (elementName) {
+            case "items": {
+              if (theItems != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<List<IItem>> value =
+                readListOf_IItem(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theItems = value.getResult();
+              }
+              break;
+            }
+            case "someItems": {
+              if (theSomeItems != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<List<ISomeItem>> value =
+                readListOf_ISomeItem(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theSomeItems = value.getResult();
+              }
+              break;
+            }
+            case "specialItems": {
+              if (theSpecialItems != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<List<ISpecialItem>> value =
+                readListOf_ISpecialItem(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theSpecialItems = value.getResult();
+              }
+              break;
+            }
+            default:
+              return unexpectedProperty("Container", elementName);
+          }
+
+          if (valueError != null) {
+            valueError.prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(valueError);
+          }
+
+          final Reporting.Result<XMLEvent> endResult = XmlCommon.consumeEndElement(reader, elementName);
+          if (endResult.isError()) {
+            // NOTE (mristin):
+            // Whatever unexpected node precedes the end element still lies within
+            // the property.
+            endResult.getError().prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(endResult.getError());
+          }
+        }
+      }
+
+      if (theItems == null) {
+        return missingRequiredProperty("items", "Container");
+      }
+
+      if (theSomeItems == null) {
+        return missingRequiredProperty("someItems", "Container");
+      }
+
+      return Reporting.Result.success(new Container(
+        theItems,
+        theSomeItems,
+        theSpecialItems));
+    }
+
+    /**
+     * Deserialize an instance of class Container from an XML element.
+     */
+    private static Reporting.Result<? extends Container> readContainerFromElement(
+      XMLEventReader reader) {
+      return XmlCommon.readNamedElement(
+        reader,
+        "container",
+        _DeserializeImplementation::readContainerFromSequence);
+    }
+
+    /**
+     * Deserialize an instance of class Wrapper from a sequence of XML elements.
+     *
+     * <p>If {@code isEmptySequence} is set, we should try to deserialize
+     * the instance from an empty sequence. That is, the parent element
+     * was a self-closing element.
+     */
+    private static Reporting.Result<Wrapper> readWrapperFromSequence(
+      XMLEventReader reader,
+      boolean isEmptySequence) {
+      IContainer theContainer = null;
+
+      if (!isEmptySequence) {
+        while (!atEndOfSequence(reader)) {
+          final Reporting.Result<String> tryElementName = XmlCommon.peekElementName(reader);
+          if (tryElementName.isError()) {
+            return Reporting.Result.failure(tryElementName.getError());
+          }
+
+          final String elementName = tryElementName.getResult();
+          final boolean isEmptyProperty = XmlCommon.isEmptyElement(reader);
+
+          Reporting.Error valueError = null;
+
+          switch (elementName) {
+            case "container": {
+              if (theContainer != null) {
+                valueError = duplicatePropertyError(elementName);
+                break;
+              }
+
+              final Reporting.Result<Container> value =
+                readContainerFromSequence(reader, isEmptyProperty);
+              if (value.isError()) {
+                valueError = value.getError();
+              } else {
+                theContainer = value.getResult();
+              }
+              break;
+            }
+            default:
+              return unexpectedProperty("Wrapper", elementName);
+          }
+
+          if (valueError != null) {
+            valueError.prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(valueError);
+          }
+
+          final Reporting.Result<XMLEvent> endResult = XmlCommon.consumeEndElement(reader, elementName);
+          if (endResult.isError()) {
+            // NOTE (mristin):
+            // Whatever unexpected node precedes the end element still lies within
+            // the property.
+            endResult.getError().prependSegment(
+              new Reporting.NameSegment(
+                elementName));
+            return Reporting.Result.failure(endResult.getError());
+          }
+        }
+      }
+
+      if (theContainer == null) {
+        return missingRequiredProperty("container", "Wrapper");
+      }
+
+      return Reporting.Result.success(new Wrapper(
+        theContainer));
+    }
+
+    /**
+     * Deserialize an instance of class Wrapper from an XML element.
+     */
+    private static Reporting.Result<? extends Wrapper> readWrapperFromElement(
+      XMLEventReader reader) {
+      return XmlCommon.readNamedElement(
+        reader,
+        "wrapper",
+        _DeserializeImplementation::readWrapperFromSequence);
+    }
+  }
+
+  /**
+   * Deserialize instances of meta-model classes from XML.
+   */
+  /** <pre>
+   * Here is an example how to parse an instance of class IItem:
+   * {@code
+   * XMLEventReader reader = xmlFactory.createXMLEventReader(...some arguments...);
+   * IItem anInstance = Deserialize.deserializeIItem(
+   *   reader);
+   * }
+   * </pre>
+   *
+   * <pre>
+   * If the elements live in a namespace, you have to supply it. For example:
+   * {@code
+   * XMLEventReader reader = xmlFactory.createXMLEventReader(...some arguments...);
+   * IItem anInstance = Deserialize.deserializeIItem(
+   *   reader,
+   *   "http://www.example.com/5/12");
+   * }
+   * </pre>
+   */
+  public static class Deserialize
+  {
+    /**
+     * Deserialize an instance of IItem from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static IItem deserializeIItem(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends IItem> result =
+        _DeserializeImplementation.readIItemFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+
+    /**
+     * Deserialize an instance of ISomeItem from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static ISomeItem deserializeISomeItem(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends ISomeItem> result =
+        _DeserializeImplementation.readISomeItemFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+
+    /**
+     * Deserialize an instance of SomeItem from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static SomeItem deserializeSomeItem(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends SomeItem> result =
+        _DeserializeImplementation.readSomeItemFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+
+    /**
+     * Deserialize an instance of SpecialItem from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static SpecialItem deserializeSpecialItem(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends SpecialItem> result =
+        _DeserializeImplementation.readSpecialItemFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+
+    /**
+     * Deserialize an instance of Container from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static Container deserializeContainer(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends Container> result =
+        _DeserializeImplementation.readContainerFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+
+    /**
+     * Deserialize an instance of Wrapper from {@code reader}.
+     *
+     * @param reader Initialized XML reader with reader.peek() set to the element
+     */
+    public static Wrapper deserializeWrapper(
+      XMLEventReader reader) {
+
+      _DeserializeImplementation.skipStartDocument(reader);
+      XmlCommon.skipWhitespaceAndComments(reader);
+
+      // NOTE (mristin):
+      // The path starts at the root element as it is in the document, which
+      // might well be another element than the expected one.
+      final String rootElementName = (
+        XmlCommon.currentEvent(reader).isStartElement()
+          ? XmlCommon.currentEvent(reader).asStartElement().getName().getLocalPart()
+          : null);
+
+      Reporting.Result<? extends Wrapper> result =
+        _DeserializeImplementation.readWrapperFromElement(
+          reader);
+
+      return result.onError(error -> {
+        if (rootElementName != null) {
+          error.prependSegment(new Reporting.NameSegment(rootElementName));
+        }
+        throw new XmlCommon.DeserializeException(
+          Reporting.generateRelativeXPath(error.getPathSegments()),
+          error.getCause());
+      });
+    }
+  }
+
+  /**
+   * Serialize recursively the instances as XML elements.
+   */
+  static class _VisitorWithWriter
+    extends AbstractVisitorWithContext<XMLStreamWriter> {
+
+    /**
+     * Declare the XML namespace on the element which this visitor writes.
+     *
+     * <p>Only the outermost element carries the declaration. The obvious
+     * alternative -- a flag cleared once the first element has been written --
+     * would be mutable state, and state forces every method of this class to be
+     * an instance method, which in turn makes every method reference to it
+     * capture {@code this} and allocate. Pinning the flag in the constructor
+     * instead costs one visitor per case, allocated once for the whole program,
+     * and lets everything else here be {@code static}.
+     */
+    private final boolean withNamespace;
+
+    private _VisitorWithWriter(boolean withNamespace) {
+      this.withNamespace = withNamespace;
+    }
+
+    /**
+     * Write the outermost element, which declares the XML namespace.
+     */
+    private static final _VisitorWithWriter ROOT =
+      new _VisitorWithWriter(true);
+
+    /**
+     * Write an element nested in another one, which never re-declares the XML
+     * namespace.
+     */
+    private static final _VisitorWithWriter NESTED =
+      new _VisitorWithWriter(false);
+
+    /**
+     * Write {@code that} as the XML element of a property called
+     * {@code name}.
+     *
+     * <p>This is {@link #writeElement} plus the one thing a property knows
+     * which nothing below it does: its own name. Prepending it here, once,
+     * saves a {@code try} around every one of the property writes.
+     *
+     * <p>The path names the getter, and not the XML element: a serialization
+     * error is reported on an <em>instance</em>, which the caller holds, and
+     * not on a document which has not been written yet.
+     */
+    private static <T> void writeProperty(
+      String name,
+      String getterName,
+      T that,
+      XMLStreamWriter writer,
+      XmlCommon.ContentWriter<? super T> writeContent) {
+      try {
+        XmlCommon.writeElement(name, that, writer, writeContent);
+      } catch (XmlCommon.SerializeFailure failure) {
+        failure.getError().prependSegment(
+          new Reporting.NameSegment(getterName));
+        throw failure;
+      }
+    }
+
+    /**
+     * Write {@code that} as the XML element of a property called
+     * {@code name} if it has been given, and write nothing at all otherwise.
+     *
+     * <p>The {@link Optional} is taken apart here, once, instead of at every
+     * optional property: asking it and then unwrapping it at the call site
+     * would call the getter twice, and every call allocates an
+     * {@link Optional} of its own.
+     */
+    private static <T> void writeOptionalProperty(
+      String name,
+      String getterName,
+      Optional<T> that,
+      XMLStreamWriter writer,
+      XmlCommon.ContentWriter<? super T> writeContent) {
+      final T value = that.orElse(null);
+      if (value != null) {
+        writeProperty(name, getterName, value, writer, writeContent);
+      }
+    }
+
+    /**
+     * Write {@code that} as its own, self-describing XML element.
+     *
+     * <p>Which element that is, is decided by the run-time type of
+     * {@code that}, so this one writer serves every abstract class, every
+     * concrete class with descendants, and the item of a list or of a tuple of
+     * any class at all. The reading, which has to decide what to construct
+     * before it has read anything, needs a dispatcher per interface instead.
+     *
+     * <p>An element written from here is nested in another one by
+     * construction, so it goes through the visitor which does not re-declare
+     * the XML namespace.
+     */
+    private static void writeClass(
+      IClass that,
+      XMLStreamWriter writer) {
+      NESTED.visit(that, writer);
+    }
+
+    private static void writeListOf_IClass(
+      List<? extends IClass> that,
+      XMLStreamWriter writer) {
+      int index = 0;
+      try {
+        for (IClass item : that) {
+          writeClass(item, writer);
+          index++;
+        }
+      } catch (XmlCommon.SerializeFailure failure) {
+        failure.getError().prependSegment(
+          new Reporting.IndexSegment(index));
+        throw failure;
+      }
+    }
+
+    private static void writeSomeItemAsSequence(
+      ISomeItem that,
+      XMLStreamWriter writer) {
+      writeProperty(
+        "name",
+        "getName()",
+        that.getName(),
+        writer,
+        XmlCommon::writeStringifiedContent);
+
+      writeOptionalProperty(
+        "nickname",
+        "getNickname()",
+        that.getNickname(),
+        writer,
+        XmlCommon::writeStringifiedContent);
+    }
+
+    @Override
+    public void visitSomeItem(
+      ISomeItem that,
+      XMLStreamWriter writer) {
+      XmlCommon.writeElement(
+        "someItem",
+        that,
+        writer,
+        withNamespace,
+        _VisitorWithWriter::writeSomeItemAsSequence);
+    }
+
+    private static void writeSpecialItemAsSequence(
+      ISpecialItem that,
+      XMLStreamWriter writer) {
+      writeProperty(
+        "name",
+        "getName()",
+        that.getName(),
+        writer,
+        XmlCommon::writeStringifiedContent);
+
+      writeOptionalProperty(
+        "nickname",
+        "getNickname()",
+        that.getNickname(),
+        writer,
+        XmlCommon::writeStringifiedContent);
+
+      writeProperty(
+        "level",
+        "getLevel()",
+        that.getLevel(),
+        writer,
+        XmlCommon::writeStringifiedContent);
+    }
+
+    @Override
+    public void visitSpecialItem(
+      ISpecialItem that,
+      XMLStreamWriter writer) {
+      XmlCommon.writeElement(
+        "specialItem",
+        that,
+        writer,
+        withNamespace,
+        _VisitorWithWriter::writeSpecialItemAsSequence);
+    }
+
+    private static void writeContainerAsSequence(
+      IContainer that,
+      XMLStreamWriter writer) {
+      writeProperty(
+        "items",
+        "getItems()",
+        that.getItems(),
+        writer,
+        _VisitorWithWriter::writeListOf_IClass);
+
+      writeProperty(
+        "someItems",
+        "getSomeItems()",
+        that.getSomeItems(),
+        writer,
+        _VisitorWithWriter::writeListOf_IClass);
+
+      writeOptionalProperty(
+        "specialItems",
+        "getSpecialItems()",
+        that.getSpecialItems(),
+        writer,
+        _VisitorWithWriter::writeListOf_IClass);
+    }
+
+    @Override
+    public void visitContainer(
+      IContainer that,
+      XMLStreamWriter writer) {
+      XmlCommon.writeElement(
+        "container",
+        that,
+        writer,
+        withNamespace,
+        _VisitorWithWriter::writeContainerAsSequence);
+    }
+
+    private static void writeWrapperAsSequence(
+      IWrapper that,
+      XMLStreamWriter writer) {
+      writeProperty(
+        "container",
+        "getContainer()",
+        that.getContainer(),
+        writer,
+        _VisitorWithWriter::writeContainerAsSequence);
+    }
+
+    @Override
+    public void visitWrapper(
+      IWrapper that,
+      XMLStreamWriter writer) {
+      XmlCommon.writeElement(
+        "wrapper",
+        that,
+        writer,
+        withNamespace,
+        _VisitorWithWriter::writeWrapperAsSequence);
+    }
+  }
+
+  /**
+   * Serialize instances of meta-model classes to XML.
+   */
+  /**
+   * <pre>
+   * Here is an example how to serialize an instance of IItem:
+   * {@code
+   * IClass anInstance = new IItem(
+   *     ... some constructor arguments ...
+   * );
+   * XMLStreamWriter writer = xmlWriterFactory.createXMLStreamWriter(...some arguments...);
+   * Serialize.to(
+   *   anInstance,
+   *   writer);
+   * }
+   * </pre>
+   */
+  public static class Serialize
+  {
+    /**
+     * Serialize an instance of the meta-model to XML.
+     *
+     * <p>{@code writer} is flushed exactly once, here at the end. Nothing is
+     * flushed in-between, which is what lets {@link XMLStreamWriter} buffer,
+     * and the single flush at the end is what lets a failure of the underlying
+     * stream be reported as a {@link XmlCommon.SerializeException} from this method --
+     * were it left to the caller, the failure would surface at their own flush,
+     * after the serialization has long returned.
+     *
+     * <p>The path of a {@link XmlCommon.SerializeException} is rendered as
+     * a Java access path, and not as the relative XPath the de-serialization
+     * reports: the caller invoked this on an <em>instance</em>, and not on
+     * a document, which has not been written yet. It names the getters and
+     * the indices leading to the culprit, so that
+     * {@code getSubmodelElements().get(0).getValue()} can be pasted as it
+     * stands. The outermost element is deliberately not named, as this method
+     * takes any {@link IClass} and the name would say nothing the caller does
+     * not already know.
+     */
+    public static void to(
+      IClass that,
+      XMLStreamWriter writer) throws XmlCommon.SerializeException {
+      try {
+        _VisitorWithWriter.ROOT.visit(
+          that, writer);
+        writer.flush();
+      } catch (XMLStreamException exception) {
+        throw new XmlCommon.SerializeException("", exception.getMessage());
+      } catch (XmlCommon.SerializeFailure failure) {
+        final Reporting.Error error = failure.getError();
+        throw new XmlCommon.SerializeException(
+          Reporting.generateJavaPath(error.getPathSegments()),
+          error.getCause());
+      }
+    }
+  }
+}
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/Common.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/Common.java
new file mode 100644
index 000000000..b8d78465f
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/Common.java
@@ -0,0 +1,150 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import dummy.reporting.Reporting;
+import dummy.types.model.IClass;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+/**
+ * Provide common functionality to be re-used across different tests
+ * such as reading of environment variables.
+ */
+public class Common {
+  public static String TEST_DATA_DIR = Paths.get("test_data").toAbsolutePath().toString();
+
+  public static final String RECORD_MODE_ENVIRONMENT_VARIABLE_NAME =
+    "DUMMY_TESTS_RECORD_MODE";
+
+  // NOTE (empwilli):
+  // It is tedious to record manually all the expected error messages.
+  // Therefore we include this variable to steer the automatic recording.
+  // We intentionally inter-twine the recording code with the test code
+  // to keep them close to each other so that they are easier to maintain.
+  public static final boolean RECORD_MODE =
+    System.getenv("DUMMY_TESTS_RECORD_MODE") != null && (
+      System.getenv(RECORD_MODE_ENVIRONMENT_VARIABLE_NAME).equalsIgnoreCase("true") ||
+      System.getenv(RECORD_MODE_ENVIRONMENT_VARIABLE_NAME).equalsIgnoreCase("on") ||
+      System.getenv(RECORD_MODE_ENVIRONMENT_VARIABLE_NAME).equalsIgnoreCase("1") ||
+      System.getenv(RECORD_MODE_ENVIRONMENT_VARIABLE_NAME).equalsIgnoreCase("yes"));
+
+  @SuppressWarnings("unchecked")
+  public static <T extends IClass> T mustFind(IClass container, Class<T> type) {
+    if (type.isInstance(container)) {
+      return type.cast(container);
+    }
+    for (IClass current : container.descend()) {
+      if (type.isInstance(current)) {
+        return type.cast(current);
+      }
+    }
+    throw new IllegalStateException("No instance of " + type.getSimpleName() + " could be found");
+  }
+
+  public static List<Path> findPaths(Path path, String fileExtension) throws IOException {
+    if (!Files.isDirectory(path)) {
+      throw new IllegalArgumentException("Path must be a directory!");
+    }
+
+    List<Path> result;
+    try (Stream<Path> walk = Files.walk(path)) {
+      result =
+        walk.filter(p -> !Files.isDirectory(p))
+          .filter(f -> f.toString().endsWith(fileExtension))
+          .collect(Collectors.toList());
+    }
+    return result;
+  }
+
+  public static List<Path> findDirs(Path path) throws IOException {
+    if (!Files.isDirectory(path)) {
+      throw new IllegalArgumentException("Path must be a directory!");
+    }
+
+    List<Path> result;
+    try (Stream<Path> walk = Files.walk(path)) {
+      result = walk.filter(p -> Files.isDirectory(p)).collect(Collectors.toList());
+    }
+    return result;
+  }
+
+  public static <T> List<T> asList(Iterable<T> iterable) {
+    return StreamSupport.stream(iterable.spliterator(), false).collect(Collectors.toList());
+  }
+
+  public static void assertNoVerificationErrors(List<Reporting.Error> errors, Path path) {
+    if (!errors.isEmpty()) {
+      StringBuilder stringBuilder = new StringBuilder();
+      stringBuilder
+        .append("Expected no errors when verifying the instance de-serialized from ")
+        .append(path.toString())
+        .append(", ")
+        .append("but got ")
+        .append(errors.size())
+        .append(" error(s):")
+        .append(System.lineSeparator());
+      for (Reporting.Error error : errors) {
+        stringBuilder
+          .append(Reporting.generateJsonPath(error.getPathSegments()))
+          .append(": ")
+          .append(error.getCause());
+      }
+      fail(stringBuilder.toString());
+    }
+  }
+
+  public static void assertEqualsExpectedOrRerecordVerificationErrors(
+    List<Reporting.Error> errors, Path path) throws IOException {
+    if (errors.isEmpty()) {
+      fail("Expected at least one verification error when verifying " + path + ", but got none");
+    }
+    final String got =
+      errors.stream()
+        .map(
+          error ->
+            Reporting.generateJsonPath(error.getPathSegments()) + ": " + error.getCause())
+              .collect(Collectors.joining(";\n"));
+    final Path errorsPath = Paths.get(path + ".errors");
+    if (RECORD_MODE) {
+      Files.write(errorsPath, got.getBytes(StandardCharsets.UTF_8));
+    } else {
+      if (!Files.exists(errorsPath)) {
+        throw new FileNotFoundException(
+          "The file with the recorded errors does not exist: "
+            + errorsPath
+            + "; maybe you want to set the environment variable "
+            + Common.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME);
+      }
+      final String expected = String.join("\n", Files.readAllLines(errorsPath));
+      assertEquals(
+        expected,
+        got,
+        "The expected verification errors do not match the actual ones for the file " + path);
+    }
+  }
+
+  public static String trace(IClass instance)
+  {
+    return instance.getClass().getName();
+  }
+} // class Common
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJson.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJson.java
new file mode 100644
index 000000000..be63ff1f7
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJson.java
@@ -0,0 +1,98 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.jsonization.Jsonization;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.*;
+import java.io.IOException;
+import java.nio.file.Path;
+
+public final class CommonJson {
+  public static JsonNode readFromFile(Path path) {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    JsonNode node;
+    try {
+      node = objectMapper.readTree(path.toFile());
+    } catch (JsonParseException exception) {
+      throw new IllegalStateException(
+        "Expected the file to be a valid JSON, but it was not: "
+          + path + "; exception was: "
+          + exception);
+    } catch (JsonProcessingException exception) {
+      throw new IllegalStateException(
+        "Expected the file to be a valid JSON, but it was not: "
+          + path + "; exception was: "
+          + exception);
+    } catch (IOException exception) {
+      throw new IllegalStateException(
+        "Expected the file to be a valid JSON, but it was not: "
+          + path + "; exception was: "
+          + exception);
+    }
+    return node;
+  }
+
+  /**
+   *  Serialize something to a uniform JSON text
+   *  such that we can use it for comparisons in the tests.
+   */
+  public static JsonNode toJson(Object something)
+  {
+    if (something instanceof Boolean) {
+      return BooleanNode.valueOf((Boolean) something);
+    } else if (something instanceof Integer) {
+      return IntNode.valueOf((Integer) something);
+    } else if (something instanceof Double) {
+      return DoubleNode.valueOf((Double) something);
+    } else if (something instanceof String) {
+      return TextNode.valueOf((String) something);
+    } else if (something instanceof byte[]) {
+      return BinaryNode.valueOf((byte[]) something);
+    } else if (something instanceof IClass) {
+      return Jsonization.Serialize.toJsonObject((IClass) something);
+    } else {
+      throw new IllegalArgumentException(
+        "The conversion of type "
+          + something.getClass().toString()
+          + " to a JSON node has not been defined: "
+          + something.toString());
+    }
+  }
+
+  /**
+   * Infer the node kind of the JSON node.
+   */
+  // TODO check whether this is really necessary
+  private static String getNodeKind(JsonNode node)
+  {
+    if (node.isArray()) {
+      return "array";
+    } else if (node.isObject()) {
+      return "object";
+    } else if (node.isValueNode()) {
+      return "value";
+    } else {
+      throw new IllegalStateException(
+        "Unhandled JsonNode: " + node.getNodeType().toString());
+    }
+  }
+} // public final class CommonJson
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJsonization.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJsonization.java
new file mode 100644
index 000000000..39ce9f1f9
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/CommonJsonization.java
@@ -0,0 +1,129 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import dummy.jsonization.Jsonization;
+import dummy.types.impl.*;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+/**
+ * Provide methods to load instances from JSON test data.
+ */
+public final class CommonJsonization {
+  public static SomeItem loadMaximalSomeItem() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SomeItem",
+      "maximal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeSomeItem(node);
+  } // public static SomeItem loadMaximalSomeItem
+
+  public static SomeItem loadMinimalSomeItem() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SomeItem",
+      "minimal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeSomeItem(node);
+  } // public static SomeItem loadMinimalSomeItem
+
+  public static SpecialItem loadMaximalSpecialItem() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SpecialItem",
+      "maximal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeSpecialItem(node);
+  } // public static SpecialItem loadMaximalSpecialItem
+
+  public static SpecialItem loadMinimalSpecialItem() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SpecialItem",
+      "minimal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeSpecialItem(node);
+  } // public static SpecialItem loadMinimalSpecialItem
+
+  public static Container loadMaximalContainer() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Container",
+      "maximal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeContainer(node);
+  } // public static Container loadMaximalContainer
+
+  public static Container loadMinimalContainer() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Container",
+      "minimal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeContainer(node);
+  } // public static Container loadMinimalContainer
+
+  public static Wrapper loadMaximalWrapper() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Wrapper",
+      "maximal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeWrapper(node);
+  } // public static Wrapper loadMaximalWrapper
+
+  public static Wrapper loadMinimalWrapper() throws IOException {
+    final Path path = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Wrapper",
+      "minimal.json");
+
+    final JsonNode node = CommonJson.readFromFile(path);
+
+    return Jsonization.Deserialize.deserializeWrapper(node);
+  } // public static Wrapper loadMinimalWrapper
+} // class CommonJsonization
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestCopying.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestCopying.java
new file mode 100644
index 000000000..7dbcdfdf2
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestCopying.java
@@ -0,0 +1,265 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import dummy.common.*;
+import dummy.copying.Copying;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import dummy.types.model.IClass;
+import dummy.visitation.AbstractTransformerWithContext;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+public class TestCopying {
+  private static class _DeepEqualiser extends AbstractTransformerWithContext<IClass, Boolean> {
+    @Override
+    public Boolean transformSomeItem(ISomeItem that, IClass other) {
+      if (!(other instanceof SomeItem)) {
+        return false;
+      }
+
+      SomeItem casted = (SomeItem) other;
+
+      return (
+        that.getName().equals(casted.getName())
+        && that.getNickname().equals(casted.getNickname()));
+    }
+
+    @Override
+    public Boolean transformSpecialItem(ISpecialItem that, IClass other) {
+      if (!(other instanceof SpecialItem)) {
+        return false;
+      }
+
+      SpecialItem casted = (SpecialItem) other;
+
+      return (
+        that.getName().equals(casted.getName())
+        && that.getNickname().equals(casted.getNickname())
+        && that.getLevel().equals(casted.getLevel()));
+    }
+
+    @Override
+    public Boolean transformContainer(IContainer that, IClass other) {
+      if (!(other instanceof Container)) {
+        return false;
+      }
+
+      Container casted = (Container) other;
+
+      return (
+        deepEqualsListOf_IItem(that.getItems(), casted.getItems())
+        && deepEqualsListOf_ISomeItem(that.getSomeItems(), casted.getSomeItems())
+        && (that.getSpecialItems().isPresent()
+          ? casted.getSpecialItems().isPresent()
+            && deepEqualsListOf_ISpecialItem(that.getSpecialItems().get(), casted.getSpecialItems().get())
+          : !casted.getSpecialItems().isPresent()));
+    }
+
+    @Override
+    public Boolean transformWrapper(IWrapper that, IClass other) {
+      if (!(other instanceof Wrapper)) {
+        return false;
+      }
+
+      Wrapper casted = (Wrapper) other;
+
+      return (
+        transform(that.getContainer(), casted.getContainer()));
+    }
+
+    private Boolean deepEqualsListOf_IItem(
+      List<IItem> that,
+      List<IItem> other) {
+      if (that.size() != other.size()) {
+        return false;
+      }
+
+      for (int i = 0; i < that.size(); i++) {
+        if (!transform(that.get(i), other.get(i))) {
+          return false;
+        }
+      }
+
+      return true;
+    }
+
+    private Boolean deepEqualsListOf_ISomeItem(
+      List<ISomeItem> that,
+      List<ISomeItem> other) {
+      if (that.size() != other.size()) {
+        return false;
+      }
+
+      for (int i = 0; i < that.size(); i++) {
+        if (!transform(that.get(i), other.get(i))) {
+          return false;
+        }
+      }
+
+      return true;
+    }
+
+    private Boolean deepEqualsListOf_ISpecialItem(
+      List<ISpecialItem> that,
+      List<ISpecialItem> other) {
+      if (that.size() != other.size()) {
+        return false;
+      }
+
+      for (int i = 0; i < that.size(); i++) {
+        if (!transform(that.get(i), other.get(i))) {
+          return false;
+        }
+      }
+
+      return true;
+    }
+  } // class _DeepEqualiser
+
+  private static final _DeepEqualiser DeepEqualiserInstance = new _DeepEqualiser();
+
+  private static Boolean SomeItemShallowEquals(
+    SomeItem that,
+    SomeItem other) {
+    return (
+      that.getName().equals(other.getName())
+      && that.getNickname().equals(other.getNickname()));
+  }
+
+  private static Boolean SpecialItemShallowEquals(
+    SpecialItem that,
+    SpecialItem other) {
+    return (
+      that.getName().equals(other.getName())
+      && that.getNickname().equals(other.getNickname())
+      && that.getLevel().equals(other.getLevel()));
+  }
+
+  private static Boolean ContainerShallowEquals(
+    Container that,
+    Container other) {
+    return (
+      that.getItems().equals(other.getItems())
+      && that.getSomeItems().equals(other.getSomeItems())
+      && that.getSpecialItems().equals(other.getSpecialItems()));
+  }
+
+  private static Boolean WrapperShallowEquals(
+    Wrapper that,
+    Wrapper other) {
+    return that.getContainer().equals(other.getContainer());
+  }
+
+  private static Boolean SomeItemDeepEquals(SomeItem that, SomeItem other) {
+    return DeepEqualiserInstance.transform(that, other);
+  }
+
+  private static Boolean SpecialItemDeepEquals(SpecialItem that, SpecialItem other) {
+    return DeepEqualiserInstance.transform(that, other);
+  }
+
+  private static Boolean ContainerDeepEquals(Container that, Container other) {
+    return DeepEqualiserInstance.transform(that, other);
+  }
+
+  private static Boolean WrapperDeepEquals(Wrapper that, Wrapper other) {
+    return DeepEqualiserInstance.transform(that, other);
+  }
+
+  @Test
+  public void testSomeItemShallowCopy() throws IOException {
+    final SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+    final SomeItem instanceCopy = Copying.shallow(instance);
+
+    assertTrue(
+      SomeItemShallowEquals(instance, instanceCopy),
+      "SomeItem");
+  } // public void testSomeItemShallowCopy
+
+  @Test
+  public void testSomeItemDeepCopy() throws IOException {
+    final SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+    final SomeItem instanceCopy = Copying.deep(instance);
+
+    assertTrue(
+      SomeItemDeepEquals(instance, instanceCopy),
+      "SomeItem");
+  } // public void testSomeItemDeepCopy
+
+  @Test
+  public void testSpecialItemShallowCopy() throws IOException {
+    final SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+    final SpecialItem instanceCopy = Copying.shallow(instance);
+
+    assertTrue(
+      SpecialItemShallowEquals(instance, instanceCopy),
+      "SpecialItem");
+  } // public void testSpecialItemShallowCopy
+
+  @Test
+  public void testSpecialItemDeepCopy() throws IOException {
+    final SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+    final SpecialItem instanceCopy = Copying.deep(instance);
+
+    assertTrue(
+      SpecialItemDeepEquals(instance, instanceCopy),
+      "SpecialItem");
+  } // public void testSpecialItemDeepCopy
+
+  @Test
+  public void testContainerShallowCopy() throws IOException {
+    final Container instance = CommonJsonization.loadMaximalContainer();
+    final Container instanceCopy = Copying.shallow(instance);
+
+    assertTrue(
+      ContainerShallowEquals(instance, instanceCopy),
+      "Container");
+  } // public void testContainerShallowCopy
+
+  @Test
+  public void testContainerDeepCopy() throws IOException {
+    final Container instance = CommonJsonization.loadMaximalContainer();
+    final Container instanceCopy = Copying.deep(instance);
+
+    assertTrue(
+      ContainerDeepEquals(instance, instanceCopy),
+      "Container");
+  } // public void testContainerDeepCopy
+
+  @Test
+  public void testWrapperShallowCopy() throws IOException {
+    final Wrapper instance = CommonJsonization.loadMaximalWrapper();
+    final Wrapper instanceCopy = Copying.shallow(instance);
+
+    assertTrue(
+      WrapperShallowEquals(instance, instanceCopy),
+      "Wrapper");
+  } // public void testWrapperShallowCopy
+
+  @Test
+  public void testWrapperDeepCopy() throws IOException {
+    final Wrapper instance = CommonJsonization.loadMaximalWrapper();
+    final Wrapper instanceCopy = Copying.deep(instance);
+
+    assertTrue(
+      WrapperDeepEquals(instance, instanceCopy),
+      "Wrapper");
+  } // public void testWrapperDeepCopy
+} // class TestCopying
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendAndVisitorThrough.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendAndVisitorThrough.java
new file mode 100644
index 000000000..15d6458ca
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendAndVisitorThrough.java
@@ -0,0 +1,166 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import dummy.types.impl.*;
+import dummy.types.model.IClass;
+import dummy.visitation.VisitorThrough;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+
+public class TestDescendAndVisitorThrough {
+  private class _TracingVisitorThrough extends VisitorThrough {
+      public final List<String> log = new ArrayList<>();
+
+      @Override
+      public void visit(IClass that) {
+        log.add(Common.trace(that));
+        super.visit(that);
+      }
+    }
+
+    private void assertDescendAndVisitorThroughSame(IClass instance)
+    {
+      final List<String> logFromDescend = new ArrayList<>();
+
+      for (IClass subInstance : instance.descend()) {
+        logFromDescend.add(Common.trace(subInstance));
+      }
+
+      final _TracingVisitorThrough visitor = new _TracingVisitorThrough();
+      visitor.visit(instance);
+      final List<String> traceFromVisitor = visitor.log;
+
+      assertFalse(traceFromVisitor.isEmpty());
+
+      assertEquals(Common.trace(instance), traceFromVisitor.get(0));
+
+      traceFromVisitor.remove(0);
+
+      assertTrue(traceFromVisitor.equals(logFromDescend));
+    }
+
+    private void compareOrRerecordTrace(IClass instance, Path expectedPath) throws IOException {
+      final StringBuilder stringBuilder = new StringBuilder();
+      for (IClass descendant : instance.descend()) {
+        stringBuilder.append(Common.trace(descendant));
+      }
+
+      final String got = stringBuilder.toString();
+      if (Common.RECORD_MODE) {
+        Files.createDirectories(expectedPath.getParent());
+        Files.write(expectedPath, got.getBytes());
+      } else {
+        if (!Files.exists(expectedPath)) {
+          throw new FileNotFoundException(
+              "The file with the recorded value does not exist: " + expectedPath);
+        }
+        final String expected =
+            Files.readAllLines(expectedPath).stream().collect(Collectors.joining("\n"));
+        assertEquals(expected.replace("\n", ""), got.replace("\n", ""));
+      }
+    }
+
+    @Test
+    public void testDescendOfSomeItem() throws IOException {
+      final SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+
+      compareOrRerecordTrace(
+        instance,
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Descend",
+          "SomeItem",
+          "maximal.json.trace"));
+    } // public void testDescendOfSomeItem
+
+    @Test
+    public void testDescendAgainstVisitorThroughForSomeItem() throws IOException {
+      SomeItem instance = (
+        CommonJsonization.loadMaximalSomeItem());
+
+      assertDescendAndVisitorThroughSame(instance);
+    } // public void testDescendAgainstVisitorThroughForSomeItem
+
+    @Test
+    public void testDescendOfSpecialItem() throws IOException {
+      final SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+
+      compareOrRerecordTrace(
+        instance,
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Descend",
+          "SpecialItem",
+          "maximal.json.trace"));
+    } // public void testDescendOfSpecialItem
+
+    @Test
+    public void testDescendAgainstVisitorThroughForSpecialItem() throws IOException {
+      SpecialItem instance = (
+        CommonJsonization.loadMaximalSpecialItem());
+
+      assertDescendAndVisitorThroughSame(instance);
+    } // public void testDescendAgainstVisitorThroughForSpecialItem
+
+    @Test
+    public void testDescendOfContainer() throws IOException {
+      final Container instance = CommonJsonization.loadMaximalContainer();
+
+      compareOrRerecordTrace(
+        instance,
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Descend",
+          "Container",
+          "maximal.json.trace"));
+    } // public void testDescendOfContainer
+
+    @Test
+    public void testDescendAgainstVisitorThroughForContainer() throws IOException {
+      Container instance = (
+        CommonJsonization.loadMaximalContainer());
+
+      assertDescendAndVisitorThroughSame(instance);
+    } // public void testDescendAgainstVisitorThroughForContainer
+
+    @Test
+    public void testDescendOfWrapper() throws IOException {
+      final Wrapper instance = CommonJsonization.loadMaximalWrapper();
+
+      compareOrRerecordTrace(
+        instance,
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Descend",
+          "Wrapper",
+          "maximal.json.trace"));
+    } // public void testDescendOfWrapper
+
+    @Test
+    public void testDescendAgainstVisitorThroughForWrapper() throws IOException {
+      Wrapper instance = (
+        CommonJsonization.loadMaximalWrapper());
+
+      assertDescendAndVisitorThroughSame(instance);
+    } // public void testDescendAgainstVisitorThroughForWrapper
+} // class TestDescendAndVisitorThrough
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendOnce.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendOnce.java
new file mode 100644
index 000000000..61050fc5a
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestDescendOnce.java
@@ -0,0 +1,105 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.types.impl.*;
+import dummy.types.model.IClass;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+
+public class TestDescendOnce {
+  private static void compareOrRerecordTrace(IClass instance, Path expectedPath)
+    throws IOException, FileNotFoundException {
+    final StringBuilder stringBuilder = new StringBuilder();
+    for (IClass descendant : instance.descendOnce()) {
+      stringBuilder.append(Common.trace(descendant));
+    }
+
+    final String got = stringBuilder.toString();
+
+    if (Common.RECORD_MODE) {
+      Files.createDirectories(expectedPath.getParent());
+      Files.write(expectedPath, got.getBytes());
+    } else {
+      if (!Files.exists(expectedPath)) {
+        throw new FileNotFoundException(
+          "The file with the recorded trace does not exist: "
+            + expectedPath
+            + "; maybe you want to set the environment variable "
+            + Common.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME);
+      }
+      final String expected =
+        Files.readAllLines(expectedPath).stream().collect(Collectors.joining("\n"));
+      assertEquals(expected.replace("\n", ""), got.replace("\n", ""));
+    }
+  }
+
+  @Test
+  public void testSomeItem() throws IOException {
+    SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+
+    compareOrRerecordTrace(
+      instance,
+      Paths.get(
+        Common.TEST_DATA_DIR,
+        "DescendOnce",
+        "SomeItem",
+        "maximal.json.trace"));
+  } // public void testSomeItem
+
+  @Test
+  public void testSpecialItem() throws IOException {
+    SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+
+    compareOrRerecordTrace(
+      instance,
+      Paths.get(
+        Common.TEST_DATA_DIR,
+        "DescendOnce",
+        "SpecialItem",
+        "maximal.json.trace"));
+  } // public void testSpecialItem
+
+  @Test
+  public void testContainer() throws IOException {
+    Container instance = CommonJsonization.loadMaximalContainer();
+
+    compareOrRerecordTrace(
+      instance,
+      Paths.get(
+        Common.TEST_DATA_DIR,
+        "DescendOnce",
+        "Container",
+        "maximal.json.trace"));
+  } // public void testContainer
+
+  @Test
+  public void testWrapper() throws IOException {
+    Wrapper instance = CommonJsonization.loadMaximalWrapper();
+
+    compareOrRerecordTrace(
+      instance,
+      Paths.get(
+        Common.TEST_DATA_DIR,
+        "DescendOnce",
+        "Wrapper",
+        "maximal.json.trace"));
+  } // public void testWrapper
+}  // class TestDescendOnce
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestEnhancing.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestEnhancing.java
new file mode 100644
index 000000000..f46a6d794
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestEnhancing.java
@@ -0,0 +1,169 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import dummy.enhancing.Enhancer;
+import dummy.types.impl.*;
+import dummy.types.model.IClass;
+import java.io.IOException;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Function;
+import org.junit.jupiter.api.Test;
+
+public class TestEnhancing {
+  public static class _Enhancement {
+    public final long someCustomId;
+
+    public _Enhancement(long someCustomId) {
+      this.someCustomId = someCustomId;
+    }
+  }
+
+  private Enhancer<_Enhancement> createEnhancer() {
+    AtomicLong lastCustomId = new AtomicLong();
+
+    Function<IClass, Optional<_Enhancement>> enhancementFactory =
+      iClass -> Optional.of(new _Enhancement(lastCustomId.incrementAndGet()));
+
+    return new Enhancer<>(enhancementFactory);
+  }
+
+  @Test
+  public void testSomeItem() throws IOException {
+    final SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+
+    final Enhancer<_Enhancement> enhancer = createEnhancer();
+
+    assert !enhancer.unwrap(instance).isPresent();
+
+    final IClass wrapped = enhancer.wrap(instance);
+    assertNotNull(wrapped);
+
+    final Set<Long> idSet = new HashSet<>();
+    idSet.add(enhancer.mustUnwrap(wrapped).someCustomId);
+    wrapped
+      .descend()
+      .forEach(descendant -> idSet.add(enhancer.mustUnwrap(descendant).someCustomId));
+
+    assertFalse(enhancer.unwrap(instance).isPresent());
+    assertNotNull(wrapped);
+    assertEquals(
+      1L,
+      idSet.stream()
+        .min(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing min value for wrapped.")));
+    assertEquals(
+      idSet.size(),
+      idSet.stream()
+        .max(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing max value for wrapped.")));
+  } // public void testSomeItem
+
+  @Test
+  public void testSpecialItem() throws IOException {
+    final SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+
+    final Enhancer<_Enhancement> enhancer = createEnhancer();
+
+    assert !enhancer.unwrap(instance).isPresent();
+
+    final IClass wrapped = enhancer.wrap(instance);
+    assertNotNull(wrapped);
+
+    final Set<Long> idSet = new HashSet<>();
+    idSet.add(enhancer.mustUnwrap(wrapped).someCustomId);
+    wrapped
+      .descend()
+      .forEach(descendant -> idSet.add(enhancer.mustUnwrap(descendant).someCustomId));
+
+    assertFalse(enhancer.unwrap(instance).isPresent());
+    assertNotNull(wrapped);
+    assertEquals(
+      1L,
+      idSet.stream()
+        .min(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing min value for wrapped.")));
+    assertEquals(
+      idSet.size(),
+      idSet.stream()
+        .max(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing max value for wrapped.")));
+  } // public void testSpecialItem
+
+  @Test
+  public void testContainer() throws IOException {
+    final Container instance = CommonJsonization.loadMaximalContainer();
+
+    final Enhancer<_Enhancement> enhancer = createEnhancer();
+
+    assert !enhancer.unwrap(instance).isPresent();
+
+    final IClass wrapped = enhancer.wrap(instance);
+    assertNotNull(wrapped);
+
+    final Set<Long> idSet = new HashSet<>();
+    idSet.add(enhancer.mustUnwrap(wrapped).someCustomId);
+    wrapped
+      .descend()
+      .forEach(descendant -> idSet.add(enhancer.mustUnwrap(descendant).someCustomId));
+
+    assertFalse(enhancer.unwrap(instance).isPresent());
+    assertNotNull(wrapped);
+    assertEquals(
+      1L,
+      idSet.stream()
+        .min(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing min value for wrapped.")));
+    assertEquals(
+      idSet.size(),
+      idSet.stream()
+        .max(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing max value for wrapped.")));
+  } // public void testContainer
+
+  @Test
+  public void testWrapper() throws IOException {
+    final Wrapper instance = CommonJsonization.loadMaximalWrapper();
+
+    final Enhancer<_Enhancement> enhancer = createEnhancer();
+
+    assert !enhancer.unwrap(instance).isPresent();
+
+    final IClass wrapped = enhancer.wrap(instance);
+    assertNotNull(wrapped);
+
+    final Set<Long> idSet = new HashSet<>();
+    idSet.add(enhancer.mustUnwrap(wrapped).someCustomId);
+    wrapped
+      .descend()
+      .forEach(descendant -> idSet.add(enhancer.mustUnwrap(descendant).someCustomId));
+
+    assertFalse(enhancer.unwrap(instance).isPresent());
+    assertNotNull(wrapped);
+    assertEquals(
+      1L,
+      idSet.stream()
+        .min(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing min value for wrapped.")));
+    assertEquals(
+      idSet.size(),
+      idSet.stream()
+        .max(Comparator.comparing(Long::valueOf))
+        .orElseThrow(() -> new IllegalStateException("Missing max value for wrapped.")));
+  } // public void testWrapper
+}  // class TestEnhancing
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfConcreteClasses.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfConcreteClasses.java
new file mode 100644
index 000000000..e4cdae03e
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfConcreteClasses.java
@@ -0,0 +1,527 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import dummy.jsonization.Jsonization;
+import dummy.reporting.Reporting;
+import dummy.types.impl.*;
+import dummy.types.model.IClass;
+import dummy.common.*;
+import dummy.types.enums.*;
+import dummy.types.model.*;
+import dummy.verification.Verification;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.JsonNodeFactory;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+
+public class TestJsonizationOfConcreteClasses {
+  private static void assertSerializeDeserializeEqualsOriginal(JsonNode originalNode, IClass instance, Path path)
+    throws JsonProcessingException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    JsonNode serialized = null;
+    try {
+      serialized = Jsonization.Serialize.toJsonObject(instance);
+    } catch (Exception exception) {
+      fail("Expected no exception upon serialization of an instance " +
+        "de-serialized from " + path + ", but got: " + exception);
+    }
+
+    if (serialized == null) {
+      fail(
+        "Unexpected null serialization of an instance from " + path);
+    }
+
+  assertEquals(objectMapper.readTree(originalNode.toString()), objectMapper.readTree(serialized.toString()));
+  }
+
+  private static void assertEqualsExpectedOrRerecordDeserializationException(
+    Jsonization.DeserializeException exception,
+    Path path) throws FileNotFoundException, IOException{
+    if (exception == null) {
+      fail("Expected a Jsonization exception when de-serializing " +
+      path +
+      ", but got none.");
+    } else {
+      final Path exceptionPath = Paths.get(path + ".exception");
+      final String got = exception.getMessage();
+      if (Common.RECORD_MODE) {
+        Files.write(exceptionPath, got.getBytes(StandardCharsets.UTF_8));
+      } else {
+  if (!Files.exists(exceptionPath)) {
+    throw new FileNotFoundException(
+      "The file with the recorded errors does not exist: "
+        + exceptionPath
+        + "; maybe you want to set the environment variable "
+        + Common.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME);
+  }
+  final String expected =
+    Files.readAllLines(exceptionPath).stream().collect(Collectors.joining("\n"));
+  assertEquals(
+    expected,
+    got,
+    "The expected exception does not match the actual one for the file " + path);
+      }
+    }
+  }
+
+  @Test
+  public void testSomeItemOk() throws IOException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    final Path searchPath = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SomeItem");
+    final List<Path> paths = Common.findPaths(searchPath, ".json");
+
+    for (Path path : paths) {
+      final JsonNode node = objectMapper.readTree(path.toFile());
+      final SomeItem instance = Jsonization.Deserialize.deserializeSomeItem(node);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+    }
+  } // public void testSomeItemOk
+
+  @Test
+  public void testSomeItemDeserializationFromNonObjectFail() throws IOException {
+    final JsonNode node = JsonNodeFactory.instance.textNode("INVALID");
+
+    Jsonization.DeserializeException exception = null;
+    try {
+      final SomeItem unused = Jsonization.Deserialize.deserializeSomeItem(node);
+    } catch (Jsonization.DeserializeException observedException) {
+      exception = observedException;
+    }
+
+    assert exception != null : "Expected an exception, but got none";
+    assert exception.getMessage().startsWith("Expected a JsonObject, but got ") :
+      "Unexpected exception message: " + exception.getMessage();
+  } // public void testSomeItemDeserializationFromNonObjectFail
+
+  @Test
+  public void testSomeItemDeserializationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir = causeDir.resolve("SomeItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SomeItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        Jsonization.DeserializeException exception = null;
+        try {
+          final SomeItem var = Jsonization.Deserialize.deserializeSomeItem(node);
+        } catch (Jsonization.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(
+          exception, path);
+      }
+    }
+  } // public void testSomeItemDeserializationFail
+
+  @Test
+  public void testSomeItemVerificationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve("SomeItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SomeItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        final SomeItem instance = Jsonization.Deserialize.deserializeSomeItem(node);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testSomeItemVerificationFail
+
+  @Test
+  public void testSpecialItemOk() throws IOException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    final Path searchPath = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "SpecialItem");
+    final List<Path> paths = Common.findPaths(searchPath, ".json");
+
+    for (Path path : paths) {
+      final JsonNode node = objectMapper.readTree(path.toFile());
+      final SpecialItem instance = Jsonization.Deserialize.deserializeSpecialItem(node);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+    }
+  } // public void testSpecialItemOk
+
+  @Test
+  public void testSpecialItemDeserializationFromNonObjectFail() throws IOException {
+    final JsonNode node = JsonNodeFactory.instance.textNode("INVALID");
+
+    Jsonization.DeserializeException exception = null;
+    try {
+      final SpecialItem unused = Jsonization.Deserialize.deserializeSpecialItem(node);
+    } catch (Jsonization.DeserializeException observedException) {
+      exception = observedException;
+    }
+
+    assert exception != null : "Expected an exception, but got none";
+    assert exception.getMessage().startsWith("Expected a JsonObject, but got ") :
+      "Unexpected exception message: " + exception.getMessage();
+  } // public void testSpecialItemDeserializationFromNonObjectFail
+
+  @Test
+  public void testSpecialItemDeserializationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir = causeDir.resolve("SpecialItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SpecialItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        Jsonization.DeserializeException exception = null;
+        try {
+          final SpecialItem var = Jsonization.Deserialize.deserializeSpecialItem(node);
+        } catch (Jsonization.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(
+          exception, path);
+      }
+    }
+  } // public void testSpecialItemDeserializationFail
+
+  @Test
+  public void testSpecialItemVerificationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve("SpecialItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SpecialItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        final SpecialItem instance = Jsonization.Deserialize.deserializeSpecialItem(node);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testSpecialItemVerificationFail
+
+  @Test
+  public void testContainerOk() throws IOException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    final Path searchPath = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Container");
+    final List<Path> paths = Common.findPaths(searchPath, ".json");
+
+    for (Path path : paths) {
+      final JsonNode node = objectMapper.readTree(path.toFile());
+      final Container instance = Jsonization.Deserialize.deserializeContainer(node);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+    }
+  } // public void testContainerOk
+
+  @Test
+  public void testContainerDeserializationFromNonObjectFail() throws IOException {
+    final JsonNode node = JsonNodeFactory.instance.textNode("INVALID");
+
+    Jsonization.DeserializeException exception = null;
+    try {
+      final Container unused = Jsonization.Deserialize.deserializeContainer(node);
+    } catch (Jsonization.DeserializeException observedException) {
+      exception = observedException;
+    }
+
+    assert exception != null : "Expected an exception, but got none";
+    assert exception.getMessage().startsWith("Expected a JsonObject, but got ") :
+      "Unexpected exception message: " + exception.getMessage();
+  } // public void testContainerDeserializationFromNonObjectFail
+
+  @Test
+  public void testContainerDeserializationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir = causeDir.resolve("Container");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Container for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        Jsonization.DeserializeException exception = null;
+        try {
+          final Container var = Jsonization.Deserialize.deserializeContainer(node);
+        } catch (Jsonization.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(
+          exception, path);
+      }
+    }
+  } // public void testContainerDeserializationFail
+
+  @Test
+  public void testContainerVerificationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve("Container");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Container for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        final Container instance = Jsonization.Deserialize.deserializeContainer(node);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testContainerVerificationFail
+
+  @Test
+  public void testWrapperOk() throws IOException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    final Path searchPath = Paths.get(
+      Common.TEST_DATA_DIR,
+      "Json",
+      "Expected",
+      "Wrapper");
+    final List<Path> paths = Common.findPaths(searchPath, ".json");
+
+    for (Path path : paths) {
+      final JsonNode node = objectMapper.readTree(path.toFile());
+      final Wrapper instance = Jsonization.Deserialize.deserializeWrapper(node);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+    }
+  } // public void testWrapperOk
+
+  @Test
+  public void testWrapperDeserializationFromNonObjectFail() throws IOException {
+    final JsonNode node = JsonNodeFactory.instance.textNode("INVALID");
+
+    Jsonization.DeserializeException exception = null;
+    try {
+      final Wrapper unused = Jsonization.Deserialize.deserializeWrapper(node);
+    } catch (Jsonization.DeserializeException observedException) {
+      exception = observedException;
+    }
+
+    assert exception != null : "Expected an exception, but got none";
+    assert exception.getMessage().startsWith("Expected a JsonObject, but got ") :
+      "Unexpected exception message: " + exception.getMessage();
+  } // public void testWrapperDeserializationFromNonObjectFail
+
+  @Test
+  public void testWrapperDeserializationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir = causeDir.resolve("Wrapper");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Wrapper for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        Jsonization.DeserializeException exception = null;
+        try {
+          final Wrapper var = Jsonization.Deserialize.deserializeWrapper(node);
+        } catch (Jsonization.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(
+          exception, path);
+      }
+    }
+  } // public void testWrapperDeserializationFail
+
+  @Test
+  public void testWrapperVerificationFail() throws IOException {
+    for (Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve("Wrapper");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Wrapper for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".json");
+      for (Path path : paths) {
+        final JsonNode node = CommonJson.readFromFile(path);
+
+        final Wrapper instance = Jsonization.Deserialize.deserializeWrapper(node);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testWrapperVerificationFail
+
+  private static JsonNode loadTheFirstExpected(String modelType) throws IOException {
+    final List<Path> paths =
+      Common.findPaths(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Json",
+          "Expected",
+          modelType),
+        ".json");
+
+    if (paths.isEmpty()) {
+      fail("Expected at least one recorded example of " + modelType + ", but got none");
+    }
+
+    return CommonJson.readFromFile(paths.get(0));
+  }
+
+  @Test
+  public void testSpecialItemLevelSerializationOutofrange() throws IOException {
+    for (long value : new long[] {9007199254740992L, -9007199254740992L}) {
+      final SpecialItem instance =
+        Jsonization.Deserialize.deserializeSpecialItem(
+          loadTheFirstExpected("SpecialItem"));
+
+      instance.setLevel(value);
+
+      try {
+        Jsonization.Serialize.toJsonObject(instance);
+        fail(
+          "Expected the serialization to fail at "
+            + "getLevel()"
+            + ", but it succeeded");
+      } catch (Jsonization.SerializeException exception) {
+        assertEquals(
+          "getLevel()",
+          exception.getPath().orElse(null));
+      }
+    }
+  } // public void testSpecialItemLevelSerializationOutofrange
+} // class TestJsonizationOfConcreteClasses
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfEnums.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfEnums.java
new file mode 100644
index 000000000..28eb2f4ae
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfEnums.java
@@ -0,0 +1,25 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.jsonization.Jsonization;
+import dummy.types.enums.*;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.JsonNodeFactory;
+import org.junit.jupiter.api.Test;
+
+public class TestJsonizationOfEnums {
+  
+} // class TestJsonizationOfEnums
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfInterfaces.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfInterfaces.java
new file mode 100644
index 000000000..a91cc73d0
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestJsonizationOfInterfaces.java
@@ -0,0 +1,91 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.jsonization.Jsonization;
+import dummy.reporting.*;
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+
+public class TestJsonizationOfInterfaces {
+  @Test
+  public void testRoundTripIItemFromSomeItem()
+    throws IOException, JsonProcessingException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+    final JsonNode jsonObject = Jsonization.Serialize.toJsonObject(instance);
+
+    IItem anotherInstance = Jsonization.Deserialize.deserializeIItem(
+      jsonObject);
+    final JsonNode anotherJsonObject = Jsonization.Serialize.toJsonObject(anotherInstance);
+
+    assertEquals(
+      objectMapper.readTree(jsonObject.toString()), objectMapper.readTree(anotherJsonObject.toString()));
+  } // void testRoundTripIItemFromSomeItem
+
+  @Test
+  public void testRoundTripIItemFromSpecialItem()
+    throws IOException, JsonProcessingException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+    final JsonNode jsonObject = Jsonization.Serialize.toJsonObject(instance);
+
+    IItem anotherInstance = Jsonization.Deserialize.deserializeIItem(
+      jsonObject);
+    final JsonNode anotherJsonObject = Jsonization.Serialize.toJsonObject(anotherInstance);
+
+    assertEquals(
+      objectMapper.readTree(jsonObject.toString()), objectMapper.readTree(anotherJsonObject.toString()));
+  } // void testRoundTripIItemFromSpecialItem
+
+  @Test
+  public void testRoundTripISomeItemFromSpecialItem()
+    throws IOException, JsonProcessingException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    SpecialItem instance = CommonJsonization.loadMaximalSpecialItem();
+    final JsonNode jsonObject = Jsonization.Serialize.toJsonObject(instance);
+
+    ISomeItem anotherInstance = Jsonization.Deserialize.deserializeISomeItem(
+      jsonObject);
+    final JsonNode anotherJsonObject = Jsonization.Serialize.toJsonObject(anotherInstance);
+
+    assertEquals(
+      objectMapper.readTree(jsonObject.toString()), objectMapper.readTree(anotherJsonObject.toString()));
+  } // void testRoundTripISomeItemFromSpecialItem
+
+  @Test
+  public void testRoundTripISomeItemFromSomeItem()
+    throws IOException, JsonProcessingException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+
+    SomeItem instance = CommonJsonization.loadMaximalSomeItem();
+    final JsonNode jsonObject = Jsonization.Serialize.toJsonObject(instance);
+
+    ISomeItem anotherInstance = Jsonization.Deserialize.deserializeISomeItem(
+      jsonObject);
+    final JsonNode anotherJsonObject = Jsonization.Serialize.toJsonObject(anotherInstance);
+
+    assertEquals(
+      objectMapper.readTree(jsonObject.toString()), objectMapper.readTree(anotherJsonObject.toString()));
+  } // void testRoundTripISomeItemFromSomeItem
+} // class TestJsonizationOfInterfaces
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestOverXOrEmpty.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestOverXOrEmpty.java
new file mode 100644
index 000000000..b30a97f2d
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestOverXOrEmpty.java
@@ -0,0 +1,37 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.junit.jupiter.api.Test;
+
+public class TestOverXOrEmpty {
+  @Test
+  public void testContainerOverSpecialItemsOrEmpty() throws IOException {
+    for (Container instance : new Container[]
+    {
+      CommonJsonization.loadMinimalContainer(),
+      CommonJsonization.loadMaximalContainer()
+    }) {
+      int length = instance.getSpecialItems().map(elem -> elem.size()).orElse(0);
+      AtomicInteger count = new AtomicInteger();
+      instance.overSpecialItemsOrEmpty().forEach(i -> count.getAndIncrement());
+      assertEquals(length , count.get());
+    }
+  } // public void testContaineroverSpecialItemsOrEmpty
+} // class TestOverXOrEmpty
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestStringHelpers.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestStringHelpers.java
new file mode 100644
index 000000000..d4a31f9f9
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestStringHelpers.java
@@ -0,0 +1,364 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.common.StringHelpers;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test {@code len}, the slicing of strings and {@code find} as used in
+ * the transpiled code.
+ *
+ * <p>The transpiled code follows the Python implementation, since Python is
+ * the language of the meta-model specifications. Hence, the lengths and
+ * the positions count the characters (code points). The expected values have
+ * been computed with Python, and all the SDKs test against the very same cases.
+ */
+public class TestStringHelpers {
+  @Test
+  @DisplayName("len(\'\') gives 0: empty text")
+  public void testLenEmptyText() {
+    assertEquals(
+      0,
+      StringHelpers.len(""));
+  }
+
+  @Test
+  @DisplayName("len(\'abc\') gives 3: ASCII text")
+  public void testLenAsciiText() {
+    assertEquals(
+      3,
+      StringHelpers.len("abc"));
+  }
+
+  @Test
+  @DisplayName("len(\'é-\') gives 2: character of two UTF-8 bytes")
+  public void testLenCharacterOfTwoUtf8Bytes() {
+    assertEquals(
+      2,
+      StringHelpers.len("é-"));
+  }
+
+  @Test
+  @DisplayName("len(\'😀-\') gives 2: character beyond the Basic Multilingual Plane")
+  public void testLenCharacterBeyondTheBasicMultilingualPlane() {
+    assertEquals(
+      2,
+      StringHelpers.len("😀-"));
+  }
+
+  @Test
+  @DisplayName("len(\'aé😀b😀\') gives 5: mixed characters")
+  public void testLenMixedCharacters() {
+    assertEquals(
+      5,
+      StringHelpers.len("aé😀b😀"));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[1:3] gives \'bc\': start and end")
+  public void testSliceStartAndEnd() {
+    assertEquals(
+      "bc",
+      StringHelpers.slice("abcde", 1, 3));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[:2] gives \'ab\': no start")
+  public void testSliceNoStart() {
+    assertEquals(
+      "ab",
+      StringHelpers.slice("abcde", 0, 2));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[3:] gives \'de\': no end")
+  public void testSliceNoEnd() {
+    assertEquals(
+      "de",
+      StringHelpers.slice("abcde", 3));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[:] gives \'abcde\': neither start nor end")
+  public void testSliceNeitherStartNorEnd() {
+    assertEquals(
+      "abcde",
+      StringHelpers.slice("abcde", 0));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[-2:] gives \'de\': negative start counts from the end")
+  public void testSliceNegativeStartCountsFromTheEnd() {
+    assertEquals(
+      "de",
+      StringHelpers.slice("abcde", -2));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[:-2] gives \'abc\': negative end counts from the end")
+  public void testSliceNegativeEndCountsFromTheEnd() {
+    assertEquals(
+      "abc",
+      StringHelpers.slice("abcde", 0, -2));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[-4:-1] gives \'bcd\': negative start and end")
+  public void testSliceNegativeStartAndEnd() {
+    assertEquals(
+      "bcd",
+      StringHelpers.slice("abcde", -4, -1));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[-10:2] gives \'ab\': negative start before the beginning is clamped")
+  public void testSliceNegativeStartBeforeTheBeginningIsClamped() {
+    assertEquals(
+      "ab",
+      StringHelpers.slice("abcde", -10, 2));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[2:10] gives \'cde\': end beyond the end is clamped")
+  public void testSliceEndBeyondTheEndIsClamped() {
+    assertEquals(
+      "cde",
+      StringHelpers.slice("abcde", 2, 10));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[10:] gives \'\': start beyond the end gives empty")
+  public void testSliceStartBeyondTheEndGivesEmpty() {
+    assertEquals(
+      "",
+      StringHelpers.slice("abcde", 10));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[3:1] gives \'\': start after end gives empty")
+  public void testSliceStartAfterEndGivesEmpty() {
+    assertEquals(
+      "",
+      StringHelpers.slice("abcde", 3, 1));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[-1:-3] gives \'\': negative start after negative end gives empty")
+  public void testSliceNegativeStartAfterNegativeEndGivesEmpty() {
+    assertEquals(
+      "",
+      StringHelpers.slice("abcde", -1, -3));
+  }
+
+  @Test
+  @DisplayName("\'abcde\'[5:5] gives \'\': start equal to end gives empty")
+  public void testSliceStartEqualToEndGivesEmpty() {
+    assertEquals(
+      "",
+      StringHelpers.slice("abcde", 5, 5));
+  }
+
+  @Test
+  @DisplayName("\'\'[0:0] gives \'\': empty text")
+  public void testSliceEmptyText() {
+    assertEquals(
+      "",
+      StringHelpers.slice("", 0, 0));
+  }
+
+  @Test
+  @DisplayName("\'\'[-1:] gives \'\': negative start on empty text")
+  public void testSliceNegativeStartOnEmptyText() {
+    assertEquals(
+      "",
+      StringHelpers.slice("", -1));
+  }
+
+  @Test
+  @DisplayName("\'\'[:5] gives \'\': end beyond the end of empty text")
+  public void testSliceEndBeyondTheEndOfEmptyText() {
+    assertEquals(
+      "",
+      StringHelpers.slice("", 0, 5));
+  }
+
+  @Test
+  @DisplayName("\'é-x\'[1:] gives \'-x\': after a character of two UTF-8 bytes")
+  public void testSliceAfterACharacterOfTwoUtf8Bytes() {
+    assertEquals(
+      "-x",
+      StringHelpers.slice("é-x", 1));
+  }
+
+  @Test
+  @DisplayName("\'aéb\'[1:2] gives \'é\': character of two UTF-8 bytes")
+  public void testSliceCharacterOfTwoUtf8Bytes() {
+    assertEquals(
+      "é",
+      StringHelpers.slice("aéb", 1, 2));
+  }
+
+  @Test
+  @DisplayName("\'a😀b\'[1:2] gives \'😀\': character beyond the Basic Multilingual Plane")
+  public void testSliceCharacterBeyondTheBasicMultilingualPlane() {
+    assertEquals(
+      "😀",
+      StringHelpers.slice("a😀b", 1, 2));
+  }
+
+  @Test
+  @DisplayName("\'😀-x\'[1:] gives \'-x\': after a character beyond the Basic Multilingual Plane")
+  public void testSliceAfterACharacterBeyondTheBasicMultilingualPlane() {
+    assertEquals(
+      "-x",
+      StringHelpers.slice("😀-x", 1));
+  }
+
+  @Test
+  @DisplayName("\'aé😀b😀\'[-3:-1] gives \'😀b\': negative start on characters beyond ASCII")
+  public void testSliceNegativeStartOnCharactersBeyondAscii() {
+    assertEquals(
+      "😀b",
+      StringHelpers.slice("aé😀b😀", -3, -1));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'b\') gives 1: found")
+  public void testFindFound() {
+    assertEquals(1, StringHelpers.find("abcabc", "b"));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'x\') gives -1: not found")
+  public void testFindNotFound() {
+    assertEquals(-1, StringHelpers.find("abcabc", "x"));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'\') gives 0: empty sub")
+  public void testFindEmptySub() {
+    assertEquals(0, StringHelpers.find("abcabc", ""));
+  }
+
+  @Test
+  @DisplayName("\'ab\'.find(\'abc\') gives -1: sub longer than text")
+  public void testFindSubLongerThanText() {
+    assertEquals(-1, StringHelpers.find("ab", "abc"));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'b\', 2) gives 4: found after start")
+  public void testFindFoundAfterStart() {
+    assertEquals(4, StringHelpers.find("abcabc", "b", 2));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'b\', 5) gives -1: found only before start")
+  public void testFindFoundOnlyBeforeStart() {
+    assertEquals(-1, StringHelpers.find("abcabc", "b", 5));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'c\', -1) gives 5: negative start counts from the end")
+  public void testFindNegativeStartCountsFromTheEnd() {
+    assertEquals(5, StringHelpers.find("abcabc", "c", -1));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'a\', -3) gives 3: negative start finds the later occurrence")
+  public void testFindNegativeStartFindsTheLaterOccurrence() {
+    assertEquals(3, StringHelpers.find("abcabc", "a", -3));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'a\', -10) gives 0: negative start before the beginning is clamped")
+  public void testFindNegativeStartBeforeTheBeginningIsClamped() {
+    assertEquals(0, StringHelpers.find("abcabc", "a", -10));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'\', 6) gives 6: empty sub at the end")
+  public void testFindEmptySubAtTheEnd() {
+    assertEquals(6, StringHelpers.find("abcabc", "", 6));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'\', 7) gives -1: empty sub beyond the end gives -1")
+  public void testFindEmptySubBeyondTheEndGives1() {
+    assertEquals(-1, StringHelpers.find("abcabc", "", 7));
+  }
+
+  @Test
+  @DisplayName("\'abcabc\'.find(\'c\', 10) gives -1: start beyond the end gives -1")
+  public void testFindStartBeyondTheEndGives1() {
+    assertEquals(-1, StringHelpers.find("abcabc", "c", 10));
+  }
+
+  @Test
+  @DisplayName("\'\'.find(\'\') gives 0: empty sub in empty text")
+  public void testFindEmptySubInEmptyText() {
+    assertEquals(0, StringHelpers.find("", ""));
+  }
+
+  @Test
+  @DisplayName("\'\'.find(\'\', 1) gives -1: empty sub beyond the end of empty text gives -1")
+  public void testFindEmptySubBeyondTheEndOfEmptyTextGives1() {
+    assertEquals(-1, StringHelpers.find("", "", 1));
+  }
+
+  @Test
+  @DisplayName("\'\'.find(\'x\') gives -1: not found in empty text")
+  public void testFindNotFoundInEmptyText() {
+    assertEquals(-1, StringHelpers.find("", "x"));
+  }
+
+  @Test
+  @DisplayName("\'é-\'.find(\'-\') gives 1: after a character of two UTF-8 bytes")
+  public void testFindAfterACharacterOfTwoUtf8Bytes() {
+    assertEquals(1, StringHelpers.find("é-", "-"));
+  }
+
+  @Test
+  @DisplayName("\'😀-\'.find(\'-\') gives 1: after a character beyond the Basic Multilingual Plane")
+  public void testFindAfterACharacterBeyondTheBasicMultilingualPlane() {
+    assertEquals(1, StringHelpers.find("😀-", "-"));
+  }
+
+  @Test
+  @DisplayName("\'a😀b\'.find(\'😀\') gives 1: character beyond the Basic Multilingual Plane")
+  public void testFindCharacterBeyondTheBasicMultilingualPlane() {
+    assertEquals(1, StringHelpers.find("a😀b", "😀"));
+  }
+
+  @Test
+  @DisplayName("\'😀a😀a\'.find(\'a\', 2) gives 3: start after a character beyond ASCII")
+  public void testFindStartAfterACharacterBeyondAscii() {
+    assertEquals(3, StringHelpers.find("😀a😀a", "a", 2));
+  }
+
+  @Test
+  @DisplayName("\'😀a😀a\'.find(\'😀\', -2) gives 2: negative start on characters beyond ASCII")
+  public void testFindNegativeStartOnCharactersBeyondAscii() {
+    assertEquals(2, StringHelpers.find("😀a😀a", "😀", -2));
+  }
+
+  @Test
+  @DisplayName("\'é😀\'.find(\'\', 3) gives -1: start beyond the end of characters beyond ASCII")
+  public void testFindStartBeyondTheEndOfCharactersBeyondAscii() {
+    assertEquals(-1, StringHelpers.find("é😀", "", 3));
+  }
+} // class TestStringHelpers
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestVerificationOfEnums.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestVerificationOfEnums.java
new file mode 100644
index 000000000..7f09a60a0
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestVerificationOfEnums.java
@@ -0,0 +1,26 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.reporting.Reporting;
+import dummy.types.enums.*;
+import dummy.verification.Verification;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+
+public class TestVerificationOfEnums {
+  
+} // class TestVerificationOfEnums
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXOrDefault.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXOrDefault.java
new file mode 100644
index 000000000..fb5cac770
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXOrDefault.java
@@ -0,0 +1,53 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.reporting.*;
+import dummy.stringification.Stringification;
+import dummy.types.enums.*;
+import dummy.types.impl.*;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+import org.junit.jupiter.api.Test;
+
+public class TestXOrDefault {
+  private static void compareOrRerecordValue(Object value, Path expectedPath) throws IOException {
+    final ObjectMapper objectMapper = new ObjectMapper();
+    JsonNode got = CommonJson.toJson(value);
+
+    if (Common.RECORD_MODE) {
+      Files.createDirectories(expectedPath.getParent());
+      Files.write(expectedPath, got.toString().getBytes());
+    }
+    else
+    {
+      if (!Files.exists(expectedPath)) {
+        throw new FileNotFoundException(
+          "The file with the recorded value does not exist: " + expectedPath + "; " +
+          "maybe you want to set the environment variable " +
+          Common.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME + "?");
+      }
+
+      final JsonNode expected = objectMapper.readTree(expectedPath.toFile());
+      assertEquals(objectMapper.readTree(expected.toString()), objectMapper.readTree(got.toString()));
+    }
+  }
+} // class TestXOrDefault
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfConcreteClasses.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfConcreteClasses.java
new file mode 100644
index 000000000..618a5b50c
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfConcreteClasses.java
@@ -0,0 +1,647 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import dummy.reporting.Reporting;
+import dummy.types.impl.*;
+import dummy.types.model.IClass;
+import dummy.verification.Verification;
+import dummy.xmlcommon.XmlCommon;
+import dummy.xmlization.Xmlization;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import javax.xml.stream.*;
+import javax.xml.stream.events.XMLEvent;
+import org.junit.jupiter.api.Test;
+
+public class TestXmlizationOfConcreteClasses {
+  public static Optional<Reporting.Error> checkElementsEqual(
+    XMLEvent expected, String expectedContent, Map<XMLEvent, String> outputMap) {
+    switch (expected.getEventType()) {
+      case XMLStreamConstants.START_ELEMENT:
+        {
+          final String expectedName = expected.asStartElement().getName().getLocalPart();
+          final Optional<Map.Entry<XMLEvent, String>> got =
+            outputMap.entrySet().stream()
+              .filter(
+                entry ->
+                  entry.getKey().isStartElement()
+                    && entry
+                      .getKey()
+                      .asStartElement()
+                      .getName()
+                      .getLocalPart()
+                      .equals(expectedName))
+              .filter(entry -> entry.getValue().equals(expectedContent))
+                .findAny();
+          if (!got.isPresent()) {
+            final Reporting.Error error =
+              new Reporting.Error(
+                "Missing start element "
+                  + expectedName
+                  + " in with content: "
+                  + expectedContent);
+            return Optional.of(error);
+          }
+          outputMap.remove(got.get().getKey());
+          return Optional.empty();
+        }
+      case XMLStreamConstants.END_ELEMENT:
+        {
+          final String expectedName = expected.asEndElement().getName().getLocalPart();
+          final Optional<Map.Entry<XMLEvent, String>> got =
+            outputMap.entrySet().stream()
+              .filter(
+                entry ->
+                  entry.getKey().isEndElement()
+                    && entry
+                      .getKey()
+                      .asEndElement()
+                      .getName()
+                      .getLocalPart()
+                      .equals(expectedName))
+              .findAny();
+          if (!got.isPresent()) {
+            final Reporting.Error error =
+              new Reporting.Error("Missing end element " + expectedName);
+            return Optional.of(error);
+          }
+          outputMap.remove(got.get().getKey());
+          return Optional.empty();
+        }
+      default:
+        {
+          throw new IllegalStateException("Unexpected event type in check elements equal.");
+        }
+    }
+  }
+
+  private static String readContent(XMLEventReader reader) throws XMLStreamException {
+    final StringBuilder content = new StringBuilder();
+    while (reader.hasNext() && reader.peek().isCharacters()
+        && !reader.peek().asCharacters().isWhiteSpace()
+        || reader.peek().getEventType() == XMLStreamConstants.COMMENT) {
+
+      if (reader.peek().isCharacters()) {
+        content.append(reader.peek().asCharacters().getData());
+      }
+      reader.nextEvent();
+    }
+    return content.toString();
+  }
+
+  private static Map<XMLEvent, String> buildElementsMap(XMLEventReader reader) throws XMLStreamException {
+    final Map<XMLEvent, String> result = new LinkedHashMap<>();
+    while (reader.hasNext()) {
+      final XMLEvent current = reader.nextEvent();
+      if (current.isStartElement()) {
+        result.put(current, readContent(reader));
+      } else if (current.isEndElement()) {
+        result.put(current, "");
+      }
+    }
+    return result;
+  }
+
+  private static void assertSerializeDeserializeEqualsOriginal(IClass instance, Path path)
+    throws XMLStreamException, IOException {
+    // Serialize
+    final StringWriter stringOut = new StringWriter();
+    final XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
+    final XMLStreamWriter xmlStreamWriter = outputFactory.createXMLStreamWriter(stringOut);
+
+    Xmlization.Serialize.to(instance, xmlStreamWriter);
+
+    final String outputText = stringOut.toString();
+
+  // Compare expected == output
+  final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+  final XMLEventReader outputReader =
+    xmlInputFactory.createXMLEventReader(new StringReader(outputText));
+  final Map<XMLEvent, String> outputMap = buildElementsMap(outputReader);
+
+  // check the namespace of the output
+  for (XMLEvent event : outputMap.keySet()) {
+    if (event.isStartElement()) {
+      assertTrue(
+        Xmlization.NAMESPACE.equals(event.asStartElement().getName().getNamespaceURI()),
+        "Unexpected namespace of " + event.asStartElement().getName());
+    }
+    if (event.isEndElement()) {
+      assertTrue(
+        Xmlization.NAMESPACE.equals(event.asEndElement().getName().getNamespaceURI()),
+        "Unexpected namespace of " + event.asEndElement().getName());
+    }
+  }
+
+  final XMLEventReader expectedReader =
+    xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+  final Map<XMLEvent, String> expectedMap = buildElementsMap(expectedReader);
+
+  if (expectedMap.size() != outputMap.size()) {
+    fail(
+      "Mismatch in element size expected "
+        + expectedMap.size()
+        + " but got "
+        + outputMap.size());
+  }
+
+  expectedMap.forEach(
+    (xmlEvent, content) -> {
+      final Optional<Reporting.Error> inequalityError =
+          checkElementsEqual(xmlEvent, content, outputMap);
+      inequalityError.ifPresent(
+        error ->
+          fail(
+            "The original XML from "
+               + path
+               + " is unequal the serialized XML: "
+               + error.getCause()));
+    });
+  }
+
+  private static void assertEqualsExpectedOrRerecordDeserializationException(
+    XmlCommon.DeserializeException exception,
+    Path path) throws IOException {
+    if (exception == null) {
+      fail("Expected a Xmlization exception when de-serializing " + path + ", but got none.");
+    } else {
+      final Path exceptionPath = Paths.get(path + ".exception");
+      final String got = exception.getMessage();
+      if (Common.RECORD_MODE) {
+        Files.write(exceptionPath, got.getBytes(StandardCharsets.UTF_8));
+      } else {
+        if (!Files.exists(exceptionPath)) {
+          throw new FileNotFoundException(
+            "The file with the recorded exception does not exist: "
+            + exceptionPath
+            + "; maybe you want to set the environment variable"
+            + Common.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME
+            + "?");
+        }
+
+        final String expected = String.join("\n", Files.readAllLines(exceptionPath));
+        assertEquals(
+          expected.replace("\n", ""),
+          got.replace("\n", ""),
+          "The expected exception does not match the actual one for the file " + path);
+      }
+    }
+  }
+
+  @Test
+  public void testSomeItemOk() throws IOException, XMLStreamException {
+    final Path searchPath =
+      Paths.get(Common.TEST_DATA_DIR, "Xml", "Expected", "someItem");
+    final List<Path> paths = Common.findPaths(searchPath, ".xml");
+
+    for (Path path : paths) {
+      final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+      final XMLEventReader xmlReader =
+        xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+      final SomeItem instance =
+        Xmlization.Deserialize.deserializeSomeItem(xmlReader);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+
+      assertSerializeDeserializeEqualsOriginal(instance, path);
+    }
+  } // public void testSomeItemOk
+
+  @Test
+  public void testSomeItemDeserializationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir =
+        causeDir.resolve("someItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SomeItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        XmlCommon.DeserializeException exception = null;
+
+        try {
+          Xmlization.Deserialize.deserializeSomeItem(xmlReader);
+        } catch (XmlCommon.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(exception, path);
+      }
+    }
+  }  // public void testSomeItemDeserializationFail
+
+  @Test
+  public void testSomeItemVerificationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve(
+        "someItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SomeItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        final SomeItem instance =
+          Xmlization.Deserialize.deserializeSomeItem(xmlReader);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testSomeItemVerificationFail
+
+  @Test
+  public void testSpecialItemOk() throws IOException, XMLStreamException {
+    final Path searchPath =
+      Paths.get(Common.TEST_DATA_DIR, "Xml", "Expected", "specialItem");
+    final List<Path> paths = Common.findPaths(searchPath, ".xml");
+
+    for (Path path : paths) {
+      final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+      final XMLEventReader xmlReader =
+        xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+      final SpecialItem instance =
+        Xmlization.Deserialize.deserializeSpecialItem(xmlReader);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+
+      assertSerializeDeserializeEqualsOriginal(instance, path);
+    }
+  } // public void testSpecialItemOk
+
+  @Test
+  public void testSpecialItemDeserializationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir =
+        causeDir.resolve("specialItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SpecialItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        XmlCommon.DeserializeException exception = null;
+
+        try {
+          Xmlization.Deserialize.deserializeSpecialItem(xmlReader);
+        } catch (XmlCommon.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(exception, path);
+      }
+    }
+  }  // public void testSpecialItemDeserializationFail
+
+  @Test
+  public void testSpecialItemVerificationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve(
+        "specialItem");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of SpecialItem for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        final SpecialItem instance =
+          Xmlization.Deserialize.deserializeSpecialItem(xmlReader);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testSpecialItemVerificationFail
+
+  @Test
+  public void testContainerOk() throws IOException, XMLStreamException {
+    final Path searchPath =
+      Paths.get(Common.TEST_DATA_DIR, "Xml", "Expected", "container");
+    final List<Path> paths = Common.findPaths(searchPath, ".xml");
+
+    for (Path path : paths) {
+      final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+      final XMLEventReader xmlReader =
+        xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+      final Container instance =
+        Xmlization.Deserialize.deserializeContainer(xmlReader);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+
+      assertSerializeDeserializeEqualsOriginal(instance, path);
+    }
+  } // public void testContainerOk
+
+  @Test
+  public void testContainerDeserializationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir =
+        causeDir.resolve("container");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Container for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        XmlCommon.DeserializeException exception = null;
+
+        try {
+          Xmlization.Deserialize.deserializeContainer(xmlReader);
+        } catch (XmlCommon.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(exception, path);
+      }
+    }
+  }  // public void testContainerDeserializationFail
+
+  @Test
+  public void testContainerVerificationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve(
+        "container");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Container for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        final Container instance =
+          Xmlization.Deserialize.deserializeContainer(xmlReader);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testContainerVerificationFail
+
+  @Test
+  public void testWrapperOk() throws IOException, XMLStreamException {
+    final Path searchPath =
+      Paths.get(Common.TEST_DATA_DIR, "Xml", "Expected", "wrapper");
+    final List<Path> paths = Common.findPaths(searchPath, ".xml");
+
+    for (Path path : paths) {
+      final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+      final XMLEventReader xmlReader =
+        xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+      final Wrapper instance =
+        Xmlization.Deserialize.deserializeWrapper(xmlReader);
+
+      final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+      final List<Reporting.Error> errors = Common.asList(errorIter);
+      Common.assertNoVerificationErrors(errors, path);
+
+      assertSerializeDeserializeEqualsOriginal(instance, path);
+    }
+  } // public void testWrapperOk
+
+  @Test
+  public void testWrapperDeserializationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Unserializable"))) {
+      final Path clsDir =
+        causeDir.resolve("wrapper");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Wrapper for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        XmlCommon.DeserializeException exception = null;
+
+        try {
+          Xmlization.Deserialize.deserializeWrapper(xmlReader);
+        } catch (XmlCommon.DeserializeException observedException) {
+          exception = observedException;
+        }
+
+        assertEqualsExpectedOrRerecordDeserializationException(exception, path);
+      }
+    }
+  }  // public void testWrapperDeserializationFail
+
+  @Test
+  public void testWrapperVerificationFail() throws IOException, XMLStreamException {
+    for (
+      Path causeDir :
+      Common.findDirs(
+        Paths.get(
+          Common.TEST_DATA_DIR,
+          "Xml",
+          "Unexpected",
+          "Invalid"))) {
+      final Path clsDir = causeDir.resolve(
+        "wrapper");
+
+      if (!Files.exists(clsDir)) {
+        // No examples of Wrapper for the failure cause.
+        continue;
+      }
+
+      final List<Path> paths = Common.findPaths(clsDir, ".xml");
+      for (Path path : paths) {
+        final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+        final XMLEventReader xmlReader =
+          xmlInputFactory.createXMLEventReader(Files.newInputStream(path));
+
+        final Wrapper instance =
+          Xmlization.Deserialize.deserializeWrapper(xmlReader);
+
+        final Iterable<Reporting.Error> errorIter = Verification.verify(instance);
+        final List<Reporting.Error> errors = Common.asList(errorIter);
+        Common.assertEqualsExpectedOrRerecordVerificationErrors(errors, path);
+      }
+    }
+  } // public void testWrapperVerificationFail
+
+  @Test
+  public void testDuplicatePropertyFails() throws IOException, XMLStreamException {
+    final Path path =
+      Paths.get(
+        Common.TEST_DATA_DIR,
+        "Xml",
+        "Expected",
+        "someItem",
+        "minimal.xml");
+
+    final String text =
+      new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
+
+    // We cut the element of the property out of the recorded example and put it
+    // in a second time, just before the closing tag of the instance.
+    final int start = text.indexOf("<name>");
+
+    final String property;
+    if (start >= 0) {
+      final int end = text.indexOf("</name>", start);
+      property = text.substring(start, end + 7);
+    } else {
+      // The element is written self-closing in the example, an empty list being
+      // the usual reason. We write that very element out ourselves.
+      property = "<name/>";
+    }
+
+    final int insertionIndex =
+      text.lastIndexOf("</someItem>");
+
+    if (insertionIndex < 0) {
+      throw new IllegalStateException(
+        "We expect the recorded example to contain the closing tag "
+          + "</someItem>" + ", but it does not: " + path);
+    }
+
+    final String brokenText =
+      text.substring(0, insertionIndex) + property + text.substring(insertionIndex);
+
+    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+    final XMLEventReader xmlReader =
+      xmlInputFactory.createXMLEventReader(new StringReader(brokenText));
+
+    XmlCommon.DeserializeException exception = null;
+
+    try {
+      Xmlization.Deserialize.deserializeSomeItem(xmlReader);
+    } catch (XmlCommon.DeserializeException observedException) {
+      exception = observedException;
+    }
+
+    if (exception == null) {
+      fail(
+        "Expected an exception when the property "
+          + "name"
+          + " is given twice, but got none");
+    }
+  } // public void testDuplicatePropertyFails
+} // class TestXmlizationOfConcreteClasses
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfInterfaces.java b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfInterfaces.java
new file mode 100644
index 000000000..14b318f2f
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/src/test/java/TestXmlizationOfInterfaces.java
@@ -0,0 +1,154 @@
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
+
+package dummy.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dummy.types.impl.*;
+import dummy.types.model.*;
+import dummy.xmlization.Xmlization;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import javax.xml.stream.*;
+import org.junit.jupiter.api.Test;
+
+public class TestXmlizationOfInterfaces {
+  @Test
+  public void testRoundTripIItemFromSomeItem()
+    throws IOException, XMLStreamException {
+    // We load from JSON here just to jump-start the round trip.
+    // The round-trip goes then over XML.
+    final IItem instance =
+      CommonJsonization.loadMaximalSomeItem();
+
+    // The round-trip starts here.
+    final StringWriter stringOut = new StringWriter();
+    final XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
+    final XMLStreamWriter xmlWriter = outputFactory.createXMLStreamWriter(stringOut);
+
+    Xmlization.Serialize.to(instance, xmlWriter);
+    String outputText = stringOut.toString();
+
+    // De-serialize from XML
+    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+    final XMLEventReader xmlReader =
+      xmlInputFactory.createXMLEventReader(new StringReader(outputText));
+    final IItem anotherInstance =
+      Xmlization.Deserialize.deserializeIItem(xmlReader);
+
+    // Serialize back to XML
+    final StringWriter anotherStringOut = new StringWriter();
+    final XMLStreamWriter anotherXmlWriter = outputFactory.createXMLStreamWriter(anotherStringOut);
+    Xmlization.Serialize.to(anotherInstance, anotherXmlWriter);
+
+    // Compare
+    assertEquals(outputText, anotherStringOut.toString());
+  } // void testRoundTripIItemFromSomeItem
+
+  @Test
+  public void testRoundTripIItemFromSpecialItem()
+    throws IOException, XMLStreamException {
+    // We load from JSON here just to jump-start the round trip.
+    // The round-trip goes then over XML.
+    final IItem instance =
+      CommonJsonization.loadMaximalSpecialItem();
+
+    // The round-trip starts here.
+    final StringWriter stringOut = new StringWriter();
+    final XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
+    final XMLStreamWriter xmlWriter = outputFactory.createXMLStreamWriter(stringOut);
+
+    Xmlization.Serialize.to(instance, xmlWriter);
+    String outputText = stringOut.toString();
+
+    // De-serialize from XML
+    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+    final XMLEventReader xmlReader =
+      xmlInputFactory.createXMLEventReader(new StringReader(outputText));
+    final IItem anotherInstance =
+      Xmlization.Deserialize.deserializeIItem(xmlReader);
+
+    // Serialize back to XML
+    final StringWriter anotherStringOut = new StringWriter();
+    final XMLStreamWriter anotherXmlWriter = outputFactory.createXMLStreamWriter(anotherStringOut);
+    Xmlization.Serialize.to(anotherInstance, anotherXmlWriter);
+
+    // Compare
+    assertEquals(outputText, anotherStringOut.toString());
+  } // void testRoundTripIItemFromSpecialItem
+
+  @Test
+  public void testRoundTripISomeItemFromSpecialItem()
+    throws IOException, XMLStreamException {
+    // We load from JSON here just to jump-start the round trip.
+    // The round-trip goes then over XML.
+    final ISomeItem instance =
+      CommonJsonization.loadMaximalSpecialItem();
+
+    // The round-trip starts here.
+    final StringWriter stringOut = new StringWriter();
+    final XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
+    final XMLStreamWriter xmlWriter = outputFactory.createXMLStreamWriter(stringOut);
+
+    Xmlization.Serialize.to(instance, xmlWriter);
+    String outputText = stringOut.toString();
+
+    // De-serialize from XML
+    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+    final XMLEventReader xmlReader =
+      xmlInputFactory.createXMLEventReader(new StringReader(outputText));
+    final ISomeItem anotherInstance =
+      Xmlization.Deserialize.deserializeISomeItem(xmlReader);
+
+    // Serialize back to XML
+    final StringWriter anotherStringOut = new StringWriter();
+    final XMLStreamWriter anotherXmlWriter = outputFactory.createXMLStreamWriter(anotherStringOut);
+    Xmlization.Serialize.to(anotherInstance, anotherXmlWriter);
+
+    // Compare
+    assertEquals(outputText, anotherStringOut.toString());
+  } // void testRoundTripISomeItemFromSpecialItem
+
+  @Test
+  public void testRoundTripISomeItemFromSomeItem()
+    throws IOException, XMLStreamException {
+    // We load from JSON here just to jump-start the round trip.
+    // The round-trip goes then over XML.
+    final ISomeItem instance =
+      CommonJsonization.loadMaximalSomeItem();
+
+    // The round-trip starts here.
+    final StringWriter stringOut = new StringWriter();
+    final XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
+    final XMLStreamWriter xmlWriter = outputFactory.createXMLStreamWriter(stringOut);
+
+    Xmlization.Serialize.to(instance, xmlWriter);
+    String outputText = stringOut.toString();
+
+    // De-serialize from XML
+    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
+    final XMLEventReader xmlReader =
+      xmlInputFactory.createXMLEventReader(new StringReader(outputText));
+    final ISomeItem anotherInstance =
+      Xmlization.Deserialize.deserializeISomeItem(xmlReader);
+
+    // Serialize back to XML
+    final StringWriter anotherStringOut = new StringWriter();
+    final XMLStreamWriter anotherXmlWriter = outputFactory.createXMLStreamWriter(anotherStringOut);
+    Xmlization.Serialize.to(anotherInstance, anotherXmlWriter);
+
+    // Compare
+    assertEquals(outputText, anotherStringOut.toString());
+  } // void testRoundTripISomeItemFromSomeItem
+} // class TestXmlizationOfInterfaces
+
+// package dummy.tests
+
+/*
+ * This code has been automatically generated by aas-core-codegen.
+ * Do NOT edit or append.
+ */
diff --git a/dev/test_data/main/java/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/java/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/java/expected/variance_of_containers/input/snippets/package.txt b/dev/test_data/main/java/expected/variance_of_containers/input/snippets/package.txt
new file mode 100644
index 000000000..2995a4d0e
--- /dev/null
+++ b/dev/test_data/main/java/expected/variance_of_containers/input/snippets/package.txt
@@ -0,0 +1 @@
+dummy
\ No newline at end of file
diff --git a/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/schema.json b/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/schema.json
new file mode 100644
index 000000000..9d938eee3
--- /dev/null
+++ b/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/schema.json
@@ -0,0 +1,133 @@
+{
+  "$schema": "https://json-schema.org/draft/2019-09/schema",
+  "title": "DummyForTest",
+  "type": "object",
+  "allOf": [
+    {
+      "$ref": "#/definitions/Container"
+    }
+  ],
+  "$id": "https://dummy.com",
+  "definitions": {
+    "Container": {
+      "type": "object",
+      "properties": {
+        "items": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/Item_choice"
+          }
+        },
+        "someItems": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/SomeItem_choice"
+          }
+        },
+        "specialItems": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/SpecialItem"
+          }
+        }
+      },
+      "required": [
+        "items",
+        "someItems"
+      ]
+    },
+    "Item": {
+      "type": "object",
+      "properties": {
+        "name": {
+          "type": "string"
+        },
+        "nickname": {
+          "type": "string"
+        },
+        "modelType": {
+          "$ref": "#/definitions/ModelType"
+        }
+      },
+      "required": [
+        "name",
+        "modelType"
+      ]
+    },
+    "Item_choice": {
+      "oneOf": [
+        {
+          "$ref": "#/definitions/SomeItem"
+        },
+        {
+          "$ref": "#/definitions/SpecialItem"
+        }
+      ]
+    },
+    "ModelType": {
+      "type": "string",
+      "enum": [
+        "SomeItem",
+        "SpecialItem"
+      ]
+    },
+    "SomeItem": {
+      "allOf": [
+        {
+          "$ref": "#/definitions/SomeItem_abstract"
+        },
+        {
+          "properties": {
+            "modelType": {
+              "const": "SomeItem"
+            }
+          }
+        }
+      ]
+    },
+    "SomeItem_abstract": {
+      "$ref": "#/definitions/Item"
+    },
+    "SomeItem_choice": {
+      "oneOf": [
+        {
+          "$ref": "#/definitions/SomeItem"
+        },
+        {
+          "$ref": "#/definitions/SpecialItem"
+        }
+      ]
+    },
+    "SpecialItem": {
+      "allOf": [
+        {
+          "$ref": "#/definitions/SomeItem_abstract"
+        },
+        {
+          "properties": {
+            "level": {
+              "type": "integer"
+            },
+            "modelType": {
+              "const": "SpecialItem"
+            }
+          },
+          "required": [
+            "level"
+          ]
+        }
+      ]
+    },
+    "Wrapper": {
+      "type": "object",
+      "properties": {
+        "container": {
+          "$ref": "#/definitions/Container"
+        }
+      },
+      "required": [
+        "container"
+      ]
+    }
+  }
+}
\ No newline at end of file
diff --git a/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/jsonschema/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/jsonschema/expected/variance_of_containers/input/snippets/schema_base.json b/dev/test_data/main/jsonschema/expected/variance_of_containers/input/snippets/schema_base.json
new file mode 100644
index 000000000..9c60bfeb7
--- /dev/null
+++ b/dev/test_data/main/jsonschema/expected/variance_of_containers/input/snippets/schema_base.json
@@ -0,0 +1,10 @@
+{
+  "$schema": "https://json-schema.org/draft/2019-09/schema",
+  "title": "DummyForTest",
+  "type": "object",
+  "allOf": [
+    {
+      "$ref": "#/definitions/Container"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common.py
new file mode 100644
index 000000000..023ae394b
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common.py
@@ -0,0 +1,138 @@
+"""Provide functionality used across the tests."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import base64
+import collections.abc
+import difflib
+import enum
+import io
+import os
+import pathlib
+import textwrap
+from typing import Union, Sequence
+
+
+import dummy.common as our_common
+import dummy.types as our_types
+
+
+_REPO_ROOT = pathlib.Path(os.path.realpath(__file__)).parent.parent.parent
+
+
+#: Path to the directory which contains input and golden files
+TEST_DATA_DIR = _REPO_ROOT / "test_data"
+
+
+#: If set, the golden files in the tests should be re-recorded instead
+#: of checked against.
+RECORD_MODE = os.environ.get("DUMMY_TESTS_RECORD_MODE", "").lower() in (
+    "1",
+    "on",
+    "true",
+)
+
+
+def record_or_check(path: pathlib.Path, got: str) -> None:
+    """
+    Re-record or check that :paramref:`got` content matches the content of
+    :paramref:`path`.
+
+    If :py:attr:`~RECORD_MODE` is set, the content of :paramref:`path` will be
+    simply overwritten with :paramref:`got` content, and no checks are performed.
+
+    :param path: to the golden file
+    :param got: obtained content
+    :raise: :py:class:`AssertionError` if the contents do not match
+    """
+    if RECORD_MODE:
+        path.parent.mkdir(exist_ok=True, parents=True)
+        path.write_text(got, encoding="utf-8")
+    else:
+        if not path.exists():
+            raise FileNotFoundError(
+                f"The golden file could not be found: {path}; did you record it?"
+            )
+
+        expected = path.read_text(encoding="utf-8")
+        if expected != got:
+            writer = io.StringIO()
+
+            diff = difflib.ndiff(
+                expected.splitlines(keepends=True), got.splitlines(keepends=True)
+            )
+
+            diff_text = "".join(diff)
+            writer.write(
+                f"""\
+The obtained content and the content of {path} do not match:
+{diff_text}"""
+            )
+
+            raise AssertionError(writer.getvalue())
+
+
+def trace(
+    that: Union[
+        bool,
+        int,
+        float,
+        str,
+        bytes,
+        enum.Enum,
+        our_types.Class,
+        Sequence[
+            Union[bool, int, float, str, bytes, enum.Enum, our_types.Class]
+        ],
+    ],
+) -> str:
+    """
+    Generate a segment in a trace of an iteration.
+
+    :param that: to be traced
+    :return: segment in the descent trace
+    """
+    if isinstance(that, our_types.Class):
+        return that.__class__.__name__
+    elif isinstance(that, (bool, int, float, str, enum.Enum)):
+        return str(that)
+    elif isinstance(that, bytes):
+        return base64.b64encode(that).decode("ascii")
+    elif isinstance(that, collections.abc.Sequence):
+        if len(that) == 0:
+            return "[]"
+        writer = io.StringIO()
+        writer.write("[\n")
+        for i, item in enumerate(that):
+            writer.write(textwrap.indent(trace(item), "  "))
+
+            if i < len(that) - 1:
+                writer.write(",\n")
+            else:
+                writer.write("\n")
+
+        writer.write("]")
+        return writer.getvalue()
+    else:
+        our_common.assert_never(that)
+
+
+def trace_log_as_text_file_content(log: Sequence[str]) -> str:
+    """
+    Convert the trace log to a text to be stored in a file.
+
+    :param log: to be converted to text
+    :return: content of the file, including the new-line at the end
+    """
+    writer = io.StringIO()
+    for entry in log:
+        writer.write(f"{entry}\n")
+    writer.write("\n")
+    return writer.getvalue()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_jsonization.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_jsonization.py
new file mode 100644
index 000000000..cd931e62f
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_jsonization.py
@@ -0,0 +1,197 @@
+"""Provide common functionality for JSON de/serialization in tests."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import collections.abc
+import json
+import pathlib
+import sys
+from typing import Callable, Iterator, Mapping, Type
+
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+
+import dummy.common as our_common
+import dummy.jsonization as our_jsonization
+import dummy.types as our_types
+
+
+class Difference:
+    """Represent a single difference between two JSON-ables."""
+
+    #: Human-readable description of the difference
+    message: Final[str]
+
+    #: Path in the expected JSON-able value which is different from
+    #: the obtained JSON-able value
+    path: Final[our_jsonization.Path]
+
+    def __init__(self, message: str) -> None:
+        """Initialize with the given message and empty path."""
+        self.message = message
+        self.path = our_jsonization.Path()
+
+    def __str__(self) -> str:
+        return f"#{self.path}: {self.message}"
+
+
+def check_equal(
+    expected: our_jsonization.Jsonable,
+    got: our_jsonization.Jsonable,
+) -> Iterator[Difference]:
+    """
+    Compare recursively two JSON-able values for equality.
+
+    :param expected: expected JSON-able value
+    :param got: obtained JSON-able value
+    :yield: differences
+    """
+    if isinstance(expected, (bool, int, float, str, bytes)):
+        if type(expected) != type(got):  # pylint: disable=unidiomatic-typecheck
+            yield Difference(f"Expected {type(expected)}, but got {type(got)}")
+
+        if expected != got:
+            yield Difference(f"Expected {expected!r}, but got {got!r}")
+    elif isinstance(expected, collections.abc.Sequence):
+        if not isinstance(got, collections.abc.Sequence):
+            yield Difference(f"Expected a sequence, but got {type(got)}")
+        else:
+            if len(expected) != len(got):
+                yield Difference(
+                    f"Expected a sequence of {len(expected)} item(s), "
+                    f"but got {len(got)} item(s)"
+                )
+
+            for i, (expected_item, got_item) in enumerate(zip(expected, got)):
+                for difference in check_equal(expected_item, got_item):
+                    difference.path._prepend(our_jsonization.IndexSegment(expected, i))
+                    yield difference
+
+    elif isinstance(expected, collections.abc.Mapping):
+        if not isinstance(got, collections.abc.Mapping):
+            yield Difference(f"Expected a mapping, but got {type(got)}")
+        else:
+            if not all(isinstance(key, str) for key in expected.keys()):
+                raise ValueError(
+                    f"Expected all keys in the expected JSON-able value to be strings, "
+                    f"but got: {list(expected.keys())}"
+                )
+
+            if not all(isinstance(key, str) for key in got.keys()):
+                yield Difference(
+                    f"Expected all keys in a mapping to be strings, "
+                    f"but got: {list(got.keys())}"
+                )
+
+            expected_key_set = set(expected.keys())
+            got_key_set = set(got.keys())
+
+            expected_got_diff = expected_key_set.difference(got_key_set)
+            if expected_got_diff:
+                yield Difference(f"Expected key(s) {sorted(expected_got_diff)} missing")
+
+            got_expected_diff = got_key_set.difference(expected_key_set)
+            if got_expected_diff:
+                yield Difference(f"Unexpected key(s) {sorted(got_expected_diff)}")
+
+            for key, expected_value in expected.items():
+                got_value = got[key]
+
+                for difference in check_equal(expected_value, got_value):
+                    difference.path._prepend(
+                        our_jsonization.PropertySegment(expected, key)
+                    )
+                    yield difference
+    else:
+        our_common.assert_never(expected)
+
+
+_MODEL_TYPE_TO_FROM_JSONABLE: Mapping[
+    str,
+    Callable[[our_jsonization.Jsonable], our_types.Class]
+] = {
+    'Container':
+        our_jsonization.container_from_jsonable,
+    'SomeItem':
+        our_jsonization.some_item_from_jsonable,
+    'SpecialItem':
+        our_jsonization.special_item_from_jsonable,
+    'Wrapper':
+        our_jsonization.wrapper_from_jsonable
+}
+
+
+_MODEL_TYPE_TO_CLASS: Mapping[
+    str,
+    Type[our_types.Class]
+] = {
+    'Container':
+        our_types.Container,
+    'SomeItem':
+        our_types.SomeItem,
+    'SpecialItem':
+        our_types.SpecialItem,
+    'Wrapper':
+        our_types.Wrapper
+}
+
+
+def must_load(
+    path: pathlib.Path,
+    model_type: str
+) -> our_types.Class:
+    """
+    Load an instance from ``path``.
+
+    The class of the instance must correspond to the ``model_type``.
+    """
+    try:
+        jsonable = json.loads(
+            path.read_text(encoding='utf-8')
+        )
+    except Exception as exception:
+        raise RuntimeError(f"Failed to read from {path}") from exception
+
+    from_jsonable = _MODEL_TYPE_TO_FROM_JSONABLE.get(model_type, None)
+    if from_jsonable is None:
+        raise AssertionError(
+            "The model type is not mapped to "
+            f"the from_jsonable function: {model_type!r}"
+        )
+
+    try:
+        instance = from_jsonable(jsonable)
+    except Exception as exception:
+        raise RuntimeError(
+            "Failed to parse the instance "
+            f"with model type {model_type} from {path}"
+        ) from exception
+
+    cls = _MODEL_TYPE_TO_CLASS.get(model_type, None)
+    if cls is None:
+        raise AssertionError(
+            "The model type is not mapped to the class: {model_type!r}"
+        )
+
+    if not isinstance(instance, cls):
+        raise RuntimeError(
+            f"Expected an instance with model type {model_type!r}, "
+            f"corresponding to class {cls}, "
+            f"but got an instance {instance}"
+        )
+
+    return instance
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_xmlization.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_xmlization.py
new file mode 100644
index 000000000..bf62d4b5e
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/common_xmlization.py
@@ -0,0 +1,186 @@
+"""Provide common functionality for XML de/serialization in tests."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import io
+import pathlib
+import sys
+from typing import Iterator, Optional
+import xml.etree.ElementTree as ET
+
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+
+import dummy.types as our_types
+import dummy.xmlization as our_xmlization
+
+
+class Difference:
+    """Represent a single difference between two XML documents."""
+
+    #: Human-readable description of the difference
+    message: Final[str]
+
+    #: Path to the expected XML element which is different from
+    #: the obtained XML element
+    path: Final[our_xmlization.Path]
+
+    def __init__(self, message: str) -> None:
+        """Initialize with the given message and empty path."""
+        self.message = message
+        self.path = our_xmlization.Path()
+
+    def __str__(self) -> str:
+        return f"#{self.path}: {self.message}"
+
+
+def remove_redundant_whitespace(element: ET.Element) -> None:
+    """
+    Remove the whitespace which will be ignored in the XML parsing.
+
+    :param element: to remove the whitespace from
+    """
+    if len(element) > 0:
+        if element.text is not None and len(element.text.strip()) == 0:
+            element.text = None
+
+        for child in element:
+            if child.tail is not None and len(child.tail.strip()) == 0:
+                child.tail = None
+
+            remove_redundant_whitespace(child)
+
+
+def check_equal(
+    expected: ET.Element,
+    got: ET.Element,
+) -> Iterator[Difference]:
+    """
+    Compare recursively two XML elements for equality.
+
+    Make sure you called :py:function:`.remove_redundant_whitespace`
+    so that your comparison does not trip over trivial whitespace.
+
+    :param expected: expected XML element
+    :param got: obtained XML element
+    :yield: differences
+    """
+    # NOTE (mristin):
+    # We need to ignore the white-space before the children as it is ignored
+    # by the XML parser.
+
+    stop_recursion = False
+    if expected.text is not None and got.text is None:
+        stop_recursion = True
+        yield Difference(f"Expected text {expected.text!r}, but got none")
+
+    if expected.text is None and got.text is not None:
+        stop_recursion = True
+        yield Difference(f"Expected no text, but got {got.text!r}")
+
+    if expected.tail is not None and got.tail is None:
+        stop_recursion = True
+        yield Difference(f"Expected tail {expected.tail!r}, but got none")
+
+    if expected.tail is None and got.tail is not None:
+        stop_recursion = True
+        yield Difference(f"Expected no tail, but got {got.tail!r}")
+
+    if expected.text is not None and got.text is not None and expected.text != got.text:
+        stop_recursion = True
+        yield Difference(f"Expected text {expected.text!r}, but got {got.text!r}")
+
+    if expected.tail is not None and got.tail is not None and expected.tail != got.tail:
+        stop_recursion = True
+        yield Difference(f"Expected tail {expected.tail!r}, but got {got.tail!r}")
+
+    if expected.tag != got.tag:
+        stop_recursion = True
+        yield Difference(f"Expected tail {expected.tag!r}, but got {got.tag!r}")
+
+    expected_children = [  # pylint: disable=unnecessary-comprehension
+        child for child in expected
+    ]
+
+    got_children = [child for child in got]  # pylint: disable=unnecessary-comprehension
+
+    if len(expected_children) != len(got_children):
+        stop_recursion = True
+        yield Difference(
+            f"Expected {len(expected_children)} child element(s), "
+            f"but got {len(got_children)} child element(s)"
+        )
+
+    children_tag_unique = len(set(child.tag for child in expected_children)) == len(
+        expected_children
+    )
+
+    if stop_recursion:
+        return
+
+    for i, (expected_child, got_child) in enumerate(
+        zip(expected_children, got_children)
+    ):
+        for difference in check_equal(expected_child, got_child):
+            if children_tag_unique:
+                difference.path._prepend(our_xmlization.ElementSegment(expected_child))
+            else:
+                difference.path._prepend(our_xmlization.IndexSegment(expected_child, i))
+
+            yield difference
+
+
+def assert_elements_equal(
+    expected: ET.Element, got: ET.Element, message_if_not_equal: Optional[str] = None
+) -> None:
+    """
+    Assert that the two elements are equal.
+
+    Make sure you called :py:function:`.remove_redundant_whitespace`
+    so that your comparison does not trip over trivial whitespace.
+
+    :param expected: what you expected
+    :param got: what you got
+    :param message_if_not_equal: description or identifier to help debugging
+    :raise: :py:class:`AssertionError` if the two elements are not equal
+    """
+    findings_text = "\n".join(
+        str(difference) for difference in check_equal(expected=expected, got=got)
+    )
+
+    if len(findings_text) != 0:
+        writer = io.StringIO()
+        writer.write(
+            f"Expected two elements to be equal, but they are not. "
+            f"Differences related to the expected element:\n"
+            f"{findings_text}"
+        )
+
+        if message_if_not_equal is not None:
+            writer.write("\n\n")
+            writer.write(message_if_not_equal)
+
+        raise AssertionError(writer.getvalue())
+
+
+def must_load(
+    path: pathlib.Path,
+) -> our_types.Class:
+    """Load an instance from ``path``."""
+    try:
+        instance = our_xmlization.from_file(path)
+    except Exception as exception:
+        raise RuntimeError(f"Failed to read from {path}") from exception
+
+    return instance
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_and_pass_through_visitor.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_and_pass_through_visitor.py
new file mode 100644
index 000000000..cc2af20ea
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_and_pass_through_visitor.py
@@ -0,0 +1,112 @@
+"""
+Test jointly :py:method:`dummy.types.Class.descend` and
+:py:method:`dummy.types.PassThroughVisitor`.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+from typing import (
+    List,
+    Sequence
+)
+import unittest
+
+
+import dummy.types as our_types
+
+
+import tests.common
+import tests.common_xmlization
+
+
+class _TracingVisitor(our_types.PassThroughVisitor):
+    """Visit the instances and trace them."""
+
+    def __init__(self) -> None:
+        """Initialize with an empty log."""
+        self._log = []  # type: List[str]
+
+    @property
+    def log(self) -> Sequence[str]:
+        """Get the tracing log."""
+        return self._log
+
+    def visit(self, that: our_types.Class) -> None:
+        self._log.append(tests.common.trace(that))
+        super().visit(that)
+
+
+def assert_tracing_logs_from_descend_and_visitor_are_the_same(
+    that: our_types.Class, test_case: unittest.TestCase
+) -> None:
+    """
+    Check that the tracing logs are the same when :paramref:`that` instance
+    is visited and when :paramref:`that` is ran through
+    :py:method:`our_types.Class.descend`.
+
+    :param that: instance to be iterated over
+    :param test_case: in which this assertion runs
+    :raise: :py:class:`AssertionError` if the logs differ
+    """
+    log_from_descend = [tests.common.trace(something) for something in that.descend()]
+
+    visitor = _TracingVisitor()
+    visitor.visit(that)
+    log_from_visitor = visitor.log
+
+    test_case.assertGreater(len(log_from_visitor), 0)
+    test_case.assertEqual(tests.common.trace(that), log_from_visitor[0])
+
+    # noinspection PyTypeChecker
+    test_case.assertListEqual(log_from_descend, log_from_visitor[1:])  # type: ignore
+
+
+class TestWithExpectedMaximal(unittest.TestCase):
+    def test_descend_against_recorded_trace_log(self) -> None:
+        xml_expected_dir = tests.common.TEST_DATA_DIR / "Xml" / "Expected"
+
+        for path in sorted(xml_expected_dir.glob("**/maximal.xml")):
+            instance = tests.common_xmlization.must_load(path)
+
+            rel_path = path.relative_to(xml_expected_dir)
+
+            expected_path = (
+                tests.common.TEST_DATA_DIR
+                / "descend_and_pass_through_visitor"
+                / rel_path.parent
+                / f"{rel_path.name}.trace"
+            )
+
+            log = [
+                tests.common.trace(something)
+                for something in instance.descend()
+            ]
+
+            got_text = tests.common.trace_log_as_text_file_content(log)
+
+            tests.common.record_or_check(expected_path, got_text)
+
+    def test_descend_against_visitor(self) -> None:
+        xml_expected_dir = tests.common.TEST_DATA_DIR / "Xml" / "Expected"
+
+        for path in sorted(xml_expected_dir.glob("**/maximal.xml")):
+            instance = tests.common_xmlization.must_load(path)
+
+            assert_tracing_logs_from_descend_and_visitor_are_the_same(
+                instance,
+                self
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_once.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_once.py
new file mode 100644
index 000000000..4d85ef319
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_descend_once.py
@@ -0,0 +1,49 @@
+"""Test :py:method:`dummy.types.Class.descend_once`."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import unittest
+
+
+import tests.common
+import tests.common_xmlization
+
+
+class TestWithExpectedMaximal(unittest.TestCase):
+    def test_descend_once_against_recorded_trace_log(self) -> None:
+        xml_expected_dir = tests.common.TEST_DATA_DIR / "Xml" / "Expected"
+
+        for path in sorted(xml_expected_dir.glob("**/maximal.xml")):
+            instance = tests.common_xmlization.must_load(path)
+
+            rel_path = path.relative_to(xml_expected_dir)
+
+            expected_path = (
+                tests.common.TEST_DATA_DIR
+                / "descend_once"
+                / rel_path.parent
+                / f"{rel_path.name}.trace"
+            )
+
+            log = [
+                tests.common.trace(something)
+                for something in instance.descend_once()
+            ]
+
+            got_text = tests.common.trace_log_as_text_file_content(log)
+
+            tests.common.record_or_check(expected_path, got_text)
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_over_X_or_empty.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_over_X_or_empty.py
new file mode 100644
index 000000000..b3b90c3b3
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_over_X_or_empty.py
@@ -0,0 +1,64 @@
+"""Test ``over_X_or_empty`` methods."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import pathlib
+import unittest
+
+
+import dummy.types as our_types
+
+
+import tests.common
+import tests.common_xmlization
+
+
+class TestContainer(unittest.TestCase):
+    def test_over_special_items_or_empty_against_recorded(self) -> None:
+        for minimal_or_maximal in ["minimal", "maximal"]:
+            instance = tests.common_xmlization.must_load(
+                pathlib.Path(
+                    tests.common.TEST_DATA_DIR
+                    / "Xml"
+                    / "Expected"
+                    / 'container'
+                    / f"{minimal_or_maximal}.xml"
+                )
+            )
+
+            assert isinstance(
+                instance,
+                our_types.Container
+            )
+
+            log = [
+                tests.common.trace(
+                    list(instance.over_special_items_or_empty())
+                )
+            ]
+
+            got_text = tests.common.trace_log_as_text_file_content(log)
+
+            expected_path = pathlib.Path(
+                tests.common.TEST_DATA_DIR
+                / "test_over_X_or_empty"
+                / 'container'
+                / f"on_{minimal_or_maximal}.xml"
+                / 'over_special_items_or_empty.trace'
+            )
+
+            tests.common.record_or_check(expected_path, got_text)
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_x_or_default.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_x_or_default.py
new file mode 100644
index 000000000..3538a9f6f
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_for_x_or_default.py
@@ -0,0 +1,27 @@
+"""Test ``X_or_default`` methods."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import pathlib
+import unittest
+
+
+import dummy.types as our_types
+
+
+import tests.common
+import tests.common_xmlization
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_classes_with_descendants.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_classes_with_descendants.py
new file mode 100644
index 000000000..8798d4cec
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_classes_with_descendants.py
@@ -0,0 +1,86 @@
+"""Test JSON de/serialization of classes with descendants."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import json
+import unittest
+
+
+import dummy.jsonization as our_jsonization
+
+
+import tests.common
+import tests.common_jsonization
+
+
+class TestRoundTrips(unittest.TestCase):
+    def test_item(self) -> None:
+        for descendant_model_type in [
+            'SomeItem',
+            'SpecialItem'
+        ]:
+            for path in sorted(
+                (
+                    tests.common.TEST_DATA_DIR
+                    / "Json"
+                    / "Expected"
+                    / descendant_model_type
+                ).glob("**/*.json")
+            ):
+                with path.open("rt") as fid:
+                    original_jsonable = json.load(fid)
+
+                instance = our_jsonization.item_from_jsonable(
+                    original_jsonable
+                )
+
+                another_jsonable = our_jsonization.to_jsonable(instance)
+
+                mismatch = tests.common_jsonization.check_equal(
+                    original_jsonable,
+                    another_jsonable
+                )
+
+                self.assertListEqual([], list(map(str, mismatch)))
+
+    def test_some_item(self) -> None:
+        for descendant_model_type in [
+            'SpecialItem'
+        ]:
+            for path in sorted(
+                (
+                    tests.common.TEST_DATA_DIR
+                    / "Json"
+                    / "Expected"
+                    / descendant_model_type
+                ).glob("**/*.json")
+            ):
+                with path.open("rt") as fid:
+                    original_jsonable = json.load(fid)
+
+                instance = our_jsonization.some_item_from_jsonable(
+                    original_jsonable
+                )
+
+                another_jsonable = our_jsonization.to_jsonable(instance)
+
+                mismatch = tests.common_jsonization.check_equal(
+                    original_jsonable,
+                    another_jsonable
+                )
+
+                self.assertListEqual([], list(map(str, mismatch)))
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_concrete_classes.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_concrete_classes.py
new file mode 100644
index 000000000..3f6b3a645
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_concrete_classes.py
@@ -0,0 +1,166 @@
+"""Test JSON de/serialization of concrete classes."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import json
+import math
+from typing import Any
+import unittest
+
+
+import dummy.jsonization as our_jsonization
+
+
+import tests.common
+import tests.common_jsonization
+
+
+class TestRoundTrips(unittest.TestCase):
+    def test_some_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'SomeItem'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                original_jsonable = json.load(fid)
+
+            instance = our_jsonization.some_item_from_jsonable(
+                original_jsonable
+            )
+
+            another_jsonable = our_jsonization.to_jsonable(instance)
+
+            mismatches = tests.common_jsonization.check_equal(
+                original_jsonable,
+                another_jsonable
+            )
+            self.assertListEqual([], list(map(str, mismatches)))
+
+    def test_special_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'SpecialItem'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                original_jsonable = json.load(fid)
+
+            instance = our_jsonization.special_item_from_jsonable(
+                original_jsonable
+            )
+
+            another_jsonable = our_jsonization.to_jsonable(instance)
+
+            mismatches = tests.common_jsonization.check_equal(
+                original_jsonable,
+                another_jsonable
+            )
+            self.assertListEqual([], list(map(str, mismatches)))
+
+    def test_container(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'Container'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                original_jsonable = json.load(fid)
+
+            instance = our_jsonization.container_from_jsonable(
+                original_jsonable
+            )
+
+            another_jsonable = our_jsonization.to_jsonable(instance)
+
+            mismatches = tests.common_jsonization.check_equal(
+                original_jsonable,
+                another_jsonable
+            )
+            self.assertListEqual([], list(map(str, mismatches)))
+
+    def test_wrapper(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'Wrapper'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                original_jsonable = json.load(fid)
+
+            instance = our_jsonization.wrapper_from_jsonable(
+                original_jsonable
+            )
+
+            another_jsonable = our_jsonization.to_jsonable(instance)
+
+            mismatches = tests.common_jsonization.check_equal(
+                original_jsonable,
+                another_jsonable
+            )
+            self.assertListEqual([], list(map(str, mismatches)))
+
+
+def _load_the_first_expected(model_type: str) -> Any:
+    """Load the first recorded example of the ``model_type``."""
+    paths = sorted(
+        (
+            tests.common.TEST_DATA_DIR
+            / "Json"
+            / "Expected"
+            / model_type
+        ).glob("**/*.json")
+    )
+
+    assert len(paths) > 0, (
+        f"Expected at least one recorded example of {model_type}, but got none"
+    )
+
+    with paths[0].open("rt") as fid:
+        return json.load(fid)
+
+
+class TestSerializationFailures(unittest.TestCase):
+    def test_special_item_level_out_of_range(self) -> None:
+        for value in [9007199254740992, -9007199254740992]:
+            instance = our_jsonization.special_item_from_jsonable(
+                _load_the_first_expected('SpecialItem')
+            )
+
+            instance.level = value
+
+            with self.assertRaises(
+                our_jsonization.SerializationException
+            ) as context_manager:
+                our_jsonization.to_jsonable(instance)
+
+            self.assertEqual(
+                '.level',
+                context_manager.exception.path
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_enums.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_enums.py
new file mode 100644
index 000000000..fac1a9596
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_jsonization_of_enums.py
@@ -0,0 +1,26 @@
+"""Test JSON de/serialization of enumerations."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import unittest
+
+
+import dummy.jsonization as our_jsonization
+
+
+class TestRoundTrips(unittest.TestCase):
+    pass
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_len_slicing_and_find.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_len_slicing_and_find.py
new file mode 100644
index 000000000..31d330fc3
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_len_slicing_and_find.py
@@ -0,0 +1,310 @@
+"""
+Test ``len``, the slicing of strings and ``find`` as used in the transpiled code.
+
+The transpiled code follows the Python implementation, since Python is
+the language of the meta-model specifications. Hence, the lengths and
+the positions count the characters (code points). The other SDKs test against
+the very same cases.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import unittest
+
+
+class Test_len_slicing_and_find(unittest.TestCase):
+    def test_len_empty_text(self) -> None:
+        self.assertEqual(
+            0,
+            len('')
+        )
+
+    def test_len_ascii_text(self) -> None:
+        self.assertEqual(
+            3,
+            len('abc')
+        )
+
+    def test_len_character_of_two_utf_8_bytes(self) -> None:
+        self.assertEqual(
+            2,
+            len('é-')
+        )
+
+    def test_len_character_beyond_the_basic_multilingual_plane(self) -> None:
+        self.assertEqual(
+            2,
+            len('😀-')
+        )
+
+    def test_len_mixed_characters(self) -> None:
+        self.assertEqual(
+            5,
+            len('aé😀b😀')
+        )
+
+    def test_slice_start_and_end(self) -> None:
+        self.assertEqual(
+            'bc',
+            'abcde'[1:3]
+        )
+
+    def test_slice_no_start(self) -> None:
+        self.assertEqual(
+            'ab',
+            'abcde'[:2]
+        )
+
+    def test_slice_no_end(self) -> None:
+        self.assertEqual(
+            'de',
+            'abcde'[3:]
+        )
+
+    def test_slice_neither_start_nor_end(self) -> None:
+        self.assertEqual(
+            'abcde',
+            'abcde'[:]
+        )
+
+    def test_slice_negative_start_counts_from_the_end(self) -> None:
+        self.assertEqual(
+            'de',
+            'abcde'[-2:]
+        )
+
+    def test_slice_negative_end_counts_from_the_end(self) -> None:
+        self.assertEqual(
+            'abc',
+            'abcde'[:-2]
+        )
+
+    def test_slice_negative_start_and_end(self) -> None:
+        self.assertEqual(
+            'bcd',
+            'abcde'[-4:-1]
+        )
+
+    def test_slice_negative_start_before_the_beginning_is_clamped(self) -> None:
+        self.assertEqual(
+            'ab',
+            'abcde'[-10:2]
+        )
+
+    def test_slice_end_beyond_the_end_is_clamped(self) -> None:
+        self.assertEqual(
+            'cde',
+            'abcde'[2:10]
+        )
+
+    def test_slice_start_beyond_the_end_gives_empty(self) -> None:
+        self.assertEqual(
+            '',
+            'abcde'[10:]
+        )
+
+    def test_slice_start_after_end_gives_empty(self) -> None:
+        self.assertEqual(
+            '',
+            'abcde'[3:1]
+        )
+
+    def test_slice_negative_start_after_negative_end_gives_empty(self) -> None:
+        self.assertEqual(
+            '',
+            'abcde'[-1:-3]
+        )
+
+    def test_slice_start_equal_to_end_gives_empty(self) -> None:
+        self.assertEqual(
+            '',
+            'abcde'[5:5]
+        )
+
+    def test_slice_empty_text(self) -> None:
+        self.assertEqual(
+            '',
+            ''[0:0]
+        )
+
+    def test_slice_negative_start_on_empty_text(self) -> None:
+        self.assertEqual(
+            '',
+            ''[-1:]
+        )
+
+    def test_slice_end_beyond_the_end_of_empty_text(self) -> None:
+        self.assertEqual(
+            '',
+            ''[:5]
+        )
+
+    def test_slice_after_a_character_of_two_utf_8_bytes(self) -> None:
+        self.assertEqual(
+            '-x',
+            'é-x'[1:]
+        )
+
+    def test_slice_character_of_two_utf_8_bytes(self) -> None:
+        self.assertEqual(
+            'é',
+            'aéb'[1:2]
+        )
+
+    def test_slice_character_beyond_the_basic_multilingual_plane(self) -> None:
+        self.assertEqual(
+            '😀',
+            'a😀b'[1:2]
+        )
+
+    def test_slice_after_a_character_beyond_the_basic_multilingual_plane(self) -> None:
+        self.assertEqual(
+            '-x',
+            '😀-x'[1:]
+        )
+
+    def test_slice_negative_start_on_characters_beyond_ascii(self) -> None:
+        self.assertEqual(
+            '😀b',
+            'aé😀b😀'[-3:-1]
+        )
+
+    def test_find_found(self) -> None:
+        self.assertEqual(
+            1,
+            'abcabc'.find('b')
+        )
+
+    def test_find_not_found(self) -> None:
+        self.assertEqual(
+            -1,
+            'abcabc'.find('x')
+        )
+
+    def test_find_empty_sub(self) -> None:
+        self.assertEqual(
+            0,
+            'abcabc'.find('')
+        )
+
+    def test_find_sub_longer_than_text(self) -> None:
+        self.assertEqual(
+            -1,
+            'ab'.find('abc')
+        )
+
+    def test_find_found_after_start(self) -> None:
+        self.assertEqual(
+            4,
+            'abcabc'.find('b', 2)
+        )
+
+    def test_find_found_only_before_start(self) -> None:
+        self.assertEqual(
+            -1,
+            'abcabc'.find('b', 5)
+        )
+
+    def test_find_negative_start_counts_from_the_end(self) -> None:
+        self.assertEqual(
+            5,
+            'abcabc'.find('c', -1)
+        )
+
+    def test_find_negative_start_finds_the_later_occurrence(self) -> None:
+        self.assertEqual(
+            3,
+            'abcabc'.find('a', -3)
+        )
+
+    def test_find_negative_start_before_the_beginning_is_clamped(self) -> None:
+        self.assertEqual(
+            0,
+            'abcabc'.find('a', -10)
+        )
+
+    def test_find_empty_sub_at_the_end(self) -> None:
+        self.assertEqual(
+            6,
+            'abcabc'.find('', 6)
+        )
+
+    def test_find_empty_sub_beyond_the_end_gives_1(self) -> None:
+        self.assertEqual(
+            -1,
+            'abcabc'.find('', 7)
+        )
+
+    def test_find_start_beyond_the_end_gives_1(self) -> None:
+        self.assertEqual(
+            -1,
+            'abcabc'.find('c', 10)
+        )
+
+    def test_find_empty_sub_in_empty_text(self) -> None:
+        self.assertEqual(
+            0,
+            ''.find('')
+        )
+
+    def test_find_empty_sub_beyond_the_end_of_empty_text_gives_1(self) -> None:
+        self.assertEqual(
+            -1,
+            ''.find('', 1)
+        )
+
+    def test_find_not_found_in_empty_text(self) -> None:
+        self.assertEqual(
+            -1,
+            ''.find('x')
+        )
+
+    def test_find_after_a_character_of_two_utf_8_bytes(self) -> None:
+        self.assertEqual(
+            1,
+            'é-'.find('-')
+        )
+
+    def test_find_after_a_character_beyond_the_basic_multilingual_plane(self) -> None:
+        self.assertEqual(
+            1,
+            '😀-'.find('-')
+        )
+
+    def test_find_character_beyond_the_basic_multilingual_plane(self) -> None:
+        self.assertEqual(
+            1,
+            'a😀b'.find('😀')
+        )
+
+    def test_find_start_after_a_character_beyond_ascii(self) -> None:
+        self.assertEqual(
+            3,
+            '😀a😀a'.find('a', 2)
+        )
+
+    def test_find_negative_start_on_characters_beyond_ascii(self) -> None:
+        self.assertEqual(
+            2,
+            '😀a😀a'.find('😀', -2)
+        )
+
+    def test_find_start_beyond_the_end_of_characters_beyond_ascii(self) -> None:
+        self.assertEqual(
+            -1,
+            'é😀'.find('', 3)
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_verification.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_verification.py
new file mode 100644
index 000000000..dff8a12db
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_verification.py
@@ -0,0 +1,295 @@
+"""Test the verification of instances."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import json
+import unittest
+
+
+import dummy.jsonization as our_jsonization
+import dummy.verification as our_verification
+
+
+import tests.common
+
+
+class TestVerificationOfValidInstances(unittest.TestCase):
+    def test_some_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'SomeItem'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                jsonable = json.load(fid)
+
+            instance = our_jsonization.some_item_from_jsonable(jsonable)
+
+            errors = list(our_verification.verify(instance))
+
+            if len(errors) > 0:
+                self.fail(
+                    f"Expected no errors when verifying the instance de-serialized "
+                    f"from {path}, but got {len(errors)} error(s):\n"
+                    + "\n".join(
+                        f"{error.path}: {error.cause}" for error in errors
+                    )
+                )
+
+    def test_special_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'SpecialItem'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                jsonable = json.load(fid)
+
+            instance = our_jsonization.special_item_from_jsonable(jsonable)
+
+            errors = list(our_verification.verify(instance))
+
+            if len(errors) > 0:
+                self.fail(
+                    f"Expected no errors when verifying the instance de-serialized "
+                    f"from {path}, but got {len(errors)} error(s):\n"
+                    + "\n".join(
+                        f"{error.path}: {error.cause}" for error in errors
+                    )
+                )
+
+    def test_container(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'Container'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                jsonable = json.load(fid)
+
+            instance = our_jsonization.container_from_jsonable(jsonable)
+
+            errors = list(our_verification.verify(instance))
+
+            if len(errors) > 0:
+                self.fail(
+                    f"Expected no errors when verifying the instance de-serialized "
+                    f"from {path}, but got {len(errors)} error(s):\n"
+                    + "\n".join(
+                        f"{error.path}: {error.cause}" for error in errors
+                    )
+                )
+
+    def test_wrapper(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Expected"
+                / 'Wrapper'
+            ).glob("**/*.json")
+        ):
+            with path.open("rt") as fid:
+                jsonable = json.load(fid)
+
+            instance = our_jsonization.wrapper_from_jsonable(jsonable)
+
+            errors = list(our_verification.verify(instance))
+
+            if len(errors) > 0:
+                self.fail(
+                    f"Expected no errors when verifying the instance de-serialized "
+                    f"from {path}, but got {len(errors)} error(s):\n"
+                    + "\n".join(
+                        f"{error.path}: {error.cause}" for error in errors
+                    )
+                )
+
+
+class TestVerificationOfInvalidInstances(unittest.TestCase):
+    def test_some_item(self) -> None:
+        for cause_dir in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Unexpected"
+                / "Invalid"
+            ).iterdir()
+        ):
+            for path in sorted(
+                (cause_dir / 'SomeItem').glob("**/*.json")
+            ):
+                rel_path = path.relative_to(tests.common.TEST_DATA_DIR)
+
+                expected_path = (
+                    tests.common.TEST_DATA_DIR
+                    / "VerificationError"
+                    / rel_path.parent
+                    / f"{rel_path.name}.errors"
+                )
+
+                with path.open("rt") as fid:
+                    jsonable = json.load(fid)
+
+                instance = our_jsonization.some_item_from_jsonable(jsonable)
+
+                errors = list(our_verification.verify(instance))
+
+                if len(errors) == 0:
+                    self.fail(
+                        f"Expected at least one verification error "
+                        f"when verifying the instance de-serialized "
+                        f"from {path}, but got none"
+                    )
+
+                got = "\n".join(
+                    f"{error.path}: {error.cause}" for error in errors
+                ) + "\n"
+
+                tests.common.record_or_check(expected_path, got)
+
+    def test_special_item(self) -> None:
+        for cause_dir in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Unexpected"
+                / "Invalid"
+            ).iterdir()
+        ):
+            for path in sorted(
+                (cause_dir / 'SpecialItem').glob("**/*.json")
+            ):
+                rel_path = path.relative_to(tests.common.TEST_DATA_DIR)
+
+                expected_path = (
+                    tests.common.TEST_DATA_DIR
+                    / "VerificationError"
+                    / rel_path.parent
+                    / f"{rel_path.name}.errors"
+                )
+
+                with path.open("rt") as fid:
+                    jsonable = json.load(fid)
+
+                instance = our_jsonization.special_item_from_jsonable(jsonable)
+
+                errors = list(our_verification.verify(instance))
+
+                if len(errors) == 0:
+                    self.fail(
+                        f"Expected at least one verification error "
+                        f"when verifying the instance de-serialized "
+                        f"from {path}, but got none"
+                    )
+
+                got = "\n".join(
+                    f"{error.path}: {error.cause}" for error in errors
+                ) + "\n"
+
+                tests.common.record_or_check(expected_path, got)
+
+    def test_container(self) -> None:
+        for cause_dir in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Unexpected"
+                / "Invalid"
+            ).iterdir()
+        ):
+            for path in sorted(
+                (cause_dir / 'Container').glob("**/*.json")
+            ):
+                rel_path = path.relative_to(tests.common.TEST_DATA_DIR)
+
+                expected_path = (
+                    tests.common.TEST_DATA_DIR
+                    / "VerificationError"
+                    / rel_path.parent
+                    / f"{rel_path.name}.errors"
+                )
+
+                with path.open("rt") as fid:
+                    jsonable = json.load(fid)
+
+                instance = our_jsonization.container_from_jsonable(jsonable)
+
+                errors = list(our_verification.verify(instance))
+
+                if len(errors) == 0:
+                    self.fail(
+                        f"Expected at least one verification error "
+                        f"when verifying the instance de-serialized "
+                        f"from {path}, but got none"
+                    )
+
+                got = "\n".join(
+                    f"{error.path}: {error.cause}" for error in errors
+                ) + "\n"
+
+                tests.common.record_or_check(expected_path, got)
+
+    def test_wrapper(self) -> None:
+        for cause_dir in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Json"
+                / "Unexpected"
+                / "Invalid"
+            ).iterdir()
+        ):
+            for path in sorted(
+                (cause_dir / 'Wrapper').glob("**/*.json")
+            ):
+                rel_path = path.relative_to(tests.common.TEST_DATA_DIR)
+
+                expected_path = (
+                    tests.common.TEST_DATA_DIR
+                    / "VerificationError"
+                    / rel_path.parent
+                    / f"{rel_path.name}.errors"
+                )
+
+                with path.open("rt") as fid:
+                    jsonable = json.load(fid)
+
+                instance = our_jsonization.wrapper_from_jsonable(jsonable)
+
+                errors = list(our_verification.verify(instance))
+
+                if len(errors) == 0:
+                    self.fail(
+                        f"Expected at least one verification error "
+                        f"when verifying the instance de-serialized "
+                        f"from {path}, but got none"
+                    )
+
+                got = "\n".join(
+                    f"{error.path}: {error.cause}" for error in errors
+                ) + "\n"
+
+                tests.common.record_or_check(expected_path, got)
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_classes_with_descendants.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_classes_with_descendants.py
new file mode 100644
index 000000000..b35eaa4c4
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_classes_with_descendants.py
@@ -0,0 +1,133 @@
+"""Test XML de/serialization of classes with descendants."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import io
+import pathlib
+import tempfile
+import unittest
+import xml.etree.ElementTree as ET
+
+
+import dummy.xmlization as our_xmlization
+
+
+import tests.common
+import tests.common_xmlization
+
+
+class TestRoundTrips(unittest.TestCase):
+    def test_item(self) -> None:
+        for xml_class_name_of_descendant in [
+            'someItem',
+            'specialItem'
+        ]:
+            for path in sorted(
+                (
+                    tests.common.TEST_DATA_DIR
+                    / "Xml"
+                    / "Expected"
+                    / xml_class_name_of_descendant
+                ).glob("**/*.xml")
+            ):
+                text = path.read_text(encoding="utf-8")
+                et_concrete = ET.fromstring(text)
+                tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+                # region From iterparse
+                iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+                got_from_iterparse = our_xmlization.item_from_iterparse(iterator)
+
+                et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+                # endregion
+
+                # region From stream
+                got_from_stream = our_xmlization.item_from_stream(io.StringIO(text))
+                et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+                # endregion
+
+                # region From file
+                with tempfile.TemporaryDirectory() as tmp_dir:
+                    path = pathlib.Path(tmp_dir) / "something.xml"
+                    path.write_text(text, encoding="utf-8")
+
+                    got_from_file = our_xmlization.item_from_file(path)
+                et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+                # endregion
+
+                # region From string
+                got_from_str = our_xmlization.item_from_str(text)
+                et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+                # endregion
+
+    def test_some_item(self) -> None:
+        for xml_class_name_of_descendant in [
+            'specialItem'
+        ]:
+            for path in sorted(
+                (
+                    tests.common.TEST_DATA_DIR
+                    / "Xml"
+                    / "Expected"
+                    / xml_class_name_of_descendant
+                ).glob("**/*.xml")
+            ):
+                text = path.read_text(encoding="utf-8")
+                et_concrete = ET.fromstring(text)
+                tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+                # region From iterparse
+                iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+                got_from_iterparse = our_xmlization.some_item_from_iterparse(iterator)
+
+                et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+                # endregion
+
+                # region From stream
+                got_from_stream = our_xmlization.some_item_from_stream(io.StringIO(text))
+                et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+                # endregion
+
+                # region From file
+                with tempfile.TemporaryDirectory() as tmp_dir:
+                    path = pathlib.Path(tmp_dir) / "something.xml"
+                    path.write_text(text, encoding="utf-8")
+
+                    got_from_file = our_xmlization.some_item_from_file(path)
+                et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+                # endregion
+
+                # region From string
+                got_from_str = our_xmlization.some_item_from_str(text)
+                et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+                tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+                tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+                # endregion
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_concrete_classes.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_concrete_classes.py
new file mode 100644
index 000000000..aead49acb
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dev/tests/test_xmlization_of_concrete_classes.py
@@ -0,0 +1,314 @@
+"""Test XML de/serialization of concrete classes."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+# pylint: disable=missing-docstring
+
+
+import io
+import pathlib
+import tempfile
+import math
+import unittest
+import xml.etree.ElementTree as ET
+
+
+import dummy.types as our_types
+import dummy.xmlization as our_xmlization
+
+
+import tests.common
+import tests.common_xmlization
+
+
+class TestRoundTrips(unittest.TestCase):
+    def test_some_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Xml"
+                / "Expected"
+                / 'someItem'
+            ).glob("**/*.xml")
+        ):
+            text = path.read_text(encoding="utf-8")
+            et_concrete = ET.fromstring(text)
+            tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+            # region From iterparse
+            iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+            got_from_iterparse = (
+                our_xmlization.some_item_from_iterparse(iterator)
+            )
+
+            et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+            # endregion
+
+            # region From stream
+            got_from_stream = (
+                our_xmlization
+                .some_item_from_stream(
+                    io.StringIO(text)
+                )
+            )
+            et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+            # endregion
+
+            # region From file
+            with tempfile.TemporaryDirectory() as tmp_dir:
+                path = pathlib.Path(tmp_dir) / "something.xml"
+                path.write_text(text, encoding="utf-8")
+
+                got_from_file = (
+                    our_xmlization
+                    .some_item_from_file(path)
+                )
+            et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+            # endregion
+
+            # region From string
+            got_from_str = (
+                our_xmlization
+                .some_item_from_str(text)
+            )
+            et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+            # endregion
+
+    def test_special_item(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Xml"
+                / "Expected"
+                / 'specialItem'
+            ).glob("**/*.xml")
+        ):
+            text = path.read_text(encoding="utf-8")
+            et_concrete = ET.fromstring(text)
+            tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+            # region From iterparse
+            iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+            got_from_iterparse = (
+                our_xmlization.special_item_from_iterparse(iterator)
+            )
+
+            et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+            # endregion
+
+            # region From stream
+            got_from_stream = (
+                our_xmlization
+                .special_item_from_stream(
+                    io.StringIO(text)
+                )
+            )
+            et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+            # endregion
+
+            # region From file
+            with tempfile.TemporaryDirectory() as tmp_dir:
+                path = pathlib.Path(tmp_dir) / "something.xml"
+                path.write_text(text, encoding="utf-8")
+
+                got_from_file = (
+                    our_xmlization
+                    .special_item_from_file(path)
+                )
+            et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+            # endregion
+
+            # region From string
+            got_from_str = (
+                our_xmlization
+                .special_item_from_str(text)
+            )
+            et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+            # endregion
+
+    def test_container(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Xml"
+                / "Expected"
+                / 'container'
+            ).glob("**/*.xml")
+        ):
+            text = path.read_text(encoding="utf-8")
+            et_concrete = ET.fromstring(text)
+            tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+            # region From iterparse
+            iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+            got_from_iterparse = (
+                our_xmlization.container_from_iterparse(iterator)
+            )
+
+            et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+            # endregion
+
+            # region From stream
+            got_from_stream = (
+                our_xmlization
+                .container_from_stream(
+                    io.StringIO(text)
+                )
+            )
+            et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+            # endregion
+
+            # region From file
+            with tempfile.TemporaryDirectory() as tmp_dir:
+                path = pathlib.Path(tmp_dir) / "something.xml"
+                path.write_text(text, encoding="utf-8")
+
+                got_from_file = (
+                    our_xmlization
+                    .container_from_file(path)
+                )
+            et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+            # endregion
+
+            # region From string
+            got_from_str = (
+                our_xmlization
+                .container_from_str(text)
+            )
+            et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+            # endregion
+
+    def test_wrapper(self) -> None:
+        for path in sorted(
+            (
+                tests.common.TEST_DATA_DIR
+                / "Xml"
+                / "Expected"
+                / 'wrapper'
+            ).glob("**/*.xml")
+        ):
+            text = path.read_text(encoding="utf-8")
+            et_concrete = ET.fromstring(text)
+            tests.common_xmlization.remove_redundant_whitespace(et_concrete)
+
+            # region From iterparse
+            iterator = ET.iterparse(source=io.StringIO(text), events=["start", "end"])
+            got_from_iterparse = (
+                our_xmlization.wrapper_from_iterparse(iterator)
+            )
+
+            et_from_iterparse = ET.fromstring(our_xmlization.to_str(got_from_iterparse))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_iterparse)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_iterparse)
+            # endregion
+
+            # region From stream
+            got_from_stream = (
+                our_xmlization
+                .wrapper_from_stream(
+                    io.StringIO(text)
+                )
+            )
+            et_from_stream = ET.fromstring(our_xmlization.to_str(got_from_stream))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_stream)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_stream)
+            # endregion
+
+            # region From file
+            with tempfile.TemporaryDirectory() as tmp_dir:
+                path = pathlib.Path(tmp_dir) / "something.xml"
+                path.write_text(text, encoding="utf-8")
+
+                got_from_file = (
+                    our_xmlization
+                    .wrapper_from_file(path)
+                )
+            et_from_file = ET.fromstring(our_xmlization.to_str(got_from_file))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_file)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_file)
+            # endregion
+
+            # region From string
+            got_from_str = (
+                our_xmlization
+                .wrapper_from_str(text)
+            )
+            et_from_str = ET.fromstring(our_xmlization.to_str(got_from_str))
+            tests.common_xmlization.remove_redundant_whitespace(et_from_str)
+            tests.common_xmlization.assert_elements_equal(et_concrete, et_from_str)
+            # endregion
+
+
+class TestDuplicateProperty(unittest.TestCase):
+    """Test that a property given more than once is refused."""
+
+    def test_duplicate_property(self) -> None:
+        path = (
+            tests.common.TEST_DATA_DIR
+            / "Xml"
+            / "Expected"
+            / 'someItem'
+            / "minimal.xml"
+        )
+
+        text = path.read_text(encoding="utf-8")
+
+        start = text.find('<name>')
+        if start >= 0:
+            end = text.find('</name>', start)
+            duplicated = text[start:end + 7]
+        else:
+            # The element is written self-closing in the example, an empty list
+            # being the usual reason. We write that very element out ourselves.
+            duplicated = '<name/>'
+
+        insertion_index = text.rfind('</someItem>')
+
+        self.assertGreaterEqual(
+            insertion_index,
+            0,
+            "Expected the recorded example to contain the closing tag "
+            f"</someItem>, but it does not: {path}",
+        )
+
+        broken_text = (
+            text[:insertion_index] + duplicated + text[insertion_index:]
+        )
+
+        with self.assertRaises(our_xmlization.DeserializationException):
+            our_xmlization.some_item_from_str(broken_text)
+
+
+if __name__ == "__main__":
+    unittest.main()
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/common.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/common.py
new file mode 100644
index 000000000..dff28a6ff
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/common.py
@@ -0,0 +1,87 @@
+"""Provide common functions shared among the modules."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import collections.abc
+from typing import (
+    Any,
+    NoReturn,
+    Optional,
+    Sequence
+)
+
+
+def assert_never(value: NoReturn) -> NoReturn:
+    """
+    Signal to mypy to perform an exhaustive matching.
+
+    Please see the following page for more details:
+    https://hakibenita.com/python-mypy-exhaustive-checking
+    """
+    assert False, f"Unhandled value: {value} ({type(value).__name__})"
+
+
+def try_to_cast_to_array_like(
+    value: Any
+) -> Optional[Sequence[Any]]:
+    """
+    Try to cast :paramref:`value` to something like a JSON array.
+
+    A mapping and a set are refused, as neither is a JSON array, and so are
+    a ``str``, a ``bytes`` and a ``bytearray``, which Python counts among
+    the sequences but JSON does not.
+
+    Only a sequence is admitted, and never an arbitrary iterable. A one-shot
+    iterable such as a generator is spent by the first walk over it, so
+    a verification followed by a serialization would silently give an empty
+    array -- this function is the single place where all the modules agree on
+    what an array is, so the refusal has to hold for all of them.
+
+    >>> assert try_to_cast_to_array_like(True) is None
+
+    >>> assert try_to_cast_to_array_like(0) is None
+
+    >>> assert try_to_cast_to_array_like(2.2) is None
+
+    >>> assert try_to_cast_to_array_like("hello") is None
+
+    >>> assert try_to_cast_to_array_like(b"hello") is None
+
+    >>> try_to_cast_to_array_like([1, 2])
+    [1, 2]
+
+    >>> assert try_to_cast_to_array_like({"a": 3}) is None
+
+    >>> assert try_to_cast_to_array_like(collections.OrderedDict()) is None
+
+    >>> try_to_cast_to_array_like(range(1, 2))
+    range(1, 2)
+
+    >>> try_to_cast_to_array_like((1, 2))
+    (1, 2)
+
+    >>> assert try_to_cast_to_array_like({1, 2, 3}) is None
+
+    >>> assert try_to_cast_to_array_like(iter([1, 2])) is None
+    """
+    # NOTE (mristin):
+    # A ``list`` is what :py:mod:`json` gives us, and ``isinstance`` against
+    # a concrete class costs a fraction of ``isinstance`` against the abstract
+    # :py:class:`collections.abc.Sequence`, so we shortcut it here.
+    if isinstance(value, list):
+        return value
+
+    if isinstance(value, (str, bytes, bytearray)):
+        return None
+
+    if isinstance(value, collections.abc.Sequence):
+        return value
+
+    return None
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/constants.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/constants.py
new file mode 100644
index 000000000..e8183cde5
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/constants.py
@@ -0,0 +1,17 @@
+"""Provide constant values of the meta-model."""
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+import sys
+from typing import AbstractSet
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+import dummy.types as our_types
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/jsonization.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/jsonization.py
new file mode 100644
index 000000000..893f7577a
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/jsonization.py
@@ -0,0 +1,1034 @@
+"""
+Provide de/serialization of meta-model classes to/from JSON.
+
+We can not use one-pass deserialization for JSON since the object
+properties do not have fixed order, and hence we can not read
+``modelType`` property ahead of the remaining properties.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import collections.abc
+import json
+import re
+import sys
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Mapping,
+    MutableMapping,
+    Optional,
+    Sequence,
+    Tuple,
+    TypeVar,
+    Union,
+)
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+import dummy.common as our_common
+import dummy.stringification as our_stringification
+import dummy.types as our_types
+
+
+# NOTE (mristin):
+# The SDK defines three of these path vocabularies: this one, the one in
+# :py:mod:`dummy.jsonization`, and the one in
+# :py:mod:`dummy.xmlcommon`.
+# They look alike, and it is tempting to merge them, but they are not
+# interchangeable.
+#
+# Each of them points into a different thing, and every segment carries
+# a back-pointer to the container it stepped through, so the type of that
+# back-pointer differs from one to the next:
+#
+# * This one points into the instances which you built, so a property
+#   segment holds a class of the meta-model.
+# * The jsonization's points into the JSON-able structure being read or
+#   written, so a property segment holds the JSON-able mapping instead:
+#   while a document is being parsed, the instance which the property would
+#   belong to does not exist yet.
+# * The xmlcommon's points into the XML document, where there are no
+#   properties at all, only elements, so it names an element instead.
+#
+# The three also render differently: a path into the instances is a Python
+# access expression, a path into a JSON-able structure starts at the root of
+# the document and carries no leading dot, and a path into an XML document
+# is a relative XPath.
+#
+# Merging them would mean either dropping the back-pointers, which have been
+# part of the public API of this SDK since before these modules were split
+# apart, or defining a single path over the union of all the segment kinds --
+# in which case every consumer would have to handle segments which can never
+# occur in its world. Three small vocabularies which each say exactly what
+# they can say cost less than one large one which lies about its range.
+
+
+class PropertySegment:
+    """Represent a property on a path to the erroneous value."""
+
+    #: Instance that contains the property
+    instance: Final[Mapping[str, Any]]
+
+    #: Name of the property
+    name: Final[str]
+
+    def __init__(
+            self,
+            instance: Mapping[str, Any],
+            name: str
+    ) -> None:
+        """Initialize with the given values."""
+        self.instance = instance
+        self.name = name
+
+
+class IndexSegment:
+    """Represent an index access on a path to the erroneous value."""
+
+    #: Container that contains the item
+    container: Final[Iterable[Any]]
+
+    #: Index of the item
+    index: Final[int]
+
+    def __init__(
+            self,
+            container: Iterable[Any],
+            index: int
+    ) -> None:
+        """Initialize with the given values."""
+        self.container = container
+        self.index = index
+
+
+class KeySegment:
+    """
+    Represent a member access on a path to the erroneous value.
+
+    Unlike a :py:class:`PropertySegment`, which names a property of one of our
+    classes, a key names a member of an open JSON-able object. It is known only
+    at run time, and can be any string at all, so it is always rendered
+    as a subscript.
+    """
+
+    #: Mapping that contains the value at :py:attr:`~key`
+    mapping: Final[Mapping[str, Any]]
+
+    #: Key of the value
+    key: Final[str]
+
+    def __init__(
+            self,
+            mapping: Mapping[str, Any],
+            key: str
+    ) -> None:
+        """Initialize with the given values."""
+        self.mapping = mapping
+        self.key = key
+
+
+Segment = Union[PropertySegment, IndexSegment, KeySegment]
+
+
+#: Match the property names which a path writes after a dot; the other names
+#: are written in brackets as JSON strings, *e.g.*, ``["$eq"]``.
+_VARIABLE_NAME_RE = re.compile(r"^[a-zA-Z_][a-zA-Z_0-9]*$")
+
+
+class Path:
+    """Represent the relative path to the erroneous value."""
+
+    def __init__(self) -> None:
+        """Initialize as an empty path."""
+        self._segments = []  # type: List[Segment]
+
+    @property
+    def segments(self) -> Sequence[Segment]:
+        """Get the segments of the path."""
+        return self._segments
+
+    def _prepend(self, segment: Segment) -> None:
+        """Insert the :paramref:`segment` in front of other segments."""
+        self._segments.insert(0, segment)
+
+    def __str__(self) -> str:
+        if len(self._segments) == 0:
+            return ""
+
+        parts = []  # type: List[str]
+
+        iterator = iter(self._segments)
+        first = next(iterator)
+        if isinstance(first, PropertySegment):
+            if _VARIABLE_NAME_RE.match(first.name):
+                parts.append(first.name)
+            else:
+                parts.append(f"[{json.dumps(first.name, ensure_ascii=False)}]")
+        elif isinstance(first, IndexSegment):
+            parts.append(f"[{first.index}]")
+        elif isinstance(first, KeySegment):
+            parts.append(f"[{json.dumps(first.key, ensure_ascii=False)}]")
+        else:
+            our_common.assert_never(first)
+
+        for segment in iterator:
+            if isinstance(segment, PropertySegment):
+                if _VARIABLE_NAME_RE.match(segment.name):
+                    parts.append(f".{segment.name}")
+                else:
+                    parts.append(f"[{json.dumps(segment.name, ensure_ascii=False)}]")
+            elif isinstance(segment, IndexSegment):
+                parts.append(f"[{segment.index}]")
+            elif isinstance(segment, KeySegment):
+                parts.append(f"[{json.dumps(segment.key, ensure_ascii=False)}]")
+            else:
+                our_common.assert_never(segment)
+
+        return "".join(parts)
+
+
+class DeserializationException(Exception):
+    """Signal that the JSON de-serialization could not be performed."""
+
+    #: Human-readable explanation of the exception's cause
+    cause: Final[str]
+
+    #: Relative path to the erroneous value
+    path: Final[Path]
+
+    def __init__(
+            self,
+            cause: str
+    ) -> None:
+        """Initialize with the given :paramref:`cause` and an empty path."""
+        self.cause = cause
+        self.path = Path()
+
+
+# NOTE (mristin):
+# Recursive definitions are not yet available in mypy
+# (see https://github.com/python/mypy/issues/731). We have to use ``Any``
+# here, instead of recursive type annotations.
+Jsonable = Union[
+    bool,
+    int,
+    float,
+    str,
+    Sequence[Any],
+    Mapping[str, Any]
+]
+
+
+MutableJsonable = Union[
+    bool,
+    int,
+    float,
+    str,
+    List[Any],
+    MutableMapping[str, Any]
+]
+
+
+# region De-serialization
+
+
+_ValueT = TypeVar("_ValueT")
+
+#: Parse a JSON-able value into a value of the meta-model
+_Parser = Callable[
+    [Jsonable],
+    _ValueT
+]
+
+
+def _as_mapping(
+    jsonable: Jsonable
+) -> Mapping[str, Any]:
+    """
+    Interpret :paramref:`jsonable` as a mapping.
+
+    :param jsonable: JSON-able structure to be interpreted
+    :return: :paramref:`jsonable`, as a mapping
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    # NOTE (mristin):
+    # We check against ``dict`` first. That is what :py:mod:`json` gives us, and
+    # ``isinstance`` against a concrete class costs a fraction of ``isinstance``
+    # against the abstract :py:class:`collections.abc.Mapping` -- measured on
+    # CPython 3.10, 59 ns against 274 ns -- on a check which runs once for every
+    # instance that we de-serialize.
+    #
+    # We give the mapping back, instead of only raising, so that the caller can
+    # go on with a narrowed type. ``mypy --strict`` does not narrow a union
+    # across a call which merely raises.
+    if (
+        not isinstance(jsonable, dict)
+        and not isinstance(jsonable, collections.abc.Mapping)
+    ):
+        raise DeserializationException(
+            f"Expected a mapping, but got: {type(jsonable)}"
+        )
+
+    return jsonable
+
+
+def _dispatch_from_jsonable(
+    jsonable: Jsonable,
+    dispatch: Mapping[str, _Parser[_ValueT]],
+    name: str
+) -> _ValueT:
+    """
+    Parse :paramref:`jsonable` by dispatching on its ``modelType``.
+
+    :param jsonable: JSON-able structure to be parsed
+    :param dispatch: to parse a concrete instance, by its model type
+    :param name: of the parsed type, for the error message
+    :return: parsed instance
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    mapping = _as_mapping(jsonable)
+
+    model_type = mapping.get("modelType", None)
+    if model_type is None:
+        raise DeserializationException(
+            "Expected the property modelType, but found none"
+        )
+
+    if not isinstance(model_type, str):
+        # NOTE (mristin):
+        # A model type of a wrong type is reported at the property, as the type
+        # errors of all the other properties are.
+        exception = DeserializationException(
+            f"Expected the property modelType to be a str, "
+            f"but got: {type(model_type)}"
+        )
+        exception.path._prepend(PropertySegment(mapping, "modelType"))
+        raise exception
+
+    parse = dispatch.get(model_type, None)
+    if parse is None:
+        raise DeserializationException(
+            f"Unexpected model type for {name}: {model_type}"
+        )
+
+    return parse(mapping)
+
+
+def _int_from_jsonable(
+    jsonable: Jsonable
+) -> int:
+    """
+    Parse :paramref:`jsonable` as an integer.
+
+    :param jsonable: JSON-able structure to be parsed
+    :return: parsed integer
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    # NOTE (mristin):
+    # ``bool`` is a subclass of ``int`` in Python, so it has to be excluded
+    # explicitly. Otherwise ``True`` would be read as ``1``.
+    if isinstance(jsonable, bool) or not isinstance(jsonable, int):
+        raise DeserializationException(
+            f"Expected an int, but got: {type(jsonable)}"
+        )
+    return jsonable
+
+
+def _str_from_jsonable(
+    jsonable: Jsonable
+) -> str:
+    """
+    Parse :paramref:`jsonable` as a string.
+
+    :param jsonable: JSON-able structure to be parsed
+    :return: parsed string
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    if not isinstance(jsonable, str):
+        raise DeserializationException(
+            f"Expected a str, but got: {type(jsonable)}"
+        )
+    return jsonable
+
+
+def _list_from_jsonable(
+    jsonable: Jsonable,
+    parse_item: _Parser[_ValueT]
+) -> List[_ValueT]:
+    """
+    Parse :paramref:`jsonable` as a list, applying :paramref:`parse_item` on
+    every item.
+
+    :param jsonable: JSON-able structure to be parsed
+    :param parse_item: to parse a single item of the array
+    :return: parsed list
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    array_like = our_common.try_to_cast_to_array_like(jsonable)
+    if array_like is None:
+        raise DeserializationException(
+            f"Expected something array-like, but got: {type(jsonable)}"
+        )
+
+    result = []  # type: List[_ValueT]
+    for i, jsonable_item in enumerate(array_like):
+        try:
+            item = parse_item(jsonable_item)
+        except DeserializationException as exception:
+            exception.path._prepend(IndexSegment(array_like, i))
+            raise
+
+        result.append(item)
+
+    return result
+
+
+def _list_of__item_from_jsonable(
+    jsonable: Jsonable
+) -> List[our_types.Item]:
+    """
+    Parse :paramref:`jsonable` as a list of
+    :py:class:`.types.Item`.
+
+    :param jsonable: JSON-able structure to be parsed
+    :return: parsed list
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    return _list_from_jsonable(
+        jsonable,
+        item_from_jsonable
+    )
+
+
+def _list_of__some_item_from_jsonable(
+    jsonable: Jsonable
+) -> List[our_types.SomeItem]:
+    """
+    Parse :paramref:`jsonable` as a list of
+    :py:class:`.types.SomeItem`.
+
+    :param jsonable: JSON-able structure to be parsed
+    :return: parsed list
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    return _list_from_jsonable(
+        jsonable,
+        some_item_from_jsonable
+    )
+
+
+def _list_of__special_item_from_jsonable(
+    jsonable: Jsonable
+) -> List[our_types.SpecialItem]:
+    """
+    Parse :paramref:`jsonable` as a list of
+    :py:class:`.types.SpecialItem`.
+
+    :param jsonable: JSON-able structure to be parsed
+    :return: parsed list
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    return _list_from_jsonable(
+        jsonable,
+        special_item_from_jsonable
+    )
+
+
+def item_from_jsonable(
+        jsonable: Jsonable
+) -> our_types.Item:
+    """
+    Parse an instance of :py:class:`.types.Item` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Concrete instance of :py:class:`.types.Item`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    return _dispatch_from_jsonable(
+        jsonable,
+        _ITEM_FROM_JSONABLE_DISPATCH,
+        'Item'
+    )
+
+
+def some_item_from_jsonable(
+        jsonable: Jsonable
+) -> our_types.SomeItem:
+    """
+    Parse an instance of :py:class:`.types.SomeItem` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Concrete instance of :py:class:`.types.SomeItem`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    return _dispatch_from_jsonable(
+        jsonable,
+        _SOME_ITEM_FROM_JSONABLE_DISPATCH,
+        'SomeItem'
+    )
+
+
+def _some_item_from_jsonable_without_dispatch(
+        jsonable: Jsonable
+) -> our_types.SomeItem:
+    """
+    Parse an instance of :py:class:`.types.SomeItem` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    This function performs no dispatch! It is used to parse the properties
+    as-are, and already assumes the exact model type. Usually, this function
+    is called from within a dispatching function, and you never call it
+    directly. If you want to de-serialize an instance of
+    :py:class:`.types.SomeItem`, call
+    :py:func:`some_item_from_jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Parsed instance of :py:class:`.types.SomeItem`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    mapping = _as_mapping(jsonable)
+
+    the_name: Optional[str] = None
+    the_nickname: Optional[str] = None
+
+    unexpected_key: Optional[str] = None
+
+    try:
+        for key, jsonable_value in mapping.items():
+            if key == 'modelType':
+                # The dispatch has already matched the model type.
+                pass
+            elif key == 'name':
+                the_name = _str_from_jsonable(jsonable_value)
+            elif key == 'nickname':
+                the_nickname = _str_from_jsonable(jsonable_value)
+            else:
+                unexpected_key = key
+                break
+    except DeserializationException as exception:
+        exception.path._prepend(
+            PropertySegment(mapping, key)
+        )
+        raise
+
+    if unexpected_key is not None:
+        raise DeserializationException(
+            f"Unexpected property: {unexpected_key}"
+        )
+
+    if the_name is None:
+        raise DeserializationException(
+            "The required property 'name' is missing"
+        )
+
+    return our_types.SomeItem(
+        the_name,
+        the_nickname
+    )
+
+
+def special_item_from_jsonable(
+        jsonable: Jsonable
+) -> our_types.SpecialItem:
+    """
+    Parse an instance of :py:class:`.types.SpecialItem` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Parsed instance of :py:class:`.types.SpecialItem`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    mapping = _as_mapping(jsonable)
+
+    model_type = mapping.get('modelType', None)
+    if model_type is not None and not isinstance(model_type, str):
+        # NOTE (mristin):
+        # A model type of a wrong type is reported at the property, as the type
+        # errors of all the other properties are.
+        exception = DeserializationException(
+            f"Expected the property modelType to be a str, "
+            f"but got: {type(model_type)}"
+        )
+        exception.path._prepend(PropertySegment(mapping, 'modelType'))
+        raise exception
+
+    if model_type != 'SpecialItem':
+        raise DeserializationException(
+            f"Expected modelType to be 'SpecialItem', "
+            f"but got: {model_type!r}"
+        )
+
+    the_name: Optional[str] = None
+    the_nickname: Optional[str] = None
+    the_level: Optional[int] = None
+
+    unexpected_key: Optional[str] = None
+
+    try:
+        for key, jsonable_value in mapping.items():
+            if key == 'modelType':
+                # The model type has already been checked above.
+                pass
+            elif key == 'name':
+                the_name = _str_from_jsonable(jsonable_value)
+            elif key == 'nickname':
+                the_nickname = _str_from_jsonable(jsonable_value)
+            elif key == 'level':
+                the_level = _int_from_jsonable(jsonable_value)
+            else:
+                unexpected_key = key
+                break
+    except DeserializationException as exception:
+        exception.path._prepend(
+            PropertySegment(mapping, key)
+        )
+        raise
+
+    if unexpected_key is not None:
+        raise DeserializationException(
+            f"Unexpected property: {unexpected_key}"
+        )
+
+    if the_name is None:
+        raise DeserializationException(
+            "The required property 'name' is missing"
+        )
+
+    if the_level is None:
+        raise DeserializationException(
+            "The required property 'level' is missing"
+        )
+
+    return our_types.SpecialItem(
+        the_name,
+        the_level,
+        the_nickname
+    )
+
+
+def container_from_jsonable(
+        jsonable: Jsonable
+) -> our_types.Container:
+    """
+    Parse an instance of :py:class:`.types.Container` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Parsed instance of :py:class:`.types.Container`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    mapping = _as_mapping(jsonable)
+
+    the_items: Optional[List[our_types.Item]] = None
+    the_some_items: Optional[List[our_types.SomeItem]] = None
+    the_special_items: Optional[List[our_types.SpecialItem]] = None
+
+    unexpected_key: Optional[str] = None
+
+    try:
+        for key, jsonable_value in mapping.items():
+            if key == 'items':
+                the_items = _list_of__item_from_jsonable(jsonable_value)
+            elif key == 'someItems':
+                the_some_items = _list_of__some_item_from_jsonable(jsonable_value)
+            elif key == 'specialItems':
+                the_special_items = _list_of__special_item_from_jsonable(jsonable_value)
+            else:
+                unexpected_key = key
+                break
+    except DeserializationException as exception:
+        exception.path._prepend(
+            PropertySegment(mapping, key)
+        )
+        raise
+
+    if unexpected_key is not None:
+        raise DeserializationException(
+            f"Unexpected property: {unexpected_key}"
+        )
+
+    if the_items is None:
+        raise DeserializationException(
+            "The required property 'items' is missing"
+        )
+
+    if the_some_items is None:
+        raise DeserializationException(
+            "The required property 'someItems' is missing"
+        )
+
+    return our_types.Container(
+        the_items,
+        the_some_items,
+        the_special_items
+    )
+
+
+def wrapper_from_jsonable(
+        jsonable: Jsonable
+) -> our_types.Wrapper:
+    """
+    Parse an instance of :py:class:`.types.Wrapper` from the JSON-able
+    structure :paramref:`jsonable`.
+
+    :param jsonable: structure to be parsed
+    :return: Parsed instance of :py:class:`.types.Wrapper`
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`jsonable`
+    """
+    mapping = _as_mapping(jsonable)
+
+    the_container: Optional[our_types.Container] = None
+
+    unexpected_key: Optional[str] = None
+
+    try:
+        for key, jsonable_value in mapping.items():
+            if key == 'container':
+                the_container = container_from_jsonable(jsonable_value)
+            else:
+                unexpected_key = key
+                break
+    except DeserializationException as exception:
+        exception.path._prepend(
+            PropertySegment(mapping, key)
+        )
+        raise
+
+    if unexpected_key is not None:
+        raise DeserializationException(
+            f"Unexpected property: {unexpected_key}"
+        )
+
+    if the_container is None:
+        raise DeserializationException(
+            "The required property 'container' is missing"
+        )
+
+    return our_types.Wrapper(
+        the_container
+    )
+
+
+#: De-serialize a concrete instance of
+#: :py:class:`.types.Item`, by its model type
+_ITEM_FROM_JSONABLE_DISPATCH: Mapping[
+    str,
+    _Parser[our_types.Item]
+] = {
+    'SomeItem': some_item_from_jsonable,
+    'SpecialItem': special_item_from_jsonable,
+}
+
+
+#: De-serialize a concrete instance of
+#: :py:class:`.types.SomeItem`, by its model type
+_SOME_ITEM_FROM_JSONABLE_DISPATCH: Mapping[
+    str,
+    _Parser[our_types.SomeItem]
+] = {
+    'SomeItem': _some_item_from_jsonable_without_dispatch,
+    'SpecialItem': special_item_from_jsonable,
+}
+
+
+# endregion
+
+
+# region Serialization
+
+
+class SerializationException(Exception):
+    """Signal that the JSON serialization could not be performed."""
+
+    #: Human-readable explanation of the exception's cause
+    cause: Final[str]
+
+    def __init__(
+            self,
+            cause: str
+    ) -> None:
+        """Initialize with the given :paramref:`cause` and an empty path."""
+        self.cause = cause
+        self._segments = []  # type: List[str]
+
+    @property
+    def path(self) -> str:
+        """
+        Render the path to the erroneous value as a Python access expression.
+
+        The path points into the instance which you handed over for
+        the serialization, and *not* into a JSON document -- at the point of
+        the failure, there is no document yet. For example, ``.submodels[0].value``
+        tells you that the serialization broke on ``that.submodels[0].value``.
+        """
+        return ''.join(self._segments)
+
+    def _prepend_property(self, name: str) -> None:
+        """Insert the access to the property :paramref:`name` before the path."""
+        self._segments.insert(0, f'.{name}')
+
+    def _prepend_index(self, index: int) -> None:
+        """Insert the access to the item at :paramref:`index` before the path."""
+        self._segments.insert(0, f'[{index}]')
+
+    def _prepend_key(self, key: str) -> None:
+        """
+        Insert the access to the member :paramref:`key` before the path.
+
+        Unlike a property of one of our classes, a member of an open JSON-able
+        object is known only at run time and can be any string at all, so it is
+        always rendered as a subscript.
+        """
+        self._segments.insert(0, f'[{json.dumps(key, ensure_ascii=False)}]')
+
+    def __str__(self) -> str:
+        if len(self._segments) == 0:
+            return self.cause
+
+        return f'{self.path}: {self.cause}'
+
+
+def _int_to_jsonable(
+    that: int
+) -> int:
+    """
+    Serialize :paramref:`that` integer to a JSON-able value.
+
+    Only the integers in the range :math:`[-2^{53} + 1, 2^{53} - 1]` are
+    serialized. Outside of it, an integer can not be exactly represented as
+    a 64-bit floating-point number, which is what the JSON de-serializers of
+    the other languages read a number into.
+
+    :param that: integer to be serialized
+    :return: :paramref:`that`, unchanged
+    :raise: :py:class:`SerializationException` if outside the range
+    """
+    if that < -9007199254740991 or that > 9007199254740991:
+        raise SerializationException(
+            f"The integer can not be serialized to JSON as it is outside "
+            f"the range [-2^53 + 1, 2^53 - 1]: {that}"
+        )
+    return that
+
+
+def _list_of__item_to_jsonable(
+    that: List[our_types.Item]
+) -> List[MutableJsonable]:
+    """
+    Serialize :paramref:`that` as a list of
+    :py:class:`.types.Item`.
+
+    :param that: list to be serialized
+    :return: JSON-able representation of :paramref:`that`
+    """
+    jsonable = []  # type: List[MutableJsonable]
+    for i, item in enumerate(that):
+        try:
+            jsonable.append(
+                item.transform(_SERIALIZER)
+            )
+        except SerializationException as exception:
+            exception._prepend_index(i)
+            raise
+    return jsonable
+
+
+def _list_of__some_item_to_jsonable(
+    that: List[our_types.SomeItem]
+) -> List[MutableJsonable]:
+    """
+    Serialize :paramref:`that` as a list of
+    :py:class:`.types.SomeItem`.
+
+    :param that: list to be serialized
+    :return: JSON-able representation of :paramref:`that`
+    """
+    jsonable = []  # type: List[MutableJsonable]
+    for i, item in enumerate(that):
+        try:
+            jsonable.append(
+                item.transform(_SERIALIZER)
+            )
+        except SerializationException as exception:
+            exception._prepend_index(i)
+            raise
+    return jsonable
+
+
+def _list_of__special_item_to_jsonable(
+    that: List[our_types.SpecialItem]
+) -> List[MutableJsonable]:
+    """
+    Serialize :paramref:`that` as a list of
+    :py:class:`.types.SpecialItem`.
+
+    :param that: list to be serialized
+    :return: JSON-able representation of :paramref:`that`
+    """
+    jsonable = []  # type: List[MutableJsonable]
+    for i, item in enumerate(that):
+        try:
+            jsonable.append(
+                _special_item_to_jsonable(
+                    item
+                )
+            )
+        except SerializationException as exception:
+            exception._prepend_index(i)
+            raise
+    return jsonable
+
+
+def _some_item_to_jsonable(
+    that: our_types.SomeItem
+) -> MutableMapping[str, MutableJsonable]:
+    """Serialize :paramref:`that` to a JSON-able representation."""
+    jsonable: MutableMapping[str, MutableJsonable] = dict()
+    try:
+        jsonable['name'] = that.name
+    except SerializationException as exception:
+        exception._prepend_property('name')
+        raise
+    if that.nickname is not None:
+        try:
+            jsonable['nickname'] = that.nickname
+        except SerializationException as exception:
+            exception._prepend_property('nickname')
+            raise
+    jsonable['modelType'] = 'SomeItem'
+    return jsonable
+
+
+def _special_item_to_jsonable(
+    that: our_types.SpecialItem
+) -> MutableMapping[str, MutableJsonable]:
+    """Serialize :paramref:`that` to a JSON-able representation."""
+    jsonable: MutableMapping[str, MutableJsonable] = dict()
+    try:
+        jsonable['name'] = that.name
+    except SerializationException as exception:
+        exception._prepend_property('name')
+        raise
+    if that.nickname is not None:
+        try:
+            jsonable['nickname'] = that.nickname
+        except SerializationException as exception:
+            exception._prepend_property('nickname')
+            raise
+    try:
+        jsonable['level'] = _int_to_jsonable(
+            that.level
+        )
+    except SerializationException as exception:
+        exception._prepend_property('level')
+        raise
+    jsonable['modelType'] = 'SpecialItem'
+    return jsonable
+
+
+def _container_to_jsonable(
+    that: our_types.Container
+) -> MutableMapping[str, MutableJsonable]:
+    """Serialize :paramref:`that` to a JSON-able representation."""
+    jsonable: MutableMapping[str, MutableJsonable] = dict()
+    try:
+        jsonable['items'] = _list_of__item_to_jsonable(
+            that.items
+        )
+    except SerializationException as exception:
+        exception._prepend_property('items')
+        raise
+    try:
+        jsonable['someItems'] = _list_of__some_item_to_jsonable(
+            that.some_items
+        )
+    except SerializationException as exception:
+        exception._prepend_property('some_items')
+        raise
+    if that.special_items is not None:
+        try:
+            jsonable['specialItems'] = _list_of__special_item_to_jsonable(
+                that.special_items
+            )
+        except SerializationException as exception:
+            exception._prepend_property('special_items')
+            raise
+    return jsonable
+
+
+def _wrapper_to_jsonable(
+    that: our_types.Wrapper
+) -> MutableMapping[str, MutableJsonable]:
+    """Serialize :paramref:`that` to a JSON-able representation."""
+    jsonable: MutableMapping[str, MutableJsonable] = dict()
+    try:
+        jsonable['container'] = _container_to_jsonable(
+            that.container
+        )
+    except SerializationException as exception:
+        exception._prepend_property('container')
+        raise
+    return jsonable
+
+
+class _Serializer(
+        our_types.AbstractTransformer[MutableJsonable]
+):
+    """
+    Dispatch on the class of an instance to serialize it.
+
+    The methods *are* the serializers, instead of forwarding to them, so that
+    a dispatch costs a single call. Wherever the class of a value is already
+    known -- which is every class without concrete descendants -- the serializer
+    is called directly and this transformer is not involved at all.
+    """
+
+    transform_some_item = staticmethod(
+        _some_item_to_jsonable
+    )
+    transform_special_item = staticmethod(
+        _special_item_to_jsonable
+    )
+    transform_container = staticmethod(
+        _container_to_jsonable
+    )
+    transform_wrapper = staticmethod(
+        _wrapper_to_jsonable
+    )
+
+
+_SERIALIZER = _Serializer()
+
+
+def to_jsonable(that: our_types.Class) -> MutableJsonable:
+    """
+    Convert :paramref:`that` to a JSON-able structure.
+
+    :param that:
+        Model instance to be recursively converted to a JSON-able structure
+    :return:
+        JSON-able structure which can be further encoded with, *e.g.*, :py:mod:`json`
+    :raise:
+        :py:class:`SerializationException` if :paramref:`that` contains a number
+        which JSON can not represent
+    """
+    return that.transform(_SERIALIZER)
+
+
+# endregion
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/reporting.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/reporting.py
new file mode 100644
index 000000000..c36fbc039
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/reporting.py
@@ -0,0 +1,191 @@
+"""
+Report where in the data an error lies.
+
+A path is a sequence of segments which lead from the instance you handed over
+down to the erroneous value. It renders as a Python access expression, so that
+you can paste it as it stands:
+
+.. code-block::
+
+    .things[1].labels[0]
+
+The vocabulary lives on its own so that
+:py:mod:`dummy.verification`, and the verification of
+a JSON-able value where the meta-model has one, report with the very same
+classes.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import collections
+import json
+import sys
+from typing import (
+    Any,
+    Deque,
+    Mapping,
+    Sequence,
+    Union
+)
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+import dummy.types as our_types
+
+
+# NOTE (mristin):
+# The SDK defines three of these path vocabularies: this one, the one in
+# :py:mod:`dummy.jsonization`, and the one in
+# :py:mod:`dummy.xmlcommon`.
+# They look alike, and it is tempting to merge them, but they are not
+# interchangeable.
+#
+# Each of them points into a different thing, and every segment carries
+# a back-pointer to the container it stepped through, so the type of that
+# back-pointer differs from one to the next:
+#
+# * This one points into the instances which you built, so a property
+#   segment holds a class of the meta-model.
+# * The jsonization's points into the JSON-able structure being read or
+#   written, so a property segment holds the JSON-able mapping instead:
+#   while a document is being parsed, the instance which the property would
+#   belong to does not exist yet.
+# * The xmlcommon's points into the XML document, where there are no
+#   properties at all, only elements, so it names an element instead.
+#
+# The three also render differently: a path into the instances is a Python
+# access expression, a path into a JSON-able structure starts at the root of
+# the document and carries no leading dot, and a path into an XML document
+# is a relative XPath.
+#
+# Merging them would mean either dropping the back-pointers, which have been
+# part of the public API of this SDK since before these modules were split
+# apart, or defining a single path over the union of all the segment kinds --
+# in which case every consumer would have to handle segments which can never
+# occur in its world. Three small vocabularies which each say exactly what
+# they can say cost less than one large one which lies about its range.
+
+
+class PropertySegment:
+    """Represent a property access on a path to an erroneous value."""
+
+    #: Instance containing the property
+    instance: Final[our_types.Class]
+
+    #: Name of the property
+    name: Final[str]
+
+    def __init__(
+            self,
+            instance: our_types.Class,
+            name: str
+    ) -> None:
+        """Initialize with the given values."""
+        self.instance = instance
+        self.name = name
+
+    def __str__(self) -> str:
+        return f'.{self.name}'
+
+
+class IndexSegment:
+    """Represent an index access on a path to an erroneous value."""
+
+    #: Sequence containing the item at :py:attr:`~index`
+    sequence: Final[Sequence[Any]]
+
+    #: Index of the item
+    index: Final[int]
+
+    def __init__(
+            self,
+            sequence: Sequence[Any],
+            index: int
+    ) -> None:
+        """Initialize with the given values."""
+        self.sequence = sequence
+        self.index = index
+
+    def __str__(self) -> str:
+        return f'[{self.index}]'
+
+
+class KeySegment:
+    """
+    Represent a member access on a path to an erroneous value.
+
+    Unlike a :py:class:`PropertySegment`, which names a property of one of our
+    classes, a key names a member of an open JSON-able object. It is known only
+    at run time, and can be any string at all, so it is always rendered
+    as a subscript.
+    """
+
+    #: Mapping containing the value at :py:attr:`~key`
+    mapping: Final[Mapping[str, Any]]
+
+    #: Key of the value
+    key: Final[str]
+
+    def __init__(
+            self,
+            mapping: Mapping[str, Any],
+            key: str
+    ) -> None:
+        """Initialize with the given values."""
+        self.mapping = mapping
+        self.key = key
+
+    def __str__(self) -> str:
+        return f'[{json.dumps(self.key, ensure_ascii=False)}]'
+
+
+Segment = Union[PropertySegment, IndexSegment, KeySegment]
+
+
+class Path:
+    """Represent the relative path to the erroneous value."""
+
+    def __init__(self) -> None:
+        """Initialize as an empty path."""
+        # NOTE (mristin):
+        # A path is built as the stack unwinds, so every segment is prepended and
+        # none is ever appended. A list would copy the whole path on each of them,
+        # which makes a path of depth *d* cost *d^2* to build, while a deque
+        # prepends in constant time.
+        self._segments = collections.deque()  # type: Deque[Segment]
+
+    @property
+    def segments(self) -> Sequence[Segment]:
+        """Get the segments of the path."""
+        return self._segments
+
+    def _prepend(self, segment: Segment) -> None:
+        """Insert the :paramref:`segment` in front of other segments."""
+        self._segments.appendleft(segment)
+
+    def __str__(self) -> str:
+        return "".join(str(segment) for segment in self._segments)
+
+
+class Error:
+    """Represent a verification error in the data."""
+
+    #: Human-readable description of the error
+    cause: Final[str]
+
+    #: Path to the erroneous value
+    path: Final[Path]
+
+    def __init__(self, cause: str) -> None:
+        """Initialize as an error with an empty path."""
+        self.cause = cause
+        self.path = Path()
+
+    def __repr__(self) -> str:
+        return f"Error(path={self.path}, cause={self.cause})"
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/stringification.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/stringification.py
new file mode 100644
index 000000000..d7499e6a4
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/stringification.py
@@ -0,0 +1,17 @@
+"""De-serialize enumerations from string representations."""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+from typing import (
+    Mapping,
+    Optional,
+)
+
+import dummy.types as our_types
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/types.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/types.py
new file mode 100644
index 000000000..148cc254b
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/types.py
@@ -0,0 +1,905 @@
+"""
+Test the variance of the containers passed as arguments.
+
+A read-only ``Sequence[...]`` argument of a verification function is generic if its
+items are instances of a class with descendants, so that the sequences of
+the descendants can be passed to it without a copy. The arguments of the methods
+and the mutable ``List[...]`` arguments remain invariant.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import abc
+import enum
+from typing import (
+    Generic,
+    Iterator,
+    Optional,
+    TypeVar,
+    List,
+    Tuple,
+    Sequence
+)
+
+
+T = TypeVar("T")
+ContextT = TypeVar("ContextT")
+
+
+class Class(abc.ABC):
+    """Represent the most general class of the meta-model."""
+    @abc.abstractmethod
+    def descend_once(self) -> Iterator["Class"]:
+        """Iterate over all the instances referenced from this one."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def descend(self) -> Iterator["Class"]:
+        """Iterate recursively over all the instances referenced from this one."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def accept(
+            self,
+            visitor: "AbstractVisitor"
+    ) -> None:
+        """
+        Dispatch the :paramref:`visitor` on this instance.
+
+        :param visitor: to be dispatched
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def accept_with_context(
+            self,
+            visitor: "AbstractVisitorWithContext[ContextT]",
+            context: ContextT
+    ) -> None:
+        """
+        Dispatch the :paramref:`visitor` on this instance with :paramref:`context`.
+
+        :param visitor: to be dispatched
+        :param context: of the visitation
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform(
+            self,
+            transformer: "AbstractTransformer[T]"
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance.
+
+        :param transformer: to be dispatched
+        :return: transformed self
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_with_context(
+            self,
+            transformer: "AbstractTransformerWithContext[ContextT, T]",
+            context: ContextT
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance with :paramref:`context`.
+
+        :param transformer: to be dispatched
+        :return: transformed self
+        """
+        raise NotImplementedError()
+
+
+# pylint: disable=redefined-builtin
+
+
+class Item(Class):
+    # pylint: disable=missing-class-docstring
+
+    name: str
+
+    nickname: Optional[str]
+
+    def __init__(
+            self,
+            name: str,
+            nickname: Optional[str] = None
+    ) -> None:
+        """Initialize with the given values."""
+        self.name = name
+        self.nickname = nickname
+
+
+class SomeItem(Item):
+    # pylint: disable=missing-class-docstring
+
+    def descend_once(self) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this instance.
+
+        We do not recurse into the referenced instance.
+
+        :yield: instances directly referenced from this instance
+        """
+        return self._descend(recurse=False)
+
+    def descend(self) -> Iterator[Class]:
+        """
+        Iterate recursively over the instances referenced from this one.
+
+        :yield: instances recursively referenced from this instance
+        """
+        return self._descend(recurse=True)
+
+    def _descend(self, recurse: bool) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this one, and recursively
+        over their descendants if :paramref:`recurse` is set.
+
+        :param recurse: if set, descend recursively into the referenced instances
+        :yield: instances referenced from this instance
+        """
+        # No descendable properties
+        return
+        # For this uncommon return-yield construction, see:
+        # https://stackoverflow.com/questions/13243766/how-to-define-an-empty-generator-function
+        # noinspection PyUnreachableCode
+        yield
+
+    def accept(self, visitor: "AbstractVisitor") -> None:
+        """Dispatch the :paramref:`visitor` on this instance."""
+        visitor.visit_some_item(self)
+
+    def accept_with_context(
+            self,
+            visitor: "AbstractVisitorWithContext[ContextT]",
+            context: ContextT
+    ) -> None:
+        """Dispatch the :paramref:`visitor` on this instance in :paramref:`context`."""
+        visitor.visit_some_item_with_context(self, context)
+
+    def transform(
+            self,
+            transformer: "AbstractTransformer[T]"
+    ) -> T:
+        """Dispatch the :paramref:`transformer` on this instance."""
+        return transformer.transform_some_item(self)
+
+    def transform_with_context(
+            self,
+            transformer: "AbstractTransformerWithContext[ContextT, T]",
+            context: ContextT
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance in :paramref:`context`.
+        """
+        return transformer.transform_some_item_with_context(
+            self, context)
+
+    def __init__(
+            self,
+            name: str,
+            nickname: Optional[str] = None
+    ) -> None:
+        """Initialize with the given values."""
+        Item.__init__(
+            self,
+            name,
+            nickname
+        )
+
+
+class SpecialItem(SomeItem):
+    # pylint: disable=missing-class-docstring
+
+    level: int
+
+    def descend_once(self) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this instance.
+
+        We do not recurse into the referenced instance.
+
+        :yield: instances directly referenced from this instance
+        """
+        return self._descend(recurse=False)
+
+    def descend(self) -> Iterator[Class]:
+        """
+        Iterate recursively over the instances referenced from this one.
+
+        :yield: instances recursively referenced from this instance
+        """
+        return self._descend(recurse=True)
+
+    def _descend(self, recurse: bool) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this one, and recursively
+        over their descendants if :paramref:`recurse` is set.
+
+        :param recurse: if set, descend recursively into the referenced instances
+        :yield: instances referenced from this instance
+        """
+        # No descendable properties
+        return
+        # For this uncommon return-yield construction, see:
+        # https://stackoverflow.com/questions/13243766/how-to-define-an-empty-generator-function
+        # noinspection PyUnreachableCode
+        yield
+
+    def accept(self, visitor: "AbstractVisitor") -> None:
+        """Dispatch the :paramref:`visitor` on this instance."""
+        visitor.visit_special_item(self)
+
+    def accept_with_context(
+            self,
+            visitor: "AbstractVisitorWithContext[ContextT]",
+            context: ContextT
+    ) -> None:
+        """Dispatch the :paramref:`visitor` on this instance in :paramref:`context`."""
+        visitor.visit_special_item_with_context(self, context)
+
+    def transform(
+            self,
+            transformer: "AbstractTransformer[T]"
+    ) -> T:
+        """Dispatch the :paramref:`transformer` on this instance."""
+        return transformer.transform_special_item(self)
+
+    def transform_with_context(
+            self,
+            transformer: "AbstractTransformerWithContext[ContextT, T]",
+            context: ContextT
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance in :paramref:`context`.
+        """
+        return transformer.transform_special_item_with_context(
+            self, context)
+
+    def __init__(
+            self,
+            name: str,
+            level: int,
+            nickname: Optional[str] = None
+    ) -> None:
+        """Initialize with the given values."""
+        SomeItem.__init__(
+            self,
+            name,
+            nickname
+        )
+        self.level = level
+
+
+class Container(Class):
+    # pylint: disable=missing-class-docstring
+
+    items: List['Item']
+
+    some_items: List['SomeItem']
+
+    special_items: Optional[List['SpecialItem']]
+
+    def over_special_items_or_empty(
+            self
+    ) -> Iterator['SpecialItem']:
+        """Yield from :py:attr:`.special_items` if set."""
+        if self.special_items is not None:
+            yield from self.special_items
+
+    def count_items(
+        self,
+        items: Sequence['Item']
+    ) -> int:
+        """
+        Count the :paramref:`items`.
+
+        The arguments of the methods are never generic, so only the sequences of
+        :py:class:`Item` can be passed to it, but not the sequences of
+        the descendants.
+        """
+        # pylint: disable=all
+        return len(items)
+
+    def descend_once(self) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this instance.
+
+        We do not recurse into the referenced instance.
+
+        :yield: instances directly referenced from this instance
+        """
+        return self._descend(recurse=False)
+
+    def descend(self) -> Iterator[Class]:
+        """
+        Iterate recursively over the instances referenced from this one.
+
+        :yield: instances recursively referenced from this instance
+        """
+        return self._descend(recurse=True)
+
+    def _descend(self, recurse: bool) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this one, and recursively
+        over their descendants if :paramref:`recurse` is set.
+
+        :param recurse: if set, descend recursively into the referenced instances
+        :yield: instances referenced from this instance
+        """
+        yield from _descend_list_of__item(self.items, recurse)
+
+        yield from _descend_list_of__some_item(self.some_items, recurse)
+
+        if self.special_items is not None:
+            yield from _descend_list_of__special_item(self.special_items, recurse)
+
+    def accept(self, visitor: "AbstractVisitor") -> None:
+        """Dispatch the :paramref:`visitor` on this instance."""
+        visitor.visit_container(self)
+
+    def accept_with_context(
+            self,
+            visitor: "AbstractVisitorWithContext[ContextT]",
+            context: ContextT
+    ) -> None:
+        """Dispatch the :paramref:`visitor` on this instance in :paramref:`context`."""
+        visitor.visit_container_with_context(self, context)
+
+    def transform(
+            self,
+            transformer: "AbstractTransformer[T]"
+    ) -> T:
+        """Dispatch the :paramref:`transformer` on this instance."""
+        return transformer.transform_container(self)
+
+    def transform_with_context(
+            self,
+            transformer: "AbstractTransformerWithContext[ContextT, T]",
+            context: ContextT
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance in :paramref:`context`.
+        """
+        return transformer.transform_container_with_context(
+            self, context)
+
+    def __init__(
+            self,
+            items: List['Item'],
+            some_items: List['SomeItem'],
+            special_items: Optional[List['SpecialItem']] = None
+    ) -> None:
+        """Initialize with the given values."""
+        self.items = items
+        self.some_items = some_items
+        self.special_items = special_items
+
+
+class Wrapper(Class):
+    # pylint: disable=missing-class-docstring
+
+    container: 'Container'
+
+    def descend_once(self) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this instance.
+
+        We do not recurse into the referenced instance.
+
+        :yield: instances directly referenced from this instance
+        """
+        return self._descend(recurse=False)
+
+    def descend(self) -> Iterator[Class]:
+        """
+        Iterate recursively over the instances referenced from this one.
+
+        :yield: instances recursively referenced from this instance
+        """
+        return self._descend(recurse=True)
+
+    def _descend(self, recurse: bool) -> Iterator[Class]:
+        """
+        Iterate over the instances referenced from this one, and recursively
+        over their descendants if :paramref:`recurse` is set.
+
+        :param recurse: if set, descend recursively into the referenced instances
+        :yield: instances referenced from this instance
+        """
+        yield self.container
+
+        if recurse:
+            yield from self.container.descend()
+
+    def accept(self, visitor: "AbstractVisitor") -> None:
+        """Dispatch the :paramref:`visitor` on this instance."""
+        visitor.visit_wrapper(self)
+
+    def accept_with_context(
+            self,
+            visitor: "AbstractVisitorWithContext[ContextT]",
+            context: ContextT
+    ) -> None:
+        """Dispatch the :paramref:`visitor` on this instance in :paramref:`context`."""
+        visitor.visit_wrapper_with_context(self, context)
+
+    def transform(
+            self,
+            transformer: "AbstractTransformer[T]"
+    ) -> T:
+        """Dispatch the :paramref:`transformer` on this instance."""
+        return transformer.transform_wrapper(self)
+
+    def transform_with_context(
+            self,
+            transformer: "AbstractTransformerWithContext[ContextT, T]",
+            context: ContextT
+    ) -> T:
+        """
+        Dispatch the :paramref:`transformer` on this instance in :paramref:`context`.
+        """
+        return transformer.transform_wrapper_with_context(
+            self, context)
+
+    def __init__(self, container: 'Container') -> None:
+        """Initialize with the given values."""
+        self.container = container
+
+
+def _descend_list_of__item(
+        that: List['Item'],
+        recurse: bool
+) -> Iterator[Class]:
+    """
+    Iterate over the instances held by :paramref:`that`.
+
+    If :paramref:`recurse` is set, descend recursively into the instances
+    as well.
+    """
+    if not recurse:
+        yield from that
+        return
+
+    for item in that:
+        yield item
+
+        yield from item.descend()
+
+
+def _descend_list_of__some_item(
+        that: List['SomeItem'],
+        recurse: bool
+) -> Iterator[Class]:
+    """
+    Iterate over the instances held by :paramref:`that`.
+
+    If :paramref:`recurse` is set, descend recursively into the instances
+    as well.
+    """
+    if not recurse:
+        yield from that
+        return
+
+    for item in that:
+        yield item
+
+        yield from item.descend()
+
+
+def _descend_list_of__special_item(
+        that: List['SpecialItem'],
+        recurse: bool
+) -> Iterator[Class]:
+    """
+    Iterate over the instances held by :paramref:`that`.
+
+    If :paramref:`recurse` is set, descend recursively into the instances
+    as well.
+    """
+    if not recurse:
+        yield from that
+        return
+
+    for item in that:
+        yield item
+
+        yield from item.descend()
+
+
+class AbstractVisitor:
+    """Visit the instances of the model."""
+    def visit(
+            self,
+            that: Class
+    ) -> None:
+        """Double-dispatch on :paramref:`that`."""
+        that.accept(self)
+
+    @abc.abstractmethod
+    def visit_some_item(
+            self,
+            that: SomeItem
+    ) -> None:
+        """Visit :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_special_item(
+            self,
+            that: SpecialItem
+    ) -> None:
+        """Visit :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_container(
+            self,
+            that: Container
+    ) -> None:
+        """Visit :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_wrapper(
+            self,
+            that: Wrapper
+    ) -> None:
+        """Visit :paramref:`that`."""
+        raise NotImplementedError()
+
+
+class AbstractVisitorWithContext(Generic[ContextT]):
+    """Visit the instances of the model with context."""
+    def visit_with_context(
+            self,
+            that: Class,
+            context: ContextT
+    ) -> None:
+        """Double-dispatch on :paramref:`that`."""
+        that.accept_with_context(self, context)
+
+    @abc.abstractmethod
+    def visit_some_item_with_context(
+            self,
+            that: SomeItem,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_special_item_with_context(
+            self,
+            that: SpecialItem,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_container_with_context(
+            self,
+            that: Container,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def visit_wrapper_with_context(
+            self,
+            that: Wrapper,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+
+class PassThroughVisitor(AbstractVisitor):
+    """
+    Visit the instances of the model without action.
+
+    This visitor is not meant to be directly used. Instead, you usually
+    inherit from it, and implement only the relevant visit methods.
+    """
+    def visit(
+            self,
+            that: Class
+    ) -> None:
+        """Double-dispatch on :paramref:`that`."""
+        that.accept(self)
+
+    def visit_some_item(
+            self,
+            that: SomeItem
+    ) -> None:
+        """Visit :paramref:`that`."""
+        for another in that.descend_once():
+            self.visit(another)
+
+    def visit_special_item(
+            self,
+            that: SpecialItem
+    ) -> None:
+        """Visit :paramref:`that`."""
+        for another in that.descend_once():
+            self.visit(another)
+
+    def visit_container(
+            self,
+            that: Container
+    ) -> None:
+        """Visit :paramref:`that`."""
+        for another in that.descend_once():
+            self.visit(another)
+
+    def visit_wrapper(
+            self,
+            that: Wrapper
+    ) -> None:
+        """Visit :paramref:`that`."""
+        for another in that.descend_once():
+            self.visit(another)
+
+
+class PassThroughVisitorWithContext(
+        AbstractVisitorWithContext[ContextT]
+):
+    """
+    Visit the instances of the model without action and in context.
+
+    This visitor is not meant to be directly used. Instead, you usually
+    inherit from it, and implement only the relevant visit methods.
+    """
+    def visit_with_context(
+            self,
+            that: Class,
+            context: ContextT
+    ) -> None:
+        """Double-dispatch on :paramref:`that`."""
+        that.accept_with_context(self, context)
+
+    def visit_some_item_with_context(
+            self,
+            that: SomeItem,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        for another in that.descend_once():
+            self.visit_with_context(another, context)
+
+    def visit_special_item_with_context(
+            self,
+            that: SpecialItem,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        for another in that.descend_once():
+            self.visit_with_context(another, context)
+
+    def visit_container_with_context(
+            self,
+            that: Container,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        for another in that.descend_once():
+            self.visit_with_context(another, context)
+
+    def visit_wrapper_with_context(
+            self,
+            that: Wrapper,
+            context: ContextT
+    ) -> None:
+        """Visit :paramref:`that` in :paramref:`context`."""
+        for another in that.descend_once():
+            self.visit_with_context(another, context)
+
+
+class AbstractTransformer(Generic[T]):
+    """Transform the instances of the model."""
+    def transform(
+            self,
+            that: Class
+    ) -> T:
+        """Double-dispatch on :paramref:`that`."""
+        return that.transform(self)
+
+    @abc.abstractmethod
+    def transform_some_item(
+            self,
+            that: SomeItem
+    ) -> T:
+        """Transform :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_special_item(
+            self,
+            that: SpecialItem
+    ) -> T:
+        """Transform :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_container(
+            self,
+            that: Container
+    ) -> T:
+        """Transform :paramref:`that`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_wrapper(
+            self,
+            that: Wrapper
+    ) -> T:
+        """Transform :paramref:`that`."""
+        raise NotImplementedError()
+
+
+class AbstractTransformerWithContext(
+        Generic[ContextT, T]
+):
+    """Transform the instances of the model in context."""
+    def transform_with_context(
+            self,
+            that: Class,
+            context: ContextT
+    ) -> T:
+        """Double-dispatch on :paramref:`that`."""
+        return that.transform_with_context(self, context)
+
+    @abc.abstractmethod
+    def transform_some_item_with_context(
+            self,
+            that: SomeItem,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_special_item_with_context(
+            self,
+            that: SpecialItem,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_container_with_context(
+            self,
+            that: Container,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def transform_wrapper_with_context(
+            self,
+            that: Wrapper,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        raise NotImplementedError()
+
+
+class TransformerWithDefault(AbstractTransformer[T]):
+    """
+    Transform the instances of the model.
+
+    If you do not override the transformation methods, they simply
+    return :py:attr:`.default`.
+    """
+    #: Default value which is returned if no override of the transformation
+    default: T
+
+    def __init__(self, default: T) -> None:
+        """Initialize with the given :paramref:`default` value."""
+        self.default = default
+
+    def transform(
+            self,
+            that: Class
+    ) -> T:
+        """Double-dispatch on :paramref:`that`."""
+        return that.transform(self)
+
+    def transform_some_item(
+            self,
+            that: SomeItem
+    ) -> T:
+        """Transform :paramref:`that`."""
+        return self.default
+
+    def transform_special_item(
+            self,
+            that: SpecialItem
+    ) -> T:
+        """Transform :paramref:`that`."""
+        return self.default
+
+    def transform_container(
+            self,
+            that: Container
+    ) -> T:
+        """Transform :paramref:`that`."""
+        return self.default
+
+    def transform_wrapper(
+            self,
+            that: Wrapper
+    ) -> T:
+        """Transform :paramref:`that`."""
+        return self.default
+
+
+class TransformerWithDefaultAndContext(
+        AbstractTransformerWithContext[ContextT, T]
+):
+    """
+    Transform the instances of the model in context.
+
+    If you do not override the transformation methods, they simply
+    return :py:attr:`.default`.
+    """
+    #: Default value which is returned if no override of the transformation
+    default: T
+
+    def __init__(self, default: T) -> None:
+        """Initialize with the given :paramref:`default` value."""
+        self.default = default
+
+    def transform_with_context(
+            self,
+            that: Class,
+            context: ContextT
+    ) -> T:
+        """Double-dispatch on :paramref:`that`."""
+        return that.transform_with_context(self, context)
+
+    def transform_some_item_with_context(
+            self,
+            that: SomeItem,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        return self.default
+
+    def transform_special_item_with_context(
+            self,
+            that: SpecialItem,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        return self.default
+
+    def transform_container_with_context(
+            self,
+            that: Container,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        return self.default
+
+    def transform_wrapper_with_context(
+            self,
+            that: Wrapper,
+            context: ContextT
+    ) -> T:
+        """Transform :paramref:`that` in :paramref:`context`."""
+        return self.default
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/verification.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/verification.py
new file mode 100644
index 000000000..762fc85a5
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/verification.py
@@ -0,0 +1,617 @@
+"""
+Verify that the instances of the meta-model satisfy the invariants.
+
+Here is an example how to verify an instance of :py:class:`dummy.types.SomeItem`:
+
+.. code-block::
+
+    import dummy.types as our_types
+    import dummy.verification as our_verification
+
+    an_instance = our_types.SomeItem(
+        # ... some constructor arguments ...
+    )
+
+    for error in our_verification.verify(an_instance):
+        print(f"{error.cause} at: {error.path}")
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import collections.abc
+import math
+import re
+import struct
+import sys
+from typing import (
+    Any,
+    Callable,
+    Iterable,
+    Iterator,
+    List,
+    Mapping,
+    Optional,
+    Pattern,
+    Sequence,
+    Set,
+    Tuple,
+    Union
+)
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+from dummy import (
+    constants as our_constants,
+    reporting as our_reporting,
+    types as our_types,
+)
+
+
+PropertySegment = our_reporting.PropertySegment
+IndexSegment = our_reporting.IndexSegment
+KeySegment = our_reporting.KeySegment
+Segment = our_reporting.Segment
+Path = our_reporting.Path
+
+Error = our_reporting.Error
+
+
+def names_are_unique(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """
+    Check that the names of the :paramref:`items` are unique.
+
+    The :paramref:`items` are a generic sequence, so the sequences of
+    the descendants of :py:class:`.types.Item` can be passed without a copy.
+    """
+    # pylint: disable=all
+    name_set: Set[str] = set()
+    for item in items:
+        if item.name in name_set:
+            return False
+        name_set.add(item.name)
+    return True
+
+
+def names_are_non_empty(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """Iterate over a generic sequence in a generator."""
+    # pylint: disable=all
+    return (
+        all(
+            len(item.name) > 0
+            for item in items
+        ))
+
+
+def some_special_item_has_level(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """Narrow the items of a generic sequence in a generator."""
+    # pylint: disable=all
+    return (
+        any(
+            (
+                isinstance(item, our_types.SpecialItem)
+                and item.level > 0
+            )
+            for item in items
+        ))
+
+
+def first_is_special(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """Index a generic sequence, and narrow the item."""
+    # pylint: disable=all
+    if len(items) == 0:
+        return False
+    first = items[0]
+    if isinstance(first, our_types.SpecialItem):
+        return first.level > 0
+    return False
+
+
+def nicknames_are_unique(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """
+    Check that the nicknames of the :paramref:`items` are unique, if specified.
+
+    This mirrors the body of ``ID_shorts_are_unique`` in aas-core-meta V3.2:
+    a local variable takes an optional property of an item of a generic sequence,
+    and the loop continues if it is None.
+    """
+    # pylint: disable=all
+    nickname_set: Set[str] = set()
+    for item in items:
+        nickname = item.nickname
+        if nickname is None:
+            continue
+        if nickname in nickname_set:
+            return False
+        nickname_set.add(nickname)
+    return True
+
+
+def levels_of_special_items_are_positive(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """
+    Narrow the loop variable over a generic sequence in a for-loop.
+
+    The loop variable is of the type parameter in Go, so the down-cast needs to
+    go through ``any(...)``, and of the template parameter in C++.
+    """
+    # pylint: disable=all
+    for item in items:
+        if isinstance(item, our_types.SpecialItem):
+            if item.level <= 0:
+                return False
+    return True
+
+
+def last_is_special(
+    items: Sequence[our_types.Item]
+) -> bool:
+    """
+    Narrow an immutable local variable which holds an item of a generic sequence.
+
+    In contrast to :py:func:`first_is_special`, the local variable is annotated, so
+    it is of the parent class instead of the type parameter. Hence, Go down-casts
+    it without ``any(...)``, and C++ binds the item to a constant reference to
+    the shared pointer of the parent class.
+    """
+    # pylint: disable=all
+    if len(items) == 0:
+        return False
+    last: Final[our_types.Item] = items[len(items) - 1]
+    if isinstance(last, our_types.SpecialItem):
+        return last.level > 0
+    return False
+
+
+def names_are_disjoint(
+    items: Sequence[our_types.Item],
+    other_items: Sequence[our_types.SomeItem],
+    shared_name: str
+) -> bool:
+    """
+    Mix two generic sequences with an argument which is not generic.
+
+    The names must differ, except for the :paramref:`shared_name`, which may repeat.
+
+    Go declares two type parameters, and C++ two template parameters. The nested
+    generators iterate over two different generic sequences, so their variables
+    are of two different type parameters.
+    """
+    # pylint: disable=all
+    return (
+        all(
+            all(
+                (
+                    item.name != other_item.name
+                    or item.name == shared_name
+                )
+                for other_item in other_items
+            )
+            for item in items
+        ))
+
+
+def aliased_names_are_unique(
+    items: Sequence[our_types.Item],
+    optional_items: Optional[Sequence[our_types.Item]]
+) -> bool:
+    """
+    Use the immutable aliases of the generic sequences.
+
+    An immutable alias of the very same type shares the type annotation of
+    the aliased generic sequence, so it is a generic sequence itself. Go declares
+    the alias with the type parameter, C++ with the template parameter, while C#
+    and Java infer its type with ``var``. The ``alias_of_alias`` aliases an alias,
+    and the ``optional_alias`` aliases an optional generic sequence.
+    """
+    # pylint: disable=all
+    alias: Final[Sequence[our_types.Item]] = items
+    alias_of_alias: Final[Sequence[our_types.Item]] = alias
+    optional_alias: Final[Optional[Sequence[our_types.Item]]] = optional_items
+    for item in alias:
+        if isinstance(item, our_types.SpecialItem):
+            if item.level <= 0:
+                return False
+    return (
+        (
+            (
+            all(
+                len(item.name) > 0
+                for item in alias_of_alias
+            )
+        )
+            and names_are_unique(alias_of_alias)
+            and optional_names_are_unique(optional_alias)
+            and (
+                (
+                    (optional_alias is None)
+                    or names_are_unique(optional_alias)
+                )
+            )
+        ))
+
+
+def contains_some_item(
+    some_item: our_types.SomeItem,
+    items: Sequence[our_types.Item]
+) -> bool:
+    """
+    Look up an instance of a descendant in a generic sequence.
+
+    Go compares the instances as ``any``'s, as the items are of the type parameter,
+    and C++ converts the member to the shared pointer of :py:class:`.types.Item` so that
+    the raw pointers are comparable for any template parameter.
+    """
+    # pylint: disable=all
+    return some_item in items
+
+
+def items_overlap(
+    items: Sequence[our_types.Item],
+    other_items: Sequence[our_types.SomeItem]
+) -> bool:
+    """
+    Look up the items of a generic sequence in another generic sequence.
+
+    The member and the items are of two different type parameters.
+    """
+    # pylint: disable=all
+    return (
+        any(
+            other_item in items
+            for other_item in other_items
+        ))
+
+
+def contains_special_item(
+    special_item: our_types.SpecialItem,
+    items: Sequence[our_types.SpecialItem]
+) -> bool:
+    """
+    Look up an instance in a sequence which is not generic.
+
+    The :py:class:`.types.SpecialItem` has no descendants, so the :paramref:`items` are not
+    a generic sequence, but Go still compares the instances as ``any``'s.
+    """
+    # pylint: disable=all
+    return special_item in items
+
+
+def container_names_are_unique(
+    container: our_types.Container
+) -> bool:
+    """
+    Pass the local variables on to generic sequences.
+
+    The ``some_items`` is a read-only alias without an annotation, while
+    the ``all_some_items`` is an immutable local variable declared with
+    ``Final[...]``. Both hold the sequences of :py:class:`.types.SomeItem`, and are passed
+    on to the generic sequences of :py:class:`.types.Item`, required as well as optional.
+    """
+    # pylint: disable=all
+    some_items = container.some_items
+    all_some_items: Final[Sequence[our_types.SomeItem]] = container.some_items
+    return (
+        (
+            names_are_unique(some_items)
+            and names_are_unique(all_some_items)
+            and optional_names_are_unique(all_some_items)
+        ))
+
+
+def optional_names_are_unique(
+    items: Optional[Sequence[our_types.Item]]
+) -> bool:
+    """Pass an optional generic sequence on to a generic sequence."""
+    # pylint: disable=all
+    return (
+        (
+            (items is None)
+            or names_are_unique(items)
+        ))
+
+
+def some_names_are_unique(
+    some_items: Sequence[our_types.SomeItem],
+    special_items: Optional[Sequence[our_types.SpecialItem]]
+) -> bool:
+    """
+    Pass the generic sequences of the descendants on.
+
+    The :paramref:`some_items` are passed on as a required and as an optional
+    sequence of the parent class, while the :paramref:`special_items` are passed on
+    as an optional sequence and, once narrowed, as a required sequence of the parent
+    class of the parent class.
+    """
+    # pylint: disable=all
+    return (
+        (
+            names_are_unique(some_items)
+            and optional_names_are_unique(some_items)
+            and optional_names_are_unique(special_items)
+            and optional_names_are_unique(None)
+            and (
+                (
+                    (special_items is None)
+                    or names_are_unique(special_items)
+                )
+            )
+        ))
+
+
+def levels_are_positive(
+    items: Sequence[our_types.SpecialItem]
+) -> bool:
+    """
+    Check that the levels are positive.
+
+    The :py:class:`.types.SpecialItem` has no descendants, so the :paramref:`items` are not
+    a generic sequence.
+    """
+    # pylint: disable=all
+    return (
+        all(
+            item.level > 0
+            for item in items
+        ))
+
+
+class _Transformer(
+        our_types.AbstractTransformer[
+            Iterator[Error]
+        ]
+):
+    # noinspection PyMethodMayBeStatic
+    def transform_some_item(
+            self,
+            that: our_types.SomeItem
+    ) -> Iterator[Error]:
+        # No verification has been defined for SomeItem.
+        return
+        # For this uncommon return-yield construction, see:
+        # https://stackoverflow.com/questions/13243766/how-to-define-an-empty-generator-function
+        # noinspection PyUnreachableCode
+        yield
+
+    # noinspection PyMethodMayBeStatic
+    def transform_special_item(
+            self,
+            that: our_types.SpecialItem
+    ) -> Iterator[Error]:
+        # No verification has been defined for SpecialItem.
+        return
+        # For this uncommon return-yield construction, see:
+        # https://stackoverflow.com/questions/13243766/how-to-define-an-empty-generator-function
+        # noinspection PyUnreachableCode
+        yield
+
+    # noinspection PyMethodMayBeStatic
+    def transform_container(
+            self,
+            that: our_types.Container
+    ) -> Iterator[Error]:
+        if not (
+            not (that.special_items is not None)
+            or (
+                all(
+                    contains_special_item(
+                        special_item,
+                        that.special_items
+                    )
+                    for special_item in that.special_items
+                )
+            )
+        ):
+            yield Error(
+                'Each special item must be among the special items.'
+            )
+
+        if not (
+            (
+                len(that.some_items) == 0
+                or items_overlap(that.items, that.some_items)
+            )
+        ):
+            yield Error(
+                'If there are some items, they must overlap with the items.'
+            )
+
+        if not (
+            all(
+                contains_some_item(some_item, that.items)
+                for some_item in that.some_items
+            )
+        ):
+            yield Error(
+                'Some items must be among the items.'
+            )
+
+        if not (
+            aliased_names_are_unique(
+                that.some_items,
+                that.special_items
+            )
+        ):
+            yield Error(
+                'Names of some items and of special items must be unique ' +
+                'through aliases.'
+            )
+
+        if not (
+            names_are_disjoint(that.items, that.some_items, 'x')
+        ):
+            yield Error(
+                'Names of the items and of some items must be disjoint.'
+            )
+
+        if not (
+            not some_special_item_has_level(that.items)
+            or last_is_special(that.items)
+        ):
+            yield Error(
+                'If there is a special item with level, the last item must ' +
+                'be special.'
+            )
+
+        if not levels_of_special_items_are_positive(that.items):
+            yield Error(
+                'Levels of the special items among the items must be ' +
+                'positive.'
+            )
+
+        if not nicknames_are_unique(that.some_items):
+            yield Error(
+                'Nicknames of some items must be unique.'
+            )
+
+        if not (that.count_items(that.items) == len(that.items)):
+            yield Error(
+                'Count of the items must match the number of the items.'
+            )
+
+        if not optional_names_are_unique(that.special_items):
+            yield Error(
+                'Names of the special items must be unique.'
+            )
+
+        if not (
+            not (that.special_items is not None)
+            or first_is_special(that.special_items)
+        ):
+            yield Error(
+                'The first special item must be special.'
+            )
+
+        if not (
+            not (that.special_items is not None)
+            or levels_are_positive(that.special_items)
+        ):
+            yield Error(
+                'Levels of the special items must be positive.'
+            )
+
+        if not (
+            not some_special_item_has_level(that.items)
+            or first_is_special(that.items)
+        ):
+            yield Error(
+                'If there is a special item with level, the first item must ' +
+                'be special.'
+            )
+
+        if not names_are_non_empty(that.some_items):
+            yield Error(
+                'Names of some items must be non-empty.'
+            )
+
+        if not (
+            some_names_are_unique(
+                that.some_items,
+                that.special_items
+            )
+        ):
+            yield Error(
+                'Names of some items and of special items must be unique.'
+            )
+
+        if not names_are_unique(that.items):
+            yield Error(
+                'Names of the items must be unique.'
+            )
+
+        for error in _verify_list_of__class(that.items):
+            error.path._prepend(
+                PropertySegment(
+                    that,
+                    'items'
+                )
+            )
+            yield error
+
+        for error in _verify_list_of__class(that.some_items):
+            error.path._prepend(
+                PropertySegment(
+                    that,
+                    'some_items'
+                )
+            )
+            yield error
+
+        if that.special_items is not None:
+            for error in _verify_list_of__class(that.special_items):
+                error.path._prepend(
+                    PropertySegment(
+                        that,
+                        'special_items'
+                    )
+                )
+                yield error
+
+    # noinspection PyMethodMayBeStatic
+    def transform_wrapper(
+            self,
+            that: our_types.Wrapper
+    ) -> Iterator[Error]:
+        if not container_names_are_unique(that.container):
+            yield Error(
+                'Names of some items of the container must be unique.'
+            )
+
+        for error in verify(that.container):
+            error.path._prepend(
+                PropertySegment(
+                    that,
+                    'container'
+                )
+            )
+            yield error
+
+
+_TRANSFORMER = _Transformer()
+
+
+def verify(
+        that: our_types.Class
+) -> Iterator[Error]:
+    """
+    Verify the constraints of :paramref:`that` recursively.
+
+    :param that: instance whose constraints we want to verify
+    :yield: constraint violations
+    """
+    yield from _TRANSFORMER.transform(that)
+
+
+def _verify_list_of__class(
+        that: Sequence[our_types.Class]
+) -> Iterator[Error]:
+    """Verify the items of :paramref:`that` recursively."""
+    for i, item in enumerate(that):
+        for error in verify(item):
+            error.path._prepend(
+                IndexSegment(
+                    that,
+                    i
+                )
+            )
+            yield error
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlcommon.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlcommon.py
new file mode 100644
index 000000000..a1d73d712
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlcommon.py
@@ -0,0 +1,759 @@
+"""
+Provide the primitives which the modules reading and writing XML share.
+
+Reading means walking a stream of ``(event, element)`` tuples: checking that
+an element resides in the expected namespace, consuming the end element which
+corresponds to a start element and taking the text out of an element. Writing
+means framing an element. Each of these is defined here exactly once, so that
+neither :py:mod:`dummy.xmlization` nor the XML-RPC subset
+over which a JSON-able value is de/serialized carries a copy of its own.
+
+The namespace is a constant of this module, :py:attr:`NAMESPACE`, and no
+argument of its primitives. This module is generated for a single meta-model,
+and a meta-model prescribes exactly one namespace, so there is nothing for
+a caller to choose.
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import json
+import re
+import sys
+from typing import (
+    Callable,
+    Iterator,
+    List,
+    Mapping,
+    Optional,
+    Sequence,
+    TextIO,
+    Tuple,
+    Union
+)
+
+if sys.version_info >= (3, 8):
+    from typing import (
+        Final,
+        Protocol
+    )
+else:
+    from typing_extensions import (
+        Final,
+        Protocol
+    )
+
+
+#: XML namespace in which all the elements of a document are expected to reside
+NAMESPACE = 'https://dummy.com'
+
+
+class Element(Protocol):
+    """Behave like :py:meth:`xml.etree.ElementTree.Element`."""
+
+    @property
+    def attrib(self) -> Optional[Mapping[str, str]]:
+        """Attributes of the element"""
+        raise NotImplementedError()
+
+    @property
+    def text(self) -> Optional[str]:
+        """Text content of the element"""
+        raise NotImplementedError()
+
+    @property
+    def tail(self) -> Optional[str]:
+        """Tail text of the element"""
+        raise NotImplementedError()
+
+    @property
+    def tag(self) -> str:
+        """Tag of the element; with a namespace provided as a ``{...}`` prefix"""
+        raise NotImplementedError()
+
+    def clear(self) -> None:
+        """Behave like :py:meth:`xml.etree.ElementTree.Element.clear`."""
+        raise NotImplementedError()
+
+
+class HasIterparse(Protocol):
+    """Parse an XML document incrementally."""
+
+    # NOTE (mristin):
+    # ``self`` is not used in this context, but is necessary for Mypy,
+    # see: https://github.com/python/mypy/issues/5018 and
+    # https://github.com/python/mypy/commit/3efbc5c5e910296a60ed5b9e0e7eb11dd912c3ed#diff-e165eb7aed9dca0a5ebd93985c8cd263a6462d36ac185f9461348dc5a1396d76R9937
+
+    def iterparse(
+            self,
+            source: TextIO,
+            events: Optional[Sequence[str]] = None
+    ) -> Iterator[Tuple[str, Element]]:
+        """Behave like :py:func:`xml.etree.ElementTree.iterparse`."""
+
+
+# NOTE (mristin):
+# The SDK defines three of these path vocabularies: this one, the one in
+# :py:mod:`dummy.jsonization`, and the one in
+# :py:mod:`dummy.xmlcommon`.
+# They look alike, and it is tempting to merge them, but they are not
+# interchangeable.
+#
+# Each of them points into a different thing, and every segment carries
+# a back-pointer to the container it stepped through, so the type of that
+# back-pointer differs from one to the next:
+#
+# * This one points into the instances which you built, so a property
+#   segment holds a class of the meta-model.
+# * The jsonization's points into the JSON-able structure being read or
+#   written, so a property segment holds the JSON-able mapping instead:
+#   while a document is being parsed, the instance which the property would
+#   belong to does not exist yet.
+# * The xmlcommon's points into the XML document, where there are no
+#   properties at all, only elements, so it names an element instead.
+#
+# The three also render differently: a path into the instances is a Python
+# access expression, a path into a JSON-able structure starts at the root of
+# the document and carries no leading dot, and a path into an XML document
+# is a relative XPath.
+#
+# Merging them would mean either dropping the back-pointers, which have been
+# part of the public API of this SDK since before these modules were split
+# apart, or defining a single path over the union of all the segment kinds --
+# in which case every consumer would have to handle segments which can never
+# occur in its world. Three small vocabularies which each say exactly what
+# they can say cost less than one large one which lies about its range.
+
+
+class ElementSegment:
+    """Represent an element on a path to the erroneous value."""
+    #: Erroneous element
+    element: Final[Element]
+
+    def __init__(
+            self,
+            element: Element
+    ) -> None:
+        """Initialize with the given values."""
+        self.element = element
+
+    def __str__(self) -> str:
+        """
+        Render the segment as a tag without the namespace.
+
+        We deliberately omit the namespace in the tag names. If you want to actually
+        query with the resulting XPath, you have to insert the namespaces manually.
+        We did not know how to include the namespace in a meaningful way, as XPath
+        assumes namespace prefixes to be defined *outside* of the document. At least
+        the path thus rendered is informative, and you should be able to descend it
+        manually.
+        """
+        _, has_namespace, tag_wo_ns = self.element.tag.rpartition('}')
+        if not has_namespace:
+            return self.element.tag
+        else:
+            return tag_wo_ns
+
+
+class IndexSegment:
+    """Represent an element in a sequence on a path to the erroneous value."""
+    #: Erroneous element
+    element: Final[Element]
+
+    #: Index of the element in the sequence, starting at zero
+    index: Final[int]
+
+    def __init__(
+            self,
+            element: Element,
+            index: int
+    ) -> None:
+        """Initialize with the given values."""
+        self.element = element
+        self.index = index
+
+    def __str__(self) -> str:
+        """
+        Render the segment as an element wildcard with the index.
+
+        XPath counts the elements starting at one, so we add one to :py:attr:`index`.
+        """
+        return f'*[{self.index + 1}]'
+
+
+class KeySegment:
+    """
+    Represent a member of an open JSON-able object on a path to
+    the erroneous element.
+
+    Unlike an :py:class:`ElementSegment`, which names an element prescribed by
+    the meta-model, a key is known only at run time, and can be any string
+    at all.
+    """
+    #: Element of the ``<member>`` which carries the key
+    element: Final[Element]
+
+    #: Key of the member
+    key: Final[str]
+
+    def __init__(
+            self,
+            element: Element,
+            key: str
+    ) -> None:
+        """Initialize with the given values."""
+        self.element = element
+        self.key = key
+
+    def __str__(self) -> str:
+        """
+        Render the segment as a predicate on the ``<name>`` child element.
+
+        A JSON-able object is written as an XML-RPC ``<struct>``, which carries
+        the key of a member in a ``<name>`` child element instead of in
+        an attribute, so the XPath has to match on that child element.
+        """
+        escaped = (
+            self.key
+            .replace('&', '&amp;')
+            .replace('/', '&#47;')
+            .replace('<', '&lt;')
+            .replace('>', '&gt;')
+            .replace('"', '&quot;')
+            .replace("'", '&apos;')
+        )
+        return f'member[name="{escaped}"]'
+
+
+Segment = Union[ElementSegment, IndexSegment, KeySegment]
+
+
+class Path:
+    """Represent the relative path to the erroneous element."""
+
+    def __init__(self) -> None:
+        """Initialize as an empty path."""
+        self._segments = []  # type: List[Segment]
+
+    @property
+    def segments(self) -> Sequence[Segment]:
+        """Get the segments of the path."""
+        return self._segments
+
+    def _prepend(self, segment: Segment) -> None:
+        """Insert the :paramref:`segment` in front of other segments."""
+        self._segments.insert(0, segment)
+
+    def __str__(self) -> str:
+        """Render the path as a relative XPath.
+
+        We omit the leading ``/`` so that you can easily prefix it as you need.
+        """
+        return "/".join(str(segment) for segment in self._segments)
+
+
+class DeserializationException(Exception):
+    """Signal that the XML de-serialization could not be performed."""
+
+    #: Human-readable explanation of the exception's cause
+    cause: Final[str]
+
+    #: Relative path to the erroneous value
+    path: Final[Path]
+
+    def __init__(
+            self,
+            cause: str
+    ) -> None:
+        """Initialize with the given :paramref:`cause` and an empty path."""
+        self.cause = cause
+        self.path = Path()
+
+
+class SerializationException(Exception):
+    """Signal that the XML serialization could not be performed."""
+
+    #: Human-readable explanation of the exception's cause
+    cause: Final[str]
+
+    def __init__(
+            self,
+            cause: str
+    ) -> None:
+        """Initialize with the given :paramref:`cause` and an empty path."""
+        self.cause = cause
+        self._segments = []  # type: List[str]
+
+    @property
+    def path(self) -> str:
+        """
+        Render the path to the erroneous value as a Python access expression.
+
+        The path points into the instance which you handed over for
+        the serialization, and *not* into an XML document -- at the point of
+        the failure, there is no document yet. For example, ``.submodels[0].id``
+        tells you that the serialization broke on ``that.submodels[0].id``.
+
+        Mind that the elements which the XML representation adds on top of
+        the instance contribute no segment, as they correspond to no attribute
+        access. This concerns the element enclosing the instance itself, and
+        the element which designates the model type of the value of a property.
+        """
+        return ''.join(self._segments)
+
+    def _prepend_property(self, name: str) -> None:
+        """Insert the access to the property :paramref:`name` before the path."""
+        self._segments.insert(0, f'.{name}')
+
+    def _prepend_index(self, index: int) -> None:
+        """Insert the access to the item at :paramref:`index` before the path."""
+        self._segments.insert(0, f'[{index}]')
+
+    def _prepend_key(self, key: str) -> None:
+        """
+        Insert the access to the member :paramref:`key` before the path.
+
+        Unlike a property of one of our classes, a member of an open JSON-able
+        object is known only at run time and can be any string at all, so it is
+        always rendered as a subscript.
+        """
+        self._segments.insert(0, f'[{json.dumps(key, ensure_ascii=False)}]')
+
+    def __str__(self) -> str:
+        if len(self._segments) == 0:
+            return self.cause
+
+        return f'{self.path}: {self.cause}'
+
+
+# region De-serialization
+
+
+def parse_element_tag(
+        element: Element
+) -> str:
+    """
+    Extract the tag name without the namespace prefix from :paramref:`element`.
+
+    :param element: whose tag without namespace we want to extract
+    :return: tag name without the namespace prefix
+    :raise: :py:class:`DeserializationException` if unexpected :paramref:`element`
+    """
+    # NOTE (mristin):
+    # :py:mod:`xml.etree.ElementTree` spells the tag of a namespaced element
+    # as ``{namespace}tag``. We match that prefix in place, with
+    # :py:meth:`str.startswith` and an offset, instead of composing
+    # the ``{...}`` form: this runs for every element of every document, and
+    # composing it would allocate a string on each call.
+    if (
+        element.tag.startswith('{')
+        and element.tag.startswith(NAMESPACE, 1)
+        and element.tag.startswith('}', len(NAMESPACE) + 1)
+    ):
+        return element.tag[len(NAMESPACE) + 2:]
+
+    got_namespace, separator, tag_wo_ns = (
+        element.tag.rpartition('}')
+    )
+
+    if separator:
+        if got_namespace.startswith('{'):
+            got_namespace = got_namespace[1:]
+
+        raise DeserializationException(
+            f"Expected the element in the namespace {NAMESPACE!r}, "
+            f"but got the element {tag_wo_ns!r} in "
+            f"the namespace {got_namespace!r}"
+        )
+
+    raise DeserializationException(
+        f"Expected the element in the namespace {NAMESPACE!r}, "
+        f"but got the element {tag_wo_ns!r} without the namespace prefix"
+    )
+
+
+def raise_if_non_whitespace_text(
+        element: Element,
+        expected_what: str
+) -> None:
+    """
+    Check that :paramref:`element` encloses no text of its own.
+
+    An element which holds other elements may still be spelled over several
+    lines, so the whitespace between its children is text as far as
+    :py:mod:`xml.etree.ElementTree` is concerned. Anything else is not.
+
+    :param element: to be verified
+    :param expected_what: what the element was expected to enclose
+    :raise:
+        :py:class:`.DeserializationException` if there is text;
+        conforming to the convention about handling error paths,
+        the exception path is left empty.
+    """
+    if element.text is not None and len(element.text.strip()) != 0:
+        raise DeserializationException(
+            f"Expected only {expected_what} and whitespace text, "
+            f"but got text: {element.text!r}"
+        )
+
+
+def read_next_start_element(
+        iterator: Iterator[Tuple[str, Element]],
+        expected_what: str
+) -> Element:
+    """
+    Read the next start element from :paramref:`iterator`.
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param expected_what: what we expected to read, for the error messages
+    :raise:
+        :py:class:`.DeserializationException` if the input ended, or if what came
+        next was no start element; conforming to the convention about handling
+        error paths, the exception path is left empty.
+    :return: the start element
+    """
+    next_event_element = next(iterator, None)
+    if next_event_element is None:
+        raise DeserializationException(
+            f"Expected the start element for {expected_what}, "
+            f"but got the end-of-input"
+        )
+
+    next_event, next_element = next_event_element
+    if next_event != 'start':
+        raise DeserializationException(
+            f"Expected the start element for {expected_what}, "
+            f"but got event {next_event!r} and element {next_element.tag!r}"
+        )
+
+    return next_element
+
+
+def raise_if_has_tail_or_attrib(
+        element: Element
+) -> None:
+    """
+    Check that :paramref:`element` has no trailing text and no attributes.
+
+    :param element: to be verified
+    :raise:
+        :py:class:`.DeserializationException` if trailing text or attributes;
+        conforming to the convention about handling error paths,
+        the exception path is left empty.
+    """
+    if element.tail is not None and len(element.tail.strip()) != 0:
+        raise DeserializationException(
+            f"Expected no trailing text, but got: {element.tail!r}"
+        )
+
+    if element.attrib is not None and len(element.attrib) > 0:
+        raise DeserializationException(
+            f"Expected no attributes, but got: {element.attrib}"
+        )
+
+
+def read_end_element(
+        element: Element,
+        iterator: Iterator[Tuple[str, Element]]
+) -> Element:
+    """
+    Read the end element corresponding to the start :paramref:`element`
+    from :paramref:`iterator`.
+
+    :param element: corresponding start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    """
+    next_event_element = next(iterator, None)
+    if next_event_element is None:
+        raise DeserializationException(
+            f"Expected the end element for {element.tag}, "
+            f"but got the end-of-input"
+        )
+
+    next_event, next_element = next_event_element
+    if next_event != "end" or next_element.tag != element.tag:
+        raise DeserializationException(
+            f"Expected the end element for {element.tag!r}, "
+            f"but got the event {next_event!r} and element {next_element.tag!r}"
+        )
+
+    raise_if_has_tail_or_attrib(next_element)
+
+    return next_element
+
+
+def read_text_from_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> str:
+    """
+    Extract the text from the :paramref:`element`, and read
+    the end element from :paramref:`iterator`.
+
+    The :paramref:`element` is expected to contain text. Otherwise,
+    it is considered as unexpected input.
+
+    :param element: start element enclosing the text
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    """
+    raise_if_has_tail_or_attrib(element)
+
+    text = element.text
+
+    end_element = read_end_element(
+        element,
+        iterator,
+    )
+
+    if text is None:
+        if end_element.text is None:
+            raise DeserializationException(
+                "Expected an element with text, but got an element with no text."
+            )
+
+        text = end_element.text
+
+    return text
+
+
+def read_str_from_element_text(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> str:
+    """
+    Parse the text of :paramref:`element` as a string, and
+    read the corresponding end element from :paramref:`iterator`.
+
+    If there is no text, empty string is returned.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed value
+    """
+    # NOTE (mristin):
+    # We do not use ``read_text_from_element`` as that function expects
+    # the ``element`` to contain *some* text. In contrast, this function
+    # can also deal with empty text, in which case it returns an empty string.
+
+    text = element.text
+
+    end_element = read_end_element(
+        element,
+        iterator
+    )
+
+    if text is None:
+        text = end_element.text
+
+    raise_if_has_tail_or_attrib(element)
+    result = (
+        text
+        if text is not None
+        else ""
+    )
+
+    return result
+
+
+#: Match a run of the whitespace characters which XSD knows
+XS_WHITESPACE_RE = re.compile(r"[ \t\n\r]+")
+
+
+def collapse_whitespace(text: str) -> str:
+    """
+    Normalize :paramref:`text` the way ``whiteSpace="collapse"`` prescribes.
+
+    Every atomic XSD type except a string, and every type derived from one
+    by restriction, fixes ``whiteSpace`` to ``collapse``, and a schema author
+    can not change it. A tab, a line feed and a carriage return each become
+    a space, a run of spaces becomes one space, and the leading and trailing
+    spaces go. Only then is the result a lexical representation to be matched.
+
+    Mind that this strips only the whitespace *around* the value: a space
+    within it survives as a single space, so ``2  3`` becomes ``2 3``, which
+    is still no number.
+
+    See: https://www.w3.org/TR/xmlschema-2/#rf-whiteSpace
+
+    :param text: to be normalized
+    :return: normalized text
+    """
+    return XS_WHITESPACE_RE.sub(" ", text).strip(" ")
+
+
+# endregion
+
+
+# region Serialization
+
+
+class Writer:
+    """
+    Write the XML elements of a single document to :py:attr:`~stream`.
+
+    The namespace is specified on the very first element alone, and on none of
+    the elements which follow it, so one writer serves exactly one document.
+    """
+
+    #: Stream to be written to
+    stream: Final[TextIO]
+
+    #: Method pointer to be invoked for writing the start element with or without
+    #: specifying a namespace (depending on the state of the writer)
+    write_start_element: Callable[
+        [str],
+        None
+    ]
+
+    #: Method pointer to be invoked for writing an empty element with or without
+    #: specifying a namespace (depending on the state of the writer)
+    write_empty_element: Callable[
+        [str],
+        None
+    ]
+
+    # NOTE (mristin):
+    # The serialization procedure is quite rigid. We leverage the specifics of
+    # the serialization procedure to optimize the code a bit.
+    #
+    # Namely, we model the writing of the XML elements as a state machine.
+    # The namespace is only specified for the very first element. All the subsequent
+    # elements will *not* have the namespace specified. We implement that behavior by
+    # using pointers to methods, as Python treats the methods as first-class citizens.
+    #
+    # The ``write_start_element`` will point to
+    # ``_write_first_start_element_with_namespace`` on the *first* invocation.
+    # Afterwards, it will be redirected to ``_write_start_element_without_namespace``.
+    #
+    # Analogously for ``write_empty_element``.
+    #
+    # Please see the implementation for the details, but this should give you at least
+    # a rough overview.
+
+    def _write_first_start_element_with_namespace(
+            self,
+            name: str
+    ) -> None:
+        """
+        Write the start element with the tag name :paramref:`name` and specify
+        its namespace.
+
+        The :py:attr:`~write_start_element` is set to
+        :py:meth:`~_write_start_element_without_namespace` after the first invocation
+        of this method.
+
+        :param name: of the element tag. Expected to contain no XML special characters.
+        """
+        self.stream.write(f'<{name} xmlns="{NAMESPACE}">')
+
+        # NOTE (mristin):
+        # Any subsequence call to `write_start_element` or `write_empty_element`
+        # should not specify the namespace of the element as we specified now already
+        # specified it.
+        self.write_start_element = self._write_start_element_without_namespace
+        self.write_empty_element = self._write_empty_element_without_namespace
+
+    def _write_start_element_without_namespace(
+            self,
+            name: str
+    ) -> None:
+        """
+        Write the start element with the tag name :paramref:`name`.
+
+        The first element, written *before* this one, is expected to have been
+        already written with the namespace specified.
+
+        :param name: of the element tag. Expected to contain no XML special characters.
+        """
+        self.stream.write(f'<{name}>')
+
+    def write_end_element(
+            self,
+            name: str
+    ) -> None:
+        """
+        Write the end element with the tag name :paramref:`name`.
+
+        :param name: of the element tag. Expected to contain no XML special characters.
+        """
+        self.stream.write(f'</{name}>')
+
+    def _write_first_empty_element_with_namespace(
+            self,
+            name: str
+    ) -> None:
+        """
+        Write the first (and only) empty element with the tag name :paramref:`name`.
+
+        No elements are expected to be written to the stream afterwards. The element
+        includes the namespace specification.
+
+        :param name: of the element tag. Expected to contain no XML special characters.
+        """
+        self.stream.write(f'<{name} xmlns="{NAMESPACE}"/>')
+        self.write_empty_element = self._raise_if_write_element_called_again
+        self.write_start_element = self._raise_if_write_element_called_again
+
+    def _raise_if_write_element_called_again(
+            self,
+            name: str
+    ) -> None:
+        raise AssertionError(
+            f"We expected to call ``_write_first_empty_element_with_namespace`` "
+            f"only once. This is an unexpected second call for writing "
+            f"an (empty or non-empty) element with the tag name: {name!r}"
+        )
+
+    def _write_empty_element_without_namespace(
+            self,
+            name: str
+    ) -> None:
+        """
+        Write the empty element with the tag name :paramref:`name`.
+
+        The call to this method is expected to occur *after* the enclosing element with
+        a specified namespace has been written.
+
+        :param name: of the element tag. Expected to contain no XML special characters.
+        """
+        self.stream.write(f'<{name}/>')
+
+    def __init__(
+        self,
+        stream: TextIO
+    ) -> None:
+        """
+        Initialize the writer to write to :paramref:`stream`.
+
+        The first element will include the :py:attr:`NAMESPACE`. Every other
+        element will not have the namespace specified.
+
+        :param stream: where to write to
+        """
+        self.stream = stream
+        self.write_start_element = (
+            self._write_first_start_element_with_namespace
+        )
+        self.write_empty_element = (
+            self._write_first_empty_element_with_namespace
+        )
+
+
+# endregion
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlization.py b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlization.py
new file mode 100644
index 000000000..4bdbb0da7
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/dummy/xmlization.py
@@ -0,0 +1,2476 @@
+"""
+Read and write model instances as XML.
+
+For reading, we provide different reading functions, each handling a different kind
+of input. All the reading functions operate in one pass, *i.e.*, the source is read
+incrementally and the complete XML is not held in memory.
+
+We provide the following four reading functions (where ``X`` represents the name of
+the class):
+
+1) ``X_from_iterparse`` reads from a stream of ``(event, element)`` tuples coming from
+   :py:func:`xml.etree.ElementTree.iterparse` with the argument
+   ``events=["start", "end"]``. If you do not trust the source, please consider
+   using `defusedxml.ElementTree`_.
+2) ``X_from_stream`` reads from the given text stream.
+3) ``X_from_file`` reads from a file on disk.
+4) ``X_from_str`` reads from the given string.
+
+The functions ``X_from_stream``, ``X_from_file`` and ``X_from_str`` provide
+an extra parameter, ``has_iterparse``, which allows you to use a parsing library
+different from :py:mod:`xml.etree.ElementTree`. For example, you can pass in
+`defusedxml.ElementTree`_.
+
+.. _defusedxml.ElementTree: https://pypi.org/project/defusedxml/#defusedxml-elementtree
+
+All XML elements are expected to live in the :py:attr:`~NAMESPACE`.
+
+For writing, use the function :py:func:`dummy.xmlization.write` which
+translates the instance of the model into an XML document and writes it in one pass
+to the stream.
+
+The writing raises a :py:class:`SerializationException` if it can not serialize
+the instance, be it because the stream failed or because a value could not be
+written. The path of the exception points to the culprit as a Python access
+expression, *e.g.*, ``.submodels[0].id``, so that you can find it in the instance
+which you handed over.
+
+Here is an example usage how to de-serialize from a file:
+
+.. code-block::
+
+    import pathlib
+    import xml.etree.ElementTree as ET
+
+    import dummy.xmlization as our_xmlization
+
+    path = pathlib.Path(...)
+    instance = our_xmlization.read_some_item_from_file(
+        path
+    )
+
+    # Do something with the ``instance``
+
+Here is another code example where we serialize the instance:
+
+.. code-block::
+
+    import pathlib
+
+    import dummy.types as our_types
+    import dummy.xmlization as our_xmlization
+
+    instance = SomeItem(
+       ... # some constructor arguments
+    )
+
+    pth = pathlib.Path(...)
+    with pth.open("wt") as fid:
+        our_xmlization.write(instance, fid)
+"""
+
+
+# This code has been automatically generated by aas-core-codegen.
+# Do NOT edit or append.
+
+
+import base64
+import enum
+import io
+import math
+import os
+import re
+import sys
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Iterator,
+    List,
+    Mapping,
+    NoReturn,
+    Optional,
+    Sequence,
+    TextIO,
+    Tuple,
+    TypeVar,
+    TYPE_CHECKING
+)
+import xml.etree.ElementTree
+
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
+
+import dummy.stringification as our_stringification
+import dummy.types as our_types
+import dummy.xmlcommon as our_xmlcommon
+from dummy.xmlcommon import (
+    XS_WHITESPACE_RE,
+    collapse_whitespace,
+    parse_element_tag,
+    raise_if_has_tail_or_attrib,
+    read_end_element,
+    read_next_start_element,
+    read_str_from_element_text,
+    read_text_from_element
+)
+
+# See: https://stackoverflow.com/questions/55076778/why-isnt-this-function-type-annotated-correctly-error-missing-type-parameters
+if TYPE_CHECKING:
+    PathLike = os.PathLike[Any]
+else:
+    PathLike = os.PathLike
+
+
+#: XML namespace in which all the elements are expected to reside
+NAMESPACE = our_xmlcommon.NAMESPACE
+
+
+# region De-serialization
+
+
+Element = our_xmlcommon.Element
+HasIterparse = our_xmlcommon.HasIterparse
+
+ElementSegment = our_xmlcommon.ElementSegment
+IndexSegment = our_xmlcommon.IndexSegment
+KeySegment = our_xmlcommon.KeySegment
+Segment = our_xmlcommon.Segment
+Path = our_xmlcommon.Path
+
+DeserializationException = our_xmlcommon.DeserializationException
+SerializationException = our_xmlcommon.SerializationException
+
+
+def _with_elements_cleared_after_yield(
+        iterator: Iterator[Tuple[str, Element]]
+) -> Iterator[Tuple[str, Element]]:
+    """
+    Map the :paramref:`iterator` such that the element is ``clear()``'ed
+    *after* every ``yield``.
+
+    :param iterator: to be mapped
+    :yield: event and element from :paramref:`iterator`
+    """
+    for event, element in iterator:
+        yield event, element
+        element.clear()
+
+
+def item_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Item:
+    """
+    Read an instance of :py:class:`.types.Item` from
+    the :paramref:`iterator`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.item_from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Item` read from
+        :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_item_as_element,
+        'Item'
+    )
+
+
+def item_from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Item:
+    """
+    Read an instance of :py:class:`.types.Item` from
+    the :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.item_from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance of
+        :py:class:`.types.Item` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Item` read from
+        :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def item_from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Item:
+    """
+    Read an instance of :py:class:`.types.Item` from
+    the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.item_from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance of
+        :py:class:`.types.Item` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Item` read from
+        :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return item_from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def item_from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Item:
+    """
+    Read an instance of :py:class:`.types.Item` from
+    the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.item_from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance of
+        :py:class:`.types.Item` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Item` read from
+        :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def some_item_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem` from
+    the :paramref:`iterator`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.some_item_from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SomeItem` read from
+        :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_some_item_as_element,
+        'SomeItem'
+    )
+
+
+def some_item_from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem` from
+    the :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.some_item_from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance of
+        :py:class:`.types.SomeItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SomeItem` read from
+        :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return some_item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def some_item_from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem` from
+    the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.some_item_from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance of
+        :py:class:`.types.SomeItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SomeItem` read from
+        :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return some_item_from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def some_item_from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem` from
+    the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.some_item_from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance of
+        :py:class:`.types.SomeItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SomeItem` read from
+        :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return some_item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def special_item_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem` from
+    the :paramref:`iterator`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.special_item_from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SpecialItem` read from
+        :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_special_item_as_element,
+        'SpecialItem'
+    )
+
+
+def special_item_from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem` from
+    the :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.special_item_from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance of
+        :py:class:`.types.SpecialItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SpecialItem` read from
+        :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return special_item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def special_item_from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem` from
+    the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.special_item_from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance of
+        :py:class:`.types.SpecialItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SpecialItem` read from
+        :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return special_item_from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def special_item_from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem` from
+    the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.special_item_from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance of
+        :py:class:`.types.SpecialItem` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.SpecialItem` read from
+        :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return special_item_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def container_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container` from
+    the :paramref:`iterator`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.container_from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Container` read from
+        :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_container_as_element,
+        'Container'
+    )
+
+
+def container_from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container` from
+    the :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.container_from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance of
+        :py:class:`.types.Container` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Container` read from
+        :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return container_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def container_from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container` from
+    the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.container_from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance of
+        :py:class:`.types.Container` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Container` read from
+        :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return container_from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def container_from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container` from
+    the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.container_from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance of
+        :py:class:`.types.Container` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Container` read from
+        :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return container_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def wrapper_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper` from
+    the :paramref:`iterator`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.wrapper_from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Wrapper` read from
+        :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_wrapper_as_element,
+        'Wrapper'
+    )
+
+
+def wrapper_from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper` from
+    the :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.wrapper_from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance of
+        :py:class:`.types.Wrapper` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Wrapper` read from
+        :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return wrapper_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def wrapper_from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper` from
+    the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.wrapper_from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance of
+        :py:class:`.types.Wrapper` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Wrapper` read from
+        :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return wrapper_from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def wrapper_from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper` from
+    the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.wrapper_from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance of
+        :py:class:`.types.Wrapper` in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Wrapper` read from
+        :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return wrapper_from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def from_iterparse(
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Class:
+    """
+    Read an instance from the :paramref:`iterator`.
+
+    The type of the instance is determined by the very first start element.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import xml.etree.ElementTree as ET
+
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        with path.open("rt") as fid:
+            iterator = ET.iterparse(
+                source=fid,
+                events=['start', 'end']
+            )
+            instance = our_xmlization.from_iterparse(
+                iterator
+            )
+
+        # Do something with the ``instance``
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance of :py:class:`.types.Class` read from the :paramref:`iterator`
+    """
+    return _read_instance_from_iterparse(
+        iterator,
+        _read_as_element,
+        'an instance'
+    )
+
+
+def from_stream(
+    stream: TextIO,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Class:
+    """
+    Read an instance from the :paramref:`stream`.
+
+    The type of the instance is determined by the very first start element.
+
+    Example usage:
+
+    .. code-block::
+
+        import dummy.xmlization as our_xmlization
+
+        with open_some_stream_over_network(...) as stream:
+            instance = our_xmlization.from_stream(
+                stream
+            )
+
+        # Do something with the ``instance``
+
+    :param stream:
+        representing an instance in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance read from :paramref:`stream`
+    """
+    iterator = has_iterparse.iterparse(
+        stream,
+        ['start', 'end']
+    )
+    return from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+def from_file(
+    path: PathLike,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Class:
+    """
+    Read an instance from the file at the :paramref:`path`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        path = pathlib.Path(...)
+        instance = our_xmlization.from_file(
+            path
+        )
+
+        # Do something with the ``instance``
+
+    :param path:
+        to the file representing an instance in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance read from the file at :paramref:`path`
+    """
+    with open(os.fspath(path), "rt", encoding='utf-8') as fid:
+        iterator = has_iterparse.iterparse(
+            fid,
+            ['start', 'end']
+        )
+        return from_iterparse(
+            _with_elements_cleared_after_yield(iterator)
+        )
+
+
+def from_str(
+    text: str,
+    has_iterparse: HasIterparse = xml.etree.ElementTree
+) -> our_types.Class:
+    """
+    Read an instance from the :paramref:`text`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+        import dummy.xmlization as our_xmlization
+
+        text = "<...>...</...>"
+        instance = our_xmlization.from_str(
+            text
+        )
+
+        # Do something with the ``instance``
+
+    :param text:
+        representing an instance in XML
+    :param has_iterparse:
+        Module containing ``iterparse`` function.
+
+        Default is to use :py:mod:`xml.etree.ElementTree` from the standard
+        library. If you have to deal with malicious input, consider using
+        a library such as `defusedxml.ElementTree`_.
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return:
+        Instance read from :paramref:`text`
+    """
+    iterator = has_iterparse.iterparse(
+        io.StringIO(text),
+        ['start', 'end']
+    )
+    return from_iterparse(
+        _with_elements_cleared_after_yield(iterator)
+    )
+
+
+# NOTE (mristin):
+# Directly using the iterator turned out to result in very complex function
+# designs. The design became much simpler as soon as we considered one look-ahead
+# element. We came up finally with the following pattern which all the protected
+# reading functions below roughly follow:
+#
+# ..code-block::
+#
+#    _read_*(
+#       look-ahead element,
+#       iterator
+#    ) -> result
+#
+# The reading functions all read from the ``iterator`` coming from
+# :py:func:`xml.etree.ElementTree.iterparse` with the argument
+# ``events=["start", "end"]``. The exception :py:class:`.DeserializationException`
+# is raised in case of unexpected input.
+#
+# The reading functions are responsible to read the end element corresponding to the
+# start look-ahead element.
+#
+# When it comes to error reporting, we use exceptions. The exceptions are raised in
+# the *callee*, as usual. However, the context of the exception, such as the error path,
+# is added in the *caller*, as only the caller knows the context of
+# the lookahead-element. In particular, prepending the path segment corresponding to
+# the lookahead-element is the responsibility of the *caller*, and not of
+# the *callee*.
+
+
+_ValueT = TypeVar("_ValueT")
+
+#: Read the content of an element which has already been opened, and read
+#: the corresponding end element as well
+_ContentReader = Callable[
+    [Element, Iterator[Tuple[str, Element]]],
+    _ValueT
+]
+
+
+def _read_named_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]],
+    expected_tag: str,
+    read_content: _ContentReader[_ValueT]
+) -> _ValueT:
+    """
+    Verify that :paramref:`element` bears the :paramref:`expected_tag`, and
+    delegate the reading of its content to :paramref:`read_content`.
+
+    This is the only place where an element's tag is checked against the tag which
+    its container prescribes -- the XML name of a class, ``<v>`` for a list item, or
+    ``<v1>``, ``<v2>``, *etc.* for a tuple item.
+
+    :param element: look-ahead element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param expected_tag: expected tag of :paramref:`element`
+    :param read_content: to read the content of :paramref:`element`
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed value
+    """
+    tag_wo_ns = parse_element_tag(element)
+    if tag_wo_ns != expected_tag:
+        raise DeserializationException(
+            f"Expected an element with the tag {expected_tag!r}, "
+            f"but got an element with tag: {tag_wo_ns!r}"
+        )
+
+    return read_content(element, iterator)
+
+
+def _read_dispatched(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]],
+    dispatch: Mapping[str, _ContentReader[_ValueT]],
+    expected_what: str
+) -> _ValueT:
+    """
+    Read the instance of :paramref:`element` by dispatching on its own tag.
+
+    An instance element is self-describing: its tag *is* its model type.
+
+    The end element corresponding to :paramref:`element` will be read as well.
+
+    :param element: start element of the instance
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param dispatch: to read the instance as a sequence, by its model type
+    :param expected_what: what we expected to read, for the error messages
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    tag_wo_ns = parse_element_tag(element)
+
+    read_as_sequence = dispatch.get(tag_wo_ns, None)
+    if read_as_sequence is None:
+        raise DeserializationException(
+            f"Expected the element tag to be a valid model type "
+            f"of {expected_what}, "
+            f"but got tag {tag_wo_ns!r}"
+        )
+
+    return read_as_sequence(element, iterator)
+
+
+def _read_properties(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]],
+    readers: Mapping[str, _ContentReader[Any]]
+) -> Mapping[str, Any]:
+    """
+    Read the properties of an instance as the children of :paramref:`element`.
+
+    The end element corresponding to :paramref:`element` will be read as well.
+
+    A property may come at most once, and an unknown tag is refused outright.
+
+    The property is marked on the error path here, once for all the properties,
+    instead of in every reader: the tag of the child element *is* the XML name of
+    the property which we are reading.
+
+    :param element: start element, parent of the properties
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param readers: to read the content of a property, by its XML name
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed values, by the XML name of the property
+    """
+    if element.text is not None and len(element.text.strip()) != 0:
+        raise DeserializationException(
+            f"Expected only XML elements representing the properties "
+            f"and whitespace text, but got text: {element.text!r}"
+        )
+
+    raise_if_has_tail_or_attrib(element)
+
+    values = dict()  # type: Dict[str, Any]
+
+    while True:
+        # NOTE (mristin):
+        # We pull the next property element here instead of delegating it to
+        # a helper. A call is not free in Python, and this loop runs once for
+        # every property of every instance.
+        next_event_element = next(iterator, None)
+        if next_event_element is None:
+            raise DeserializationException(
+                f"Expected a property element or the end element corresponding "
+                f"to {element.tag}, but got the end-of-input"
+            )
+
+        next_event, prop_element = next_event_element
+        if next_event == 'end' and prop_element.tag == element.tag:
+            # We reached the end element enclosing the properties.
+            break
+
+        if next_event != 'start':
+            raise DeserializationException(
+                f"Expected a start element corresponding to a property, "
+                f"but got event {next_event!r} "
+                f"and element {prop_element.tag!r}"
+            )
+
+        try:
+            tag_wo_ns = parse_element_tag(prop_element)
+
+            # NOTE (mristin):
+            # A tag already in ``values`` can only have got there by being read,
+            # so its presence means that the property comes a second time.
+            if tag_wo_ns in values:
+                raise DeserializationException(
+                    f"Property {tag_wo_ns!r} occurred more than once"
+                )
+
+            reader = readers.get(tag_wo_ns, None)
+            if reader is None:
+                raise DeserializationException(
+                    f"Expected an element representing a property, "
+                    f"but got an element with unexpected tag: {tag_wo_ns!r}"
+                )
+
+            values[tag_wo_ns] = reader(prop_element, iterator)
+        except DeserializationException as exception:
+            exception.path._prepend(ElementSegment(prop_element))
+            raise
+
+    return values
+
+
+def _read_list_of_items(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]],
+    read_item: _ContentReader[_ValueT]
+) -> List[_ValueT]:
+    """
+    Read the children of :paramref:`element` as a list of items.
+
+    :paramref:`read_item` is responsible for verifying the tag of each item
+    element itself -- *e.g.*, by wrapping a scalar/enumeration reader with
+    :py:func:`_read_named_element`, or by relying on a class's own dispatch by
+    its natural element tag.
+
+    The end element corresponding to :paramref:`element` will be read as well.
+
+    :param element: start element enclosing the list
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param read_item: to read a single item, including its own end element
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed items
+    """
+    if element.text is not None and len(element.text.strip()) != 0:
+        raise DeserializationException(
+            f"Expected only item elements and whitespace text, "
+            f"but got text: {element.text!r}"
+        )
+
+    result = []  # type: List[_ValueT]
+
+    while True:
+        # NOTE (mristin):
+        # We pull the next item element here instead of delegating it to a helper,
+        # as this loop runs once for every item of every list.
+        next_event_element = next(iterator, None)
+        if next_event_element is None:
+            raise DeserializationException(
+                f"Expected an item element or the end element corresponding "
+                f"to {element.tag}, but got the end-of-input"
+            )
+
+        next_event, item_element = next_event_element
+        if next_event == 'end' and item_element.tag == element.tag:
+            # We reached the end element enclosing the items.
+            break
+
+        if next_event != 'start':
+            raise DeserializationException(
+                f"Expected a start element corresponding to an item, "
+                f"but got event {next_event!r} "
+                f"and element {item_element.tag!r}"
+            )
+
+        try:
+            item = read_item(item_element, iterator)
+        except DeserializationException as exception:
+            exception.path._prepend(IndexSegment(item_element, len(result)))
+            raise
+
+        result.append(item)
+
+    return result
+
+
+def _read_instance_from_iterparse(
+    iterator: Iterator[Tuple[str, Element]],
+    read_as_element: _ContentReader[_ValueT],
+    expected_what: str
+) -> _ValueT:
+    """
+    Read an instance from :paramref:`iterator`, starting at its start element.
+
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :param read_as_element: to read the instance, including its end element
+    :param expected_what: what we expected to read, for the error messages
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    next_element = read_next_start_element(iterator, expected_what)
+
+    try:
+        return read_as_element(next_element, iterator)
+    except DeserializationException as exception:
+        exception.path._prepend(ElementSegment(next_element))
+        raise exception
+
+
+#: Match the lexical space of ``xs:long``.
+#:
+#: Mind the explicit ``[0-9]``: ``\d`` would match a digit of any script.
+#:
+#: See: https://www.w3.org/TR/xmlschema-2/#long
+_XS_LONG_RE = re.compile(r"(\+|-)?[0-9]+")
+
+
+def _read_int_from_element_text(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> int:
+    """
+    Parse the text of :paramref:`element` as an integer, and
+    read the corresponding end element from :paramref:`iterator`.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise:
+        :py:class:`DeserializationException` if unexpected input, including
+        a value outside of the 64-bit range of ``xs:long``
+    :return: parsed value
+    """
+    text = collapse_whitespace(
+        read_text_from_element(
+            element,
+            iterator
+        )
+    )
+
+    # NOTE (mristin):
+    # ``int`` is far too permissive to be handed the text directly: it takes
+    # a digit group separator as in ``1_0``, surrounding whitespace, and
+    # a digit of any script -- the Arabic-Indic ``۵`` would be read as 5.
+    # Mind that it is checked with ``fullmatch`` and not with ``match``: ``$``
+    # would also match just before a trailing newline.
+    #
+    # See: https://www.w3.org/TR/xmlschema-2/#long
+    if _XS_LONG_RE.fullmatch(text) is None:
+        raise DeserializationException(
+            f"Expected a value as xs:long, "
+            f"but got an element with text: {text!r}"
+        )
+
+    # NOTE (mristin):
+    # We count the significant digits before we call ``int``. The conversion is
+    # quadratic in the length of the text, and Python refuses a text of more than
+    # 4300 digits, leading zeros included, although ``xs:long`` allows arbitrarily
+    # many leading zeros. The largest magnitude, 2^63, has 19 digits.
+    digits = text.lstrip("+-").lstrip("0")
+    if len(digits) > 19:
+        raise DeserializationException(
+            f"Expected a value as xs:long, "
+            f"but got an element with text out of its range: {text!r}"
+        )
+
+    value = int(digits) if len(digits) > 0 else 0
+    if text[0] == "-":
+        value = -value
+
+    # NOTE (mristin):
+    # An ``int`` is unbounded in Python, while ``xs:long`` is a 64-bit integer,
+    # so the range has to be checked explicitly, as a number of 19 digits might
+    # still not fit. Every other target gets this for free from a parser which
+    # refuses what does not fit.
+    if value < -9223372036854775808 or value > 9223372036854775807:
+        raise DeserializationException(
+            f"Expected a value as xs:long, "
+            f"but got an element with text out of its range: {text!r}"
+        )
+
+    return value
+
+
+def _read_list_of__item(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> List[our_types.Item]:
+    """
+    Read the items of :paramref:`element` as a list of
+    :py:class:`.types.Item`.
+    """
+    return _read_list_of_items(
+        element,
+        iterator,
+        _read_item_as_element
+    )
+
+
+def _read_list_of__some_item(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> List[our_types.SomeItem]:
+    """
+    Read the items of :paramref:`element` as a list of
+    :py:class:`.types.SomeItem`.
+    """
+    return _read_list_of_items(
+        element,
+        iterator,
+        _read_some_item_as_element
+    )
+
+
+def _read_list_of__special_item(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> List[our_types.SpecialItem]:
+    """
+    Read the items of :paramref:`element` as a list of
+    :py:class:`.types.SpecialItem`.
+    """
+    return _read_list_of_items(
+        element,
+        iterator,
+        _read_special_item_as_element
+    )
+
+
+def _read_item_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Item:
+    """
+    Read an instance of :py:class:`.types.Item` from
+    :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_dispatched(
+        element,
+        iterator,
+        _DISPATCH_FOR_ITEM,
+        "a concrete instance of 'Item'"
+    )
+
+
+def _read_some_item_as_sequence(
+        element: Element,
+        iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem`
+    as a sequence of XML-encoded properties.
+
+    The end element corresponding to the :paramref:`element` will be
+    read as well.
+
+    :param element: start element, parent of the sequence
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    values = _read_properties(
+        element,
+        iterator,
+        _READERS_FOR_SOME_ITEM
+    )
+
+    the_name: Optional[str] = values.get('name')
+    the_nickname: Optional[str] = values.get('nickname')
+
+    if the_name is None:
+        raise DeserializationException(
+            "The required property 'name' is missing"
+        )
+
+    return our_types.SomeItem(
+        the_name,
+        the_nickname
+    )
+
+
+def _read_some_item_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SomeItem:
+    """
+    Read an instance of :py:class:`.types.SomeItem` from
+    :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_dispatched(
+        element,
+        iterator,
+        _DISPATCH_FOR_SOME_ITEM,
+        "a concrete instance of 'SomeItem'"
+    )
+
+
+def _read_special_item_as_sequence(
+        element: Element,
+        iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem`
+    as a sequence of XML-encoded properties.
+
+    The end element corresponding to the :paramref:`element` will be
+    read as well.
+
+    :param element: start element, parent of the sequence
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    values = _read_properties(
+        element,
+        iterator,
+        _READERS_FOR_SPECIAL_ITEM
+    )
+
+    the_name: Optional[str] = values.get('name')
+    the_nickname: Optional[str] = values.get('nickname')
+    the_level: Optional[int] = values.get('level')
+
+    if the_name is None:
+        raise DeserializationException(
+            "The required property 'name' is missing"
+        )
+
+    if the_level is None:
+        raise DeserializationException(
+            "The required property 'level' is missing"
+        )
+
+    return our_types.SpecialItem(
+        the_name,
+        the_level,
+        the_nickname
+    )
+
+
+def _read_special_item_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.SpecialItem:
+    """
+    Read an instance of :py:class:`.types.SpecialItem` from
+    :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_named_element(
+        element,
+        iterator,
+        'specialItem',
+        _read_special_item_as_sequence
+    )
+
+
+def _read_container_as_sequence(
+        element: Element,
+        iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container`
+    as a sequence of XML-encoded properties.
+
+    The end element corresponding to the :paramref:`element` will be
+    read as well.
+
+    :param element: start element, parent of the sequence
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    values = _read_properties(
+        element,
+        iterator,
+        _READERS_FOR_CONTAINER
+    )
+
+    the_items: Optional[List[our_types.Item]] = values.get('items')
+    the_some_items: Optional[List[our_types.SomeItem]] = values.get('someItems')
+    the_special_items: Optional[List[our_types.SpecialItem]] = values.get('specialItems')
+
+    if the_items is None:
+        raise DeserializationException(
+            "The required property 'items' is missing"
+        )
+
+    if the_some_items is None:
+        raise DeserializationException(
+            "The required property 'someItems' is missing"
+        )
+
+    return our_types.Container(
+        the_items,
+        the_some_items,
+        the_special_items
+    )
+
+
+def _read_container_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Container:
+    """
+    Read an instance of :py:class:`.types.Container` from
+    :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_named_element(
+        element,
+        iterator,
+        'container',
+        _read_container_as_sequence
+    )
+
+
+def _read_wrapper_as_sequence(
+        element: Element,
+        iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper`
+    as a sequence of XML-encoded properties.
+
+    The end element corresponding to the :paramref:`element` will be
+    read as well.
+
+    :param element: start element, parent of the sequence
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    values = _read_properties(
+        element,
+        iterator,
+        _READERS_FOR_WRAPPER
+    )
+
+    the_container: Optional[our_types.Container] = values.get('container')
+
+    if the_container is None:
+        raise DeserializationException(
+            "The required property 'container' is missing"
+        )
+
+    return our_types.Wrapper(
+        the_container
+    )
+
+
+def _read_wrapper_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Wrapper:
+    """
+    Read an instance of :py:class:`.types.Wrapper` from
+    :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_named_element(
+        element,
+        iterator,
+        'wrapper',
+        _read_wrapper_as_sequence
+    )
+
+
+def _read_as_element(
+    element: Element,
+    iterator: Iterator[Tuple[str, Element]]
+) -> our_types.Class:
+    """
+    Read an instance from :paramref:`iterator`, including the end element.
+
+    :param element: start element
+    :param iterator:
+        Input stream of ``(event, element)`` coming from
+        :py:func:`xml.etree.ElementTree.iterparse` with the argument
+        ``events=["start", "end"]``
+    :raise: :py:class:`DeserializationException` if unexpected input
+    :return: parsed instance
+    """
+    return _read_dispatched(
+        element,
+        iterator,
+        _GENERAL_DISPATCH,
+        'a concrete instance'
+    )
+
+
+#: Dispatch XML class names to read-as-sequence functions
+#: corresponding to concrete descendants of Item
+_DISPATCH_FOR_ITEM: Mapping[
+    str,
+    Callable[
+        [
+            Element,
+            Iterator[Tuple[str, Element]]
+        ],
+        our_types.Item
+    ]
+] = {
+    'someItem': _read_some_item_as_sequence,
+    'specialItem': _read_special_item_as_sequence,
+}
+
+
+#: Dispatch XML class names to read-as-sequence functions
+#: corresponding to SomeItem and its concrete descendants
+_DISPATCH_FOR_SOME_ITEM: Mapping[
+    str,
+    Callable[
+        [
+            Element,
+            Iterator[Tuple[str, Element]]
+        ],
+        our_types.SomeItem
+    ]
+] = {
+    'someItem': _read_some_item_as_sequence,
+    'specialItem': _read_special_item_as_sequence,
+}
+
+
+#: Dispatch XML class names to read-as-sequence functions
+#: corresponding to the concrete classes
+_GENERAL_DISPATCH: Mapping[
+    str,
+    Callable[
+        [
+            Element,
+            Iterator[Tuple[str, Element]]
+        ],
+        our_types.Class
+    ]
+] = {
+    'someItem': _read_some_item_as_sequence,
+    'specialItem': _read_special_item_as_sequence,
+    'container': _read_container_as_sequence,
+    'wrapper': _read_wrapper_as_sequence,
+}
+
+
+#: Read the content of a property of
+#: :py:class:`.types.SomeItem`, by the XML name of the property
+_READERS_FOR_SOME_ITEM: Mapping[
+    str,
+    _ContentReader[Any]
+] = {
+    'name': read_str_from_element_text,
+    'nickname': read_str_from_element_text,
+}
+
+
+#: Read the content of a property of
+#: :py:class:`.types.SpecialItem`, by the XML name of the property
+_READERS_FOR_SPECIAL_ITEM: Mapping[
+    str,
+    _ContentReader[Any]
+] = {
+    'name': read_str_from_element_text,
+    'nickname': read_str_from_element_text,
+    'level': _read_int_from_element_text,
+}
+
+
+#: Read the content of a property of
+#: :py:class:`.types.Container`, by the XML name of the property
+_READERS_FOR_CONTAINER: Mapping[
+    str,
+    _ContentReader[Any]
+] = {
+    'items': _read_list_of__item,
+    'someItems': _read_list_of__some_item,
+    'specialItems': _read_list_of__special_item,
+}
+
+
+#: Read the content of a property of
+#: :py:class:`.types.Wrapper`, by the XML name of the property
+_READERS_FOR_WRAPPER: Mapping[
+    str,
+    _ContentReader[Any]
+] = {
+    'container': _read_container_as_sequence,
+}
+
+
+# endregion
+
+
+# region Serialization
+
+
+def _attribute_to_property(
+        exception: Exception,
+        prop_name: Optional[str]
+) -> NoReturn:
+    """
+    Re-raise the :paramref:`exception` as a failure of the property
+    :paramref:`prop_name`.
+
+    Every writer funnels its failures through this function, so that the path to
+    the culprit is built up as the stack unwinds: a writer knows the property whose
+    value it writes, and nothing below it does.
+
+    A :paramref:`prop_name` of ``None`` prepends nothing to the path. It does *not*
+    mean that no property is involved. It means that the access which leads to
+    the value is recorded by a writer further up the stack, so recording it here
+    as well would spell one step of the path twice.
+
+    For example, the writer of an item of a list is given no property name. The list
+    writer records its own property and the loop over the items records the index, so
+    that ``.submodel_elements[3]`` is assembled from ``submodel_elements`` above and
+    ``3`` around the item. Were the item to contribute ``submodel_elements`` as well,
+    the path would read ``.submodel_elements[3].submodel_elements``.
+
+    Likewise, an instance nested in the element of a property is written by
+    a dispatch on its run-time type, and a dispatch knows nothing about where
+    the instance came from. It is :py:func:`_write_nested_element` above it which
+    knows that the instance sits in ``.value``, so the writer which the dispatch
+    selects contributes no segment of its own.
+
+    The path therefore stays empty only when the value which broke *is* the one you
+    handed over, which is the failure :py:func:`write` funnels here: there is no
+    access leading to it to report.
+
+    We deliberately catch *any* exception, and not only the failures of
+    the underlying stream. The type annotations are not enforced at run-time, so
+    a property can hold a value which we can not serialize, and telling you where
+    that value sits is much more helpful than the bare exception. The original
+    exception is kept as the cause of the raised one.
+
+    :param exception: to be re-raised
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :raise: :py:class:`SerializationException` always
+    """
+    if isinstance(exception, SerializationException):
+        if prop_name is not None:
+            exception._prepend_property(prop_name)
+
+        raise exception
+
+    failure = SerializationException(str(exception))
+    if prop_name is not None:
+        failure._prepend_property(prop_name)
+
+    raise failure from exception
+
+
+def _attribute_to_item(
+        exception: Exception,
+        index: int
+) -> NoReturn:
+    """
+    Re-raise the :paramref:`exception` as a failure of the item at
+    :paramref:`index`.
+
+    This is the counterpart of :py:func:`_attribute_to_property` for the items of
+    a list and of a tuple. The item's own element contributes no segment to
+    the path: an item is selected by its position, and not by its element tag.
+
+    :param exception: to be re-raised
+    :param index: of the item which was being written
+    :raise: :py:class:`SerializationException` always
+    """
+    if isinstance(exception, SerializationException):
+        exception._prepend_index(index)
+        raise exception
+
+    failure = SerializationException(str(exception))
+    failure._prepend_index(index)
+    raise failure from exception
+
+
+def _write_int_as_element(
+    name: str,
+    prop_name: Optional[str],
+    value: int,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write the :paramref:`value` of an integer enclosed in
+    the :paramref:`name` element.
+
+    :param name: of the corresponding element tag
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param value: to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+        serializer.writer.stream.write(str(value))
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_str_as_element(
+    name: str,
+    prop_name: Optional[str],
+    value: str,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write the :paramref:`value` of a string enclosed in
+    the :paramref:`name` element.
+
+    :param name: of the corresponding element tag
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param value: to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+
+        # NOTE (mristin):
+        # We ran ``timeit`` on manual code which escaped XML special characters with
+        # a dictionary, and on another snippet which called three ``.replace()``.
+        # The code with ``.replace()`` was an order of magnitude faster on our
+        # computers.
+        #
+        # The escaping is written out here, and not put in a function of its own,
+        # since a string is the commonest value in a meta-model and a call is not free.
+        serializer.writer.stream.write(
+            value.replace('&', '&amp;').replace('<', '&lt;').replace('>', '&gt;')
+        )
+
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_list_of_instances(
+    name: str,
+    prop_name: Optional[str],
+    items: Sequence[our_types.Class],
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write :paramref:`items` enclosed in the :paramref:`name` element.
+
+    Every item writes the element which designates its model type, so no positional
+    tag is necessary. If there are no items, the enclosing element is collapsed to
+    an empty one.
+
+    :param name: of the enclosing element
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param items: to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        if len(items) == 0:
+            serializer.writer.write_empty_element(name)
+        else:
+            serializer.writer.write_start_element(name)
+
+            for index, item in enumerate(items):
+                try:
+                    serializer.visit(item)
+                except Exception as exception:
+                    _attribute_to_item(exception, index)
+
+            serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_some_item_as_element(
+    name: str,
+    prop_name: Optional[str],
+    that: our_types.SomeItem,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write :paramref:`that` enclosed in the :paramref:`name` element.
+
+    :param name: of the element tag. Expected to contain no XML special characters.
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param that: instance to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+        _write_str_as_element('name', 'name', that.name, serializer)
+        if that.nickname is not None:
+            _write_str_as_element('nickname', 'nickname', that.nickname, serializer)
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_special_item_as_element(
+    name: str,
+    prop_name: Optional[str],
+    that: our_types.SpecialItem,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write :paramref:`that` enclosed in the :paramref:`name` element.
+
+    :param name: of the element tag. Expected to contain no XML special characters.
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param that: instance to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+        _write_str_as_element('name', 'name', that.name, serializer)
+        if that.nickname is not None:
+            _write_str_as_element('nickname', 'nickname', that.nickname, serializer)
+        _write_int_as_element('level', 'level', that.level, serializer)
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_container_as_element(
+    name: str,
+    prop_name: Optional[str],
+    that: our_types.Container,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write :paramref:`that` enclosed in the :paramref:`name` element.
+
+    :param name: of the element tag. Expected to contain no XML special characters.
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param that: instance to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+        _write_list_of_instances('items', 'items', that.items, serializer)
+        _write_list_of_instances('someItems', 'some_items', that.some_items, serializer)
+        if that.special_items is not None:
+            _write_list_of_instances(
+                'specialItems', 'special_items', that.special_items, serializer
+            )
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+def _write_wrapper_as_element(
+    name: str,
+    prop_name: Optional[str],
+    that: our_types.Wrapper,
+    serializer: '_Serializer'
+) -> None:
+    """
+    Write :paramref:`that` enclosed in the :paramref:`name` element.
+
+    :param name: of the element tag. Expected to contain no XML special characters.
+    :param prop_name:
+        name of the property, as spelled in Python, whose value is written, or
+        ``None`` if the access to the value is recorded by an enclosing writer
+    :param that: instance to be serialized
+    :param serializer: to write to
+    :raise: :py:class:`SerializationException` if the value could not be written
+    """
+    try:
+        serializer.writer.write_start_element(name)
+        _write_container_as_element(
+            'container', 'container', that.container, serializer
+        )
+        serializer.writer.write_end_element(name)
+    except Exception as exception:
+        _attribute_to_property(exception, prop_name)
+
+
+class _Serializer(our_types.AbstractVisitor):
+    """Encode instances as XML and write them to :py:attr:`~writer`."""
+
+    #: Frame the XML elements of the document which we are writing
+    writer: Final[our_xmlcommon.Writer]
+
+    def __init__(
+        self,
+        stream: TextIO
+    ) -> None:
+        """
+        Initialize the visitor to write to :paramref:`stream`.
+
+        The first element will include the :py:attr:`~.NAMESPACE`. Every other
+        element will not have the namespace specified.
+
+        :param stream: where to write to
+        """
+        self.writer = our_xmlcommon.Writer(stream)
+
+    def visit_some_item(
+        self,
+        that: our_types.SomeItem
+    ) -> None:
+        """
+        Serialize :paramref:`that` to :py:attr:`~stream` as an XML element.
+
+        The enclosing XML element designates the class of the instance, where its
+        children correspond to the properties of the instance.
+
+        :param that: instance to be serialized
+        """
+        _write_some_item_as_element('someItem', None, that, self)
+
+    def visit_special_item(
+        self,
+        that: our_types.SpecialItem
+    ) -> None:
+        """
+        Serialize :paramref:`that` to :py:attr:`~stream` as an XML element.
+
+        The enclosing XML element designates the class of the instance, where its
+        children correspond to the properties of the instance.
+
+        :param that: instance to be serialized
+        """
+        _write_special_item_as_element('specialItem', None, that, self)
+
+    def visit_container(
+        self,
+        that: our_types.Container
+    ) -> None:
+        """
+        Serialize :paramref:`that` to :py:attr:`~stream` as an XML element.
+
+        The enclosing XML element designates the class of the instance, where its
+        children correspond to the properties of the instance.
+
+        :param that: instance to be serialized
+        """
+        _write_container_as_element('container', None, that, self)
+
+    def visit_wrapper(
+        self,
+        that: our_types.Wrapper
+    ) -> None:
+        """
+        Serialize :paramref:`that` to :py:attr:`~stream` as an XML element.
+
+        The enclosing XML element designates the class of the instance, where its
+        children correspond to the properties of the instance.
+
+        :param that: instance to be serialized
+        """
+        _write_wrapper_as_element('wrapper', None, that, self)
+
+
+def write(instance: our_types.Class, stream: TextIO) -> None:
+    """
+    Write the XML representation of :paramref:`instance` to :paramref:`stream`.
+
+    Example usage:
+
+    .. code-block::
+
+        import pathlib
+
+        import dummy.types as our_types
+        import dummy.xmlization as our_xmlization
+
+        instance = SomeItem(
+           ... # some constructor arguments
+        )
+
+        pth = pathlib.Path(...)
+        with pth.open("wt") as fid:
+            our_xmlization.write(instance, fid)
+
+    :param instance: to be serialized
+    :param stream: to write to
+    :raise:
+        :py:class:`SerializationException` if :paramref:`instance` could not be
+        serialized
+    """
+    serializer = _Serializer(stream)
+
+    try:
+        serializer.visit(instance)
+    except Exception as exception:
+        _attribute_to_property(exception, None)
+
+
+def to_str(that: our_types.Class) -> str:
+    """
+    Serialize :paramref:`that` to an XML-encoded text.
+
+    :param that: instance to be serialized
+    :raise:
+        :py:class:`SerializationException` if :paramref:`that` could not be
+        serialized
+    :return: :paramref:`that` serialized to XML serialized to text
+    """
+    writer = io.StringIO()
+    write(that, writer)
+    return writer.getvalue()
+
+
+# endregion
diff --git a/dev/test_data/main/python/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/python/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/python/expected/variance_of_containers/input/snippets/qualified_module_name.txt b/dev/test_data/main/python/expected/variance_of_containers/input/snippets/qualified_module_name.txt
new file mode 100644
index 000000000..2995a4d0e
--- /dev/null
+++ b/dev/test_data/main/python/expected/variance_of_containers/input/snippets/qualified_module_name.txt
@@ -0,0 +1 @@
+dummy
\ No newline at end of file
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/common.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/common.ts
new file mode 100644
index 000000000..4a12827cf
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/common.ts
@@ -0,0 +1,604 @@
+/**
+ * Provide common functions shared among the modules.
+ */
+
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+
+/**
+ * Create an iterator over the given range of numbers.
+ *
+ * @param start - inclusive start of the range
+ * @param end - exclusive end of the range
+ * @returns iterator over the range
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+export function *range(start: number, end: number): IterableIterator<number> {
+  for (let i = start; i < end; i++) {
+    yield i;
+  }
+}
+
+
+/**
+ * Retrieve the `index`-th item from the `array`.
+ *
+ * @remarks
+ * This is a fill for `Array.prototype.at`.
+ * See: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at
+ *
+ * @param array - to get the element from
+ * @param index - zero-based index of the `array`. Negative index counts back.
+ * @returns item, or `undefined` if `index` out-of-bound
+ * @typeParam T - type of the array items
+ */
+export function at<T>(
+  array: Array<T>,
+  index: number
+) {
+  if (index < 0) {
+    return array[array.length + index];
+  } else {
+    return array[index];
+  }
+}
+
+
+/**
+ * Set the `index`-th item of the `array` to the `value`.
+ *
+ * @remarks
+ * Unlike the plain assignment, we do not grow the array on an out-of-bound
+ * `index`, but throw so that we follow the semantics of the meta-model.
+ *
+ * @param array - to set the element in
+ * @param index - zero-based index of the `array`. Negative index counts back.
+ * @param value - to be set
+ * @throws {@link RangeError} if `index` out-of-bound
+ * @typeParam T - type of the array items
+ */
+export function setAt<T>(
+  array: Array<T>,
+  index: number,
+  value: T
+): void {
+  const resolved = index < 0 ? array.length + index : index;
+  if (resolved < 0 || resolved >= array.length) {
+    throw new RangeError(
+      `The index ${index} is out of bound ` +
+      `for the array of length ${array.length}`
+    );
+  }
+  array[resolved] = value;
+}
+
+
+/**
+ * Check that all the values of the iterable are `true`.
+ *
+ * @param iterable - to iterate over
+ * @returns `true` if all values in `iterable` are set
+ */
+export function every<T>(
+  iterable: Iterable<T>
+): boolean {
+  // NOTE (mristin):
+  // We introduce this function so that we can keep the constraint verification
+  // purely functional. Unfortunately, `every` and `some` are only available
+  // in arrays and not in `IterableIterator`.
+
+  for (const item of iterable) {
+    if (!item) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+
+/**
+ * Check that at least one value of the iterable is `true`.
+ *
+ * @param iterable - to iterate over
+ * @returns `true` if at least one value in `iterable` is set
+ */
+export function some<T>(
+  iterable: Iterable<T>
+): boolean {
+  // NOTE (mristin):
+  // We introduce this function so that we can keep the constraint verification
+  // purely functional. Unfortunately, `every` and `some` are only available
+  // in arrays and not in `IterableIterator`.
+
+  for (const item of iterable) {
+    if (item) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+
+/**
+ * Map the items of an iterable.
+ *
+ * @param iterable - to be mapped
+ * @param mappingFunction - to be applied on `iterable`
+ * @returns mapped items of `iterable`
+ * @typeParam S - type of an item of the `iterable`
+ * @typeParam T - type of the transformed item of the `iterable`
+ */
+export function *map<S, T>(
+  iterable: Iterable<S>,
+  mappingFunction: (item: S) => T
+): IterableIterator<T> {
+  // NOTE (mristin):
+  // We introduce this function so that we can keep the constraint verification
+  // purely functional.
+
+  for (const item of iterable) {
+    yield mappingFunction(item);
+  }
+}
+
+
+/**
+ * Represent either a result, or an error.
+ *
+ * @typeParam ValueT - type of the resulting value
+ * @typeParam ErrorT - type of the error
+ */
+export class Either<ValueT, ErrorT> {
+  /**
+   * value if something successful
+   */
+  readonly value: ValueT | null;
+
+  /**
+   * error if something failed
+   */
+  readonly error: ErrorT | null;
+
+  /**
+   * Assert that value is set and return it.
+   *
+   * @returns {@link value}, or throw if `null`
+   */
+  mustValue(): ValueT {
+    if (this.value === null) {
+      throw new Error("Expected value to be set, but it was null");
+    }
+    return this.value;
+  }
+
+  constructor(value: ValueT | null, error: ErrorT | null) {
+    if (value === null && error === null) {
+      throw new Error("Unexpected both value and error null in an Either");
+    }
+
+    if (value !== null && error !== null) {
+      throw new Error("Unexpected both value and error non-null in an Either");
+    }
+
+    this.value = value;
+    this.error = error;
+  }
+}
+
+
+const BASE64_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+const BASE64_LOOKUP = new Uint8Array(256);
+
+// NOTE (mristin):
+// Initialize to 255 so that we can detect invalid values in the input during decoding.
+for (let i = 0; i < BASE64_LOOKUP.length; i++) {
+  BASE64_LOOKUP[i] = 255;
+}
+
+// NOTE (mristin):
+// Initialize valid values to the corresponding decoding points.
+for (let i = 0; i < BASE64_CHARS.length; i++) {
+  BASE64_LOOKUP[BASE64_CHARS.charCodeAt(i)] = i;
+}
+
+/**
+ * Encode a byte array in base64.
+ *
+ * @remarks
+ * We provide our own implementation so that we do not run into compatibility
+ * issues with node.js, different browsers etc.
+ * See:
+ * https://stackoverflow.com/questions/21797299/convert-base64-string-to-arraybuffer
+ *
+ * @param bytes - to be encoded
+ * @returns `bytes` encoded as base64 text
+ */
+export function base64Encode(bytes: Uint8Array): string {
+  // NOTE (mristin):
+  // This implementation is vaguely based on:
+  // https://github.com/danguer/blog-examples/blob/master/js/base64-binary.js,
+  // https://github.com/niklasvh/base64-arraybuffer/blob/master/src/index.ts and
+  // https://github.com/beatgammit/base64-js/blob/master/index.js.
+
+  // NOTE (mristin):
+  // We assume that string concatenation is actually *faster* than joining an array
+  // of strings, see:
+  // https://stackoverflow.com/questions/51185/are-javascript-strings-immutable-do-i-need-a-string-builder-in-javascript
+
+  if (bytes.length === 0) {
+    return "";
+  }
+
+  let encoded = '';
+  const len = bytes.length;
+
+  for (let i = 0; i < len; i += 3) {
+    encoded += BASE64_CHARS[bytes[i] >> 2];
+    encoded += BASE64_CHARS[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
+    encoded += BASE64_CHARS[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
+    encoded += BASE64_CHARS[bytes[i + 2] & 63];
+  }
+
+    // NOTE (mristin):
+    // We assume here that `substring` will be optimized for cases where we do not keep
+    // the original reference to the string. We tested a bit with
+    // https://www.measurethat.net/.
+
+  if (len % 3 === 2) {
+    encoded = encoded.substring(0, encoded.length - 1) + '=';
+  } else if (len % 3 === 1) {
+    encoded = encoded.substring(0, encoded.length - 2) + '==';
+  } else {
+    // No padding is necessary.
+  }
+
+  return encoded;
+}
+
+
+/**
+ * Decode a base64-encoded byte array.
+ *
+ * @remarks
+ * We provide our own implementation so that we do not run into compatibility
+ * issues with node.js, different browsers etc.
+ * See:
+ * https://stackoverflow.com/questions/21797299/convert-base64-string-to-arraybuffer
+ *
+ * @param text - to be decoded
+ * @returns either the array or an error, if `text` is not a valid base64 encoding
+ */
+export function base64Decode(text: string): Either<Uint8Array, string> {
+  // NOTE (mristin):
+  // This implementation is vaguely based on:
+  // https://github.com/danguer/blog-examples/blob/master/js/base64-binary.js,
+  // https://github.com/niklasvh/base64-arraybuffer/blob/master/src/index.ts and
+  // https://github.com/beatgammit/base64-js/blob/master/index.js.
+
+  const len = text.length;
+  let lenWoPad = len;
+
+  // NOTE (mristin):
+  // Some implementations forget the padding, so we try to be robust and check
+  // for the padding manually.
+  let bytesLength = text.length * 0.75;
+  if (text[len - 1] === '=') {
+    bytesLength--;
+    lenWoPad--;
+    if (text[len - 2] === '=') {
+      bytesLength--;
+      lenWoPad--;
+    }
+  }
+
+  const bytes = new Uint8Array(bytesLength);
+
+  const base64LookupLen = BASE64_LOOKUP.length;
+
+  let pointer = 0;
+
+  for (let i = 0; i < len; i += 4) {
+    // NOTE (mristin):
+    // Admittedly, this is very verbose code, but we want to be efficient, so we
+    // opted for performance over readability here.
+
+    const charCode0 = text.charCodeAt(i);
+    if (charCode0 >= base64LookupLen) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i}: ${text[i]} (code: ${charCode0})`
+      );
+    }
+    const encoded0 = BASE64_LOOKUP[charCode0];
+    if (encoded0 === 255) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i}: ${text[i]} (code: ${charCode0})`
+      );
+    }
+
+    const charCode1 = text.charCodeAt(i + 1);
+    if (charCode1 >= base64LookupLen) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 1}: ${text[i + 1]} (code: ${charCode1})`
+      );
+    }
+    const encoded1 = BASE64_LOOKUP[charCode1];
+    if (encoded1 === 255) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 1}: ${text[i + 1]} (code: ${charCode1})`
+      );
+    }
+
+    // We map padding to 65, which is the value of "A".
+    const charCode2 = i + 2 < lenWoPad ? text.charCodeAt(i + 2) : 65;
+    if (charCode2 >= base64LookupLen) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 2}: ${text[i + 2]} (code: ${charCode2})`
+      );
+    }
+    const encoded2 = BASE64_LOOKUP[charCode2];
+    if (encoded2 === 255) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 2}: ${text[i + 2]} (code: ${charCode2})`
+      );
+    }
+
+    // We map padding to 65, which is the value of "A".
+    const charCode3 = i + 3 < lenWoPad ? text.charCodeAt(i + 3) : 65;
+    if (charCode3 >= base64LookupLen) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 3}: ${text[i + 3]} (code: ${charCode3})`
+      );
+    }
+    const encoded3 = BASE64_LOOKUP[charCode3];
+    if (encoded3 === 255) {
+      return new Either<Uint8Array, string>(
+        null,
+        "Expected a valid character from base64-encoded string, " +
+          `but got at index ${i + 3}: ${text[i + 3]} (code: ${charCode3})`
+      );
+    }
+
+    bytes[pointer] = (encoded0 << 2) | (encoded1 >> 4);
+    pointer++;
+
+    bytes[pointer] = ((encoded1 & 15) << 4) | (encoded2 >> 2);
+    pointer++;
+
+    bytes[pointer] = ((encoded2 & 3) << 6) | (encoded3 & 63);
+    pointer++;
+  }
+
+// NOTE (mristin):
+// We expect Uint8Array to silently ignore writes outside of the buffer,
+// but we still want to check here in case the underlying platform was flaky about it.
+  if (bytes.length !== bytesLength) {
+    throw new Error(
+      `Expected bytes to have length ${bytesLength}, but got ${bytes.length}`
+    );
+  }
+
+  return new Either<Uint8Array, string>(bytes, null);
+}
+
+
+/**
+ * Encode a byte array in base64url.
+ *
+ * This encoding differs from base64 in so far that the characters `+` and `/` are
+ * replaced with `-` and `_` and the padding (`=`) is removed, so that the encoded
+ * value can be inserted into URIs without escaping.
+ *
+ * See RFC 4648 for more details:
+ * https://www.rfc-editor.org/rfc/rfc4648#section-5
+ *
+ * @param bytes - to be encoded
+ * @returns `bytes` encoded as base64url text
+ */
+export function base64UrlEncode(bytes: Uint8Array): string {
+  return base64Encode(bytes)
+    .replace(
+      /[+/=]/g,
+      m =>
+        m === '+'  ? '-' :
+        m === '/'  ? '_' :
+        '' // The padding `=` is removed.
+    );
+}
+
+
+/**
+ * Decode a base64url-encoded byte array.
+ *
+ * This encoding differs from base64 in so far that the characters `+` and `/` are
+ * replaced with `-` and `_` and the padding (`=`) is removed, so that the encoded
+ * value can be inserted into URIs without escaping.
+ *
+ * @param text - to be decoded
+ * @returns either the array or an error, if `text` is not a valid base64url encoding
+ */
+export function base64UrlDecode(text: string): Either<Uint8Array, string> {
+  let base64Text = text.replace(/[-_]/g, m => m === '-' ? '+' : '/');
+  const pad = base64Text.length % 4;
+  if (pad > 0) {
+    base64Text += '='.repeat(4 - pad);
+  }
+
+  return base64Decode(base64Text);
+}
+
+
+/**
+ * Check whether a surrogate pair starts at `offset` in `text`.
+ *
+ * @param text - to be inspected
+ * @param offset - in UTF-16 code units
+ * @returns whether a surrogate pair starts at `offset`
+ */
+function isSurrogatePairAt(text: string, offset: number): boolean {
+  if (offset + 1 >= text.length) {
+    return false;
+  }
+
+  const high = text.charCodeAt(offset);
+  const low = text.charCodeAt(offset + 1);
+  return high >= 0xd800 && high <= 0xdbff && low >= 0xdc00 && low <= 0xdfff;
+}
+
+
+/**
+ * Count the characters of `text` between the UTF-16 offsets `startOffset` and
+ * `endOffset`.
+ *
+ * @param text - to be inspected
+ * @param startOffset - in UTF-16 code units, inclusive
+ * @param endOffset - in UTF-16 code units, exclusive
+ * @returns the number of characters (code points)
+ */
+function countCharacters(
+  text: string,
+  startOffset: number,
+  endOffset: number
+): number {
+  let count = 0;
+  let offset = startOffset;
+  while (offset < endOffset) {
+    offset += isSurrogatePairAt(text, offset) ? 2 : 1;
+    count++;
+  }
+
+  return count;
+}
+
+
+/**
+ * Compute the UTF-16 offset of the character at `position` in `text`.
+ *
+ * @param text - to be inspected
+ * @param position - of the character, in characters (code points)
+ * @returns the offset in UTF-16 code units
+ */
+function offsetOf(text: string, position: number): number {
+  let offset = 0;
+  for (let i = 0; i < position; i++) {
+    offset += isSurrogatePairAt(text, offset) ? 2 : 1;
+  }
+
+  return offset;
+}
+
+
+/**
+ * Resolve `position` in a string of `length` as Python does in slicing.
+ *
+ * @remarks
+ * A negative position counts from the end, and the positions out of range are
+ * clamped to the string.
+ *
+ * @param position - to be resolved
+ * @param length - of the string
+ * @returns the resolved position within `[0, length]`
+ */
+function resolvePosition(position: number, length: number): number {
+  if (position < 0) {
+    return Math.max(position + length, 0);
+  }
+
+  return Math.min(position, length);
+}
+
+
+/**
+ * Count the characters (code points) of `text`.
+ *
+ * @remarks
+ * We follow the Python implementation of `len`, since Python is the language of
+ * the meta-model specifications. Hence, a character beyond the Basic
+ * Multilingual Plane counts as one, unlike in `text.length`.
+ *
+ * @param text - to be measured
+ * @returns the number of characters
+ */
+export function lenStr(text: string): number {
+  return countCharacters(text, 0, text.length);
+}
+
+
+/**
+ * Slice `text` from `start` up to `end`, exclusive.
+ *
+ * @remarks
+ * We follow the Python implementation of slicing, since Python is
+ * the language of the meta-model specifications. Hence, the positions count
+ * the characters (code points), a negative position counts from the end,
+ * the positions out of range are clamped to the string, and the slice is empty
+ * if `start` is not before `end`.
+ *
+ * @param text - to be sliced
+ * @param start - of the slice, inclusive
+ * @param end - of the slice, exclusive; if not given, the length of `text`
+ * @returns the slice
+ */
+export function sliceStr(text: string, start: number, end?: number): string {
+  const length = lenStr(text);
+  const theStart = resolvePosition(start, length);
+  const theEnd = end === undefined ? length : resolvePosition(end, length);
+
+  if (theStart >= theEnd) {
+    return "";
+  }
+
+  return text.substring(offsetOf(text, theStart), offsetOf(text, theEnd));
+}
+
+
+/**
+ * Find the first `sub` in `text` from `start` on.
+ *
+ * @remarks
+ * We follow the Python implementation of `str.find`, since Python is
+ * the language of the meta-model specifications. Hence, the positions count
+ * the characters (code points), a negative `start` counts from the end, and
+ * a `start` beyond the end of `text` gives -1.
+ *
+ * @param text - to be searched in
+ * @param sub - to be searched for
+ * @param start - of the search; if not given, the beginning of `text`
+ * @returns the position of `sub` in `text`, or -1 if `sub` could not be found
+ */
+export function findStr(text: string, sub: string, start = 0): number {
+  const length = lenStr(text);
+  const theStart = start < 0 ? Math.max(start + length, 0) : start;
+  if (theStart > length) {
+    return -1;
+  }
+
+  const startOffset = offsetOf(text, theStart);
+  const offset = text.indexOf(sub, startOffset);
+  if (offset === -1) {
+    return -1;
+  }
+
+  return theStart + countCharacters(text, startOffset, offset);
+}
+
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/constants.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/constants.ts
new file mode 100644
index 000000000..0107ee495
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/constants.ts
@@ -0,0 +1,15 @@
+/**
+ * Provide constant values of the meta-model.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/* eslint-disable @typescript-eslint/no-unused-vars */
+
+import * as OurTypes from "./types";
+
+/* eslint-enable @typescript-eslint/no-unused-vars */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/index.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/index.ts
new file mode 100644
index 000000000..a954b9203
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/index.ts
@@ -0,0 +1,23 @@
+/**
+ * Provide dummy SDK.
+ *
+ * @packageDocumentation
+ */
+
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+
+export * as common from "./common";
+export * as constants from "./constants";
+export * as jsonization from "./jsonization";
+export * as xmlcommon from "./xmlcommon";
+export * as xmlization from "./xmlization";
+export * as stringification from "./stringification";
+export * as types from "./types";
+export * as verification from "./verification";
+
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/jsonization.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/jsonization.ts
new file mode 100644
index 000000000..9329b5ee1
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/jsonization.ts
@@ -0,0 +1,1459 @@
+/**
+ * Provide de/serialization of meta-model classes to/from JSON.
+ *
+ * We can not use one-pass deserialization for JSON since the object
+ * properties do not have fixed order, and hence we can not read
+ * `modelType` property ahead of the remaining properties.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurCommon from "./common";
+import * as OurTypes from "./types";
+import * as OurStringification from "./stringification";
+
+export type JsonValue = string | number | boolean | JsonObject | JsonArray;
+
+export type JsonArray = Iterable<JsonValue>;
+export type JsonObject = { [prop: string]: JsonValue };
+
+// NOTE (mristin):
+// The SDK defines three of these path vocabularies: this one, the one in
+// the `jsonization` module, and the one in the `xmlcommon` module. They look
+// alike, and it is tempting to merge them, but they are not interchangeable.
+//
+// Each of them points into a different thing:
+//
+// * This one points into the instances which you built, so a property segment
+//   holds a class of the meta-model.
+// * The jsonization's points into the JSON-able structure being read or
+//   written, so a property segment holds the JSON-able object instead: while
+//   a document is being parsed, the instance which the property would belong
+//   to does not exist yet.
+// * The xmlcommon's points into the XML document, where there are no
+//   properties at all, only elements, so it names an element instead. It is
+//   also the only one whose segments carry no back-pointer, as the reading is
+//   a single pass over a token stream and the element is gone by the time
+//   the error comes back out.
+//
+// The three also render differently: a path into the instances is
+// a TypeScript access expression, a path into a JSON-able structure starts at
+// the root of the document and carries no leading dot, and a path into an XML
+// document is a relative XPath.
+//
+// Merging them would mean either dropping the back-pointers, which have been
+// part of the public API of this SDK since before these modules were split
+// apart, or defining a single path over the union of all the segment kinds --
+// in which case every consumer would have to handle segments which can never
+// occur in its world. Three small vocabularies which each say exactly what
+// they can say cost less than one large one which lies about its range.
+
+/**
+ * Represent a property on a path to the erroneous value.
+ */
+export class PropertySegment {
+  /**
+   * Instance that contains the property
+   */
+  readonly instance: JsonObject;
+
+  /**
+   * Name of the property
+   */
+  readonly name: string;
+
+  constructor(instance: JsonObject, name: string) {
+    this.instance = instance;
+    this.name = name;
+  }
+}
+
+/**
+ * Represent an index access on a path to the erroneous value.
+ */
+export class IndexSegment {
+  /**
+   * Container that contains the item
+   */
+  readonly container: JsonArray;
+
+  /**
+   * Index of the item
+   */
+  readonly index: number;
+
+  constructor(container: JsonArray, index: number) {
+    if (!Number.isInteger(index)) {
+      throw new Error(`Expected an integer for the index, but got: ${index}`);
+    }
+
+    this.container = container;
+    this.index = index;
+  }
+}
+
+/**
+ * Represent a member of an open JSON-able object on a path to the erroneous
+ * value.
+ *
+ * @remarks
+ *
+ * Unlike a {@link PropertySegment}, which names a property of one of our
+ * classes, a key names a member of an open JSON-able object. It is known only
+ * at run time, and can be any string at all, so it is always rendered as
+ * a subscript.
+ */
+export class KeySegment {
+  /**
+   * Object that contains the value at {@link key}
+   */
+  readonly object: JsonObject;
+
+  /**
+   * Key of the value
+   */
+  readonly key: string;
+
+  constructor(object: JsonObject, key: string) {
+    this.object = object;
+    this.key = key;
+  }
+}
+
+export type Segment = PropertySegment | IndexSegment | KeySegment;
+
+/**
+ * Match the property names which a path writes after a dot; the other names
+ * are written in brackets as JSON strings, *e.g.*, `["$eq"]`.
+ */
+const VARIABLE_NAME_RE = /^[a-zA-Z_][a-zA-Z_0-9]*$/;
+
+/**
+ * Represent the relative path to the erroneous value.
+ */
+export class Path {
+  private readonly _segments = new Array<Segment>();
+
+  /**
+   * Get the segments of the path.
+   */
+  segments(): Array<Segment> {
+    return this._segments;
+  }
+
+  /**
+   * Insert the `segment` in front of the {@link segments}.
+   *
+   * @param segment - segment to be prepended to {@link segments}
+   */
+  prepend(segment: Segment): void {
+    this._segments.unshift(segment);
+  }
+
+  toString(): string {
+    if (this._segments.length === 0) {
+      return "";
+    }
+
+    const parts = new Array<string>();
+
+    let segment = this._segments[0];
+
+    if (segment instanceof PropertySegment) {
+      parts.push(
+        VARIABLE_NAME_RE.test(segment.name)
+          ? segment.name
+          : `[${JSON.stringify(segment.name)}]`
+      );
+    } else if (segment instanceof IndexSegment) {
+      parts.push(`[${segment.index}]`);
+    } else if (segment instanceof KeySegment) {
+      parts.push(`[${JSON.stringify(segment.key)}]`);
+    } else {
+      throw new Error(`Unexpected segment: ${segment}`);
+    }
+
+    for (let i = 1; i < this._segments.length; i++) {
+      segment = this._segments[i];
+      if (segment instanceof PropertySegment) {
+        parts.push(
+          VARIABLE_NAME_RE.test(segment.name)
+            ? `.${segment.name}`
+            : `[${JSON.stringify(segment.name)}]`
+        );
+      } else if (segment instanceof IndexSegment) {
+        parts.push(`[${segment.index}]`);
+      } else if (segment instanceof KeySegment) {
+        parts.push(`[${JSON.stringify(segment.key)}]`);
+      } else {
+        throw new Error(`Unexpected segment: ${segment}`);
+      }
+    }
+
+    return parts.join("");
+  }
+}
+
+// region De-serialization
+
+/**
+ * Signal that the JSON de-serialization could not be performed.
+ */
+export class DeserializationError {
+  /**
+   * Human-readable explanation of the error
+   */
+  readonly message: string;
+
+  /**
+   * Relative path to the erroneous value
+   */
+  readonly path: Path;
+
+  constructor(message: string, path: Path | null = null) {
+    this.message = message;
+    this.path = path ?? new Path();
+  }
+}
+
+/**
+ * Create an error as {@link common.Either}.
+ *
+ * @param message - human-readable explanation of the error
+ * @returns An {@link common.Either } with the error set
+ * @typeParam T - type of the value if there had been no error
+ */
+function newDeserializationError<T>(
+  message: string
+): OurCommon.Either<T, DeserializationError> {
+  return new OurCommon.Either<T, DeserializationError>(
+    null,
+    new DeserializationError(message)
+  );
+}
+
+/**
+ * Check that `jsonable` looks like a JSON object, without parsing it.
+ *
+ * @param jsonable - to be checked
+ * @returns error, if any
+ */
+function checkIsJsonObject(jsonable: JsonValue): DeserializationError | null {
+  if (jsonable === null) {
+    return new DeserializationError(
+      "Expected a JSON object, but got null"
+    );
+  }
+  if (Array.isArray(jsonable)) {
+    return new DeserializationError(
+      "Expected a JSON object, but got a JSON array"
+    );
+  }
+  if (typeof jsonable !== "object") {
+    return new DeserializationError(
+      `Expected a JSON object, but got: ${typeof jsonable}`
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Extract the `modelType` property of `jsonObject`.
+ *
+ * @param jsonObject - to be inspected
+ * @returns the model type, or an error
+ */
+function extractModelType(
+  jsonObject: JsonObject
+): OurCommon.Either<string, DeserializationError> {
+  const modelType = jsonObject["modelType"];
+  if (modelType === undefined) {
+    return newDeserializationError<string>(
+      "The required property 'modelType' is missing"
+    );
+  }
+  if (typeof modelType !== "string") {
+    // NOTE (mristin):
+    // A model type of a wrong type is reported at the property, as the type
+    // errors of all the other properties are, and as in the other SDKs.
+    const error = new DeserializationError(
+      `Expected the property modelType to be a string, ` +
+      `but got: ${typeof modelType}`
+    );
+    error.path.prepend(new PropertySegment(jsonObject, "modelType"));
+    return new OurCommon.Either<string, DeserializationError>(null, error);
+  }
+
+  return new OurCommon.Either<string, DeserializationError>(modelType, null);
+}
+
+/**
+ * Check that the `modelType` property of `jsonObject` is `expected`.
+ *
+ * @param jsonObject - to be inspected
+ * @param expected - expected model type
+ * @returns error, if any
+ */
+function checkModelType(
+  jsonObject: JsonObject,
+  expected: string
+): DeserializationError | null {
+  const modelTypeOrError = extractModelType(jsonObject);
+  if (modelTypeOrError.error !== null) {
+    return modelTypeOrError.error;
+  }
+
+  const modelType = modelTypeOrError.mustValue();
+  if (modelType !== expected) {
+    return new DeserializationError(
+      `Expected model type '${expected}', ` +
+      `but got: ${modelType}`
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Check that `jsonable` looks like an iterable which can be parsed
+ * item-by-item, without consuming it.
+ *
+ * @param jsonable - to be checked
+ * @returns error, if any
+ */
+function checkIsIterable(jsonable: JsonValue): DeserializationError | null {
+  if (jsonable === null) {
+    return new DeserializationError(
+      "Expected an iterable, but got null"
+    );
+  }
+  if (typeof jsonable !== "object") {
+    return new DeserializationError(
+      `Expected an iterable, but got: ${typeof jsonable}`
+    );
+  }
+  if (typeof jsonable[Symbol.iterator] !== "function") {
+    return new DeserializationError(
+      "Expected an iterable with iterator function, " +
+        `but got iterator of type: ${typeof jsonable[Symbol.iterator]}`
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Parse `jsonable` as an array, and every one of its items with `parseItem`.
+ *
+ * @param jsonable - to be parsed item-by-item
+ * @param parseItem - to parse a single item of `jsonable`
+ * @returns parsed items, or an error
+ * @typeParam T - type of a single parsed item
+ */
+function parseArray<T>(
+  jsonable: JsonValue,
+  parseItem: (
+    jsonableItem: JsonValue
+  ) => OurCommon.Either<T, DeserializationError>
+): OurCommon.Either<Array<T>, DeserializationError> {
+  const iterableError = checkIsIterable(jsonable);
+  if (iterableError !== null) {
+    return new OurCommon.Either<Array<T>, DeserializationError>(
+      null,
+      iterableError
+    );
+  }
+
+  const iterable = <Iterable<JsonValue>>jsonable;
+
+  const items = new Array<T>();
+  let i = 0;
+  for (const jsonableItem of iterable) {
+    const itemOrError = parseItem(jsonableItem);
+    if (itemOrError.error !== null) {
+      itemOrError.error.path.prepend(new IndexSegment(iterable, i));
+      return new OurCommon.Either<Array<T>, DeserializationError>(
+        null,
+        itemOrError.error
+      );
+    }
+    items.push(itemOrError.mustValue());
+    i++;
+  }
+  return new OurCommon.Either<Array<T>, DeserializationError>(items, null);
+}
+
+/**
+ * Parse `jsonable` as a boolean.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed boolean value, or an error
+ */
+function booleanFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<boolean, DeserializationError> {
+  // `typeof` seems to be optimized these days, so we use it instead of
+  // literal comparison, see:
+  // https://stackoverflow.com/questions/61786250/is-typeof-faster-than-literal-comparison
+
+  if (jsonable === null) {
+    return newDeserializationError<boolean>(
+      "Expected a boolean, but got null"
+    );
+  }
+  if (typeof jsonable !== "boolean") {
+    return newDeserializationError<boolean>(
+      `Expected a boolean, but got ${typeof jsonable}`
+    );
+  }
+
+  return new OurCommon.Either<boolean, DeserializationError>(jsonable, null);
+}
+
+/**
+ * Parse `jsonable` as an integer.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed integer value, or an error
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function integerFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<number, DeserializationError> {
+  if (jsonable === null) {
+    return newDeserializationError<number>(
+      "Expected an integer number, but got null"
+    );
+  }
+  if (typeof jsonable !== "number") {
+    return newDeserializationError<number>(
+      `Expected an integer number, but got: ${typeof jsonable}`
+    );
+  }
+
+  if (!Number.isInteger(jsonable)) {
+    return newDeserializationError<number>(
+      `Expected an integer number, but got: ${jsonable}`
+    );
+  }
+
+  return new OurCommon.Either<number, DeserializationError>(jsonable, null);
+}
+
+/**
+ * Parse `jsonable` as a number.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed numeric value, or an error
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+function numberFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<number, DeserializationError> {
+  if (jsonable === null) {
+    return newDeserializationError<number>(
+      "Expected a number, but got null"
+    );
+  }
+  if (typeof jsonable !== "number") {
+    return newDeserializationError<number>(
+      `Expected a number, but got: ${typeof jsonable}`
+    );
+  }
+
+  // NOTE (mristin):
+  // JSON knows neither an infinity nor a not-a-number, so a conformant parser
+  // can never give us one. The caller can still hand us a JSON-able which has
+  // been constructed programmatically, so we have to check here.
+  if (!Number.isFinite(jsonable)) {
+    return newDeserializationError<number>(
+      `Expected a finite number, but got: ${jsonable}`
+    );
+  }
+
+  return new OurCommon.Either<number, DeserializationError>(jsonable, null);
+}
+
+/**
+ * Parse `jsonable` as a string.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed string value, or an error
+ */
+function stringFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<string, DeserializationError> {
+  if (jsonable === null) {
+    return newDeserializationError<string>(
+      "Expected a string, but got null"
+    );
+  }
+  if (typeof jsonable !== "string") {
+    return newDeserializationError<string>(
+      `Expected a string, but got: ${typeof jsonable}`
+    );
+  }
+
+  return new OurCommon.Either<string, DeserializationError>(jsonable, null);
+}
+
+/**
+ * Parse `jsonable` as a byte array.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed byte array, or an error
+ */
+function bytesFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<Uint8Array, DeserializationError> {
+  if (jsonable === null) {
+    return newDeserializationError<Uint8Array>(
+      "Expected a base64-encoded string, but got null"
+    );
+  }
+  if (typeof jsonable !== "string") {
+    return newDeserializationError<Uint8Array>(
+      `Expected a base64-encoded string, but got: ${typeof jsonable}`
+    );
+  }
+
+  const either = OurCommon.base64Decode(jsonable);
+  if (either.error !== null) {
+    return newDeserializationError<Uint8Array>(either.error);
+  }
+  return new OurCommon.Either<Uint8Array, DeserializationError>(
+    either.mustValue(), null
+  );
+}
+
+/**
+ * Parse `jsonable` as an instance
+ * of {@link types!IItem}.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed instance, or error if `jsonable` is invalid
+ */
+export function itemFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<
+  OurTypes.IItem,
+  DeserializationError
+> {
+  const objectError = checkIsJsonObject(jsonable);
+  if (objectError !== null) {
+    return new OurCommon.Either<
+      OurTypes.IItem,
+      DeserializationError
+    >(
+      null,
+      objectError
+    );
+  }
+  const jsonObject = <JsonObject>jsonable;
+
+  const modelTypeOrError = extractModelType(jsonObject);
+  if (modelTypeOrError.error !== null) {
+    return new OurCommon.Either<
+      OurTypes.IItem,
+      DeserializationError
+    >(
+      null,
+      modelTypeOrError.error
+    );
+  }
+
+  const modelType = modelTypeOrError.mustValue();
+
+  switch (modelType) {
+    case "SomeItem":
+      return parsePropertiesOfSomeItem(jsonObject);
+
+    case "SpecialItem":
+      return parsePropertiesOfSpecialItem(jsonObject);
+
+    default:
+      return newDeserializationError<OurTypes.IItem>(
+        `Unexpected model type for IItem: ${modelType}`
+      );
+  }
+}
+
+/**
+ * Parse the properties of an instance
+ * of {@link types!SomeItem} from `jsonObject`.
+ *
+ * The `modelType` is expected to have been already verified by the caller,
+ * and is therefore skipped here.
+ *
+ * @param jsonObject - JSON object to be parsed
+ * @returns parsed instance of {@link types!SomeItem},
+ * or an error if any
+ */
+function parsePropertiesOfSomeItem(
+  jsonObject: JsonObject
+): OurCommon.Either<
+  OurTypes.SomeItem,
+  DeserializationError
+> {
+  let theName: string | null = null;
+  let theNickname: string | null = null;
+
+  for (const key in jsonObject) {
+    const jsonableValue = jsonObject[key];
+
+    let propertyError: DeserializationError | null = null;
+    switch (key) {
+      case "name": {
+        const parsed = stringFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theName = parsed.value;
+        break;
+      }
+
+      case "nickname": {
+        const parsed = stringFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theNickname = parsed.value;
+        break;
+      }
+
+      case "modelType": {
+        // The model type has already been verified by the caller.
+        break;
+      }
+
+      // NOTE (mristin):
+      // Since we conflate here a JavaScript object with a JSON object, we ignore
+      // properties which we do not know how to de-serialize and assume they are
+      // related to the *JavaScript* properties of the object or `Object` prototype.
+      default: {
+        continue;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(
+        new PropertySegment(jsonObject, key)
+      );
+      return new OurCommon.Either<
+        OurTypes.SomeItem,
+        DeserializationError
+      >(
+        null,
+        propertyError
+      );
+    }
+  }
+
+  if (theName === null) {
+    return newDeserializationError<
+      OurTypes.SomeItem
+    >(
+      "The required property 'name' is missing"
+    );
+  }
+
+  return new OurCommon.Either<
+    OurTypes.SomeItem,
+    DeserializationError
+  >(
+    new OurTypes.SomeItem(
+      theName,
+      theNickname
+    ),
+    null
+  );
+}
+
+/**
+ * Parse `jsonable` as an instance
+ * of {@link types!ISomeItem}.
+ *
+ * @param jsonable - to be parsed
+ * @returns parsed instance, or error if `jsonable` is invalid
+ */
+export function someItemFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<
+  OurTypes.ISomeItem,
+  DeserializationError
+> {
+  const objectError = checkIsJsonObject(jsonable);
+  if (objectError !== null) {
+    return new OurCommon.Either<
+      OurTypes.ISomeItem,
+      DeserializationError
+    >(
+      null,
+      objectError
+    );
+  }
+  const jsonObject = <JsonObject>jsonable;
+
+  const modelTypeOrError = extractModelType(jsonObject);
+  if (modelTypeOrError.error !== null) {
+    return new OurCommon.Either<
+      OurTypes.ISomeItem,
+      DeserializationError
+    >(
+      null,
+      modelTypeOrError.error
+    );
+  }
+
+  const modelType = modelTypeOrError.mustValue();
+
+  switch (modelType) {
+    case "SpecialItem":
+      return parsePropertiesOfSpecialItem(jsonObject);
+
+    case "SomeItem":
+      return parsePropertiesOfSomeItem(jsonObject);
+
+    default:
+      return newDeserializationError<OurTypes.ISomeItem>(
+        `Unexpected model type for ISomeItem: ${modelType}`
+      );
+  }
+}
+
+/**
+ * Parse the properties of an instance
+ * of {@link types!SpecialItem} from `jsonObject`.
+ *
+ * The `modelType` is expected to have been already verified by the caller,
+ * and is therefore skipped here.
+ *
+ * @param jsonObject - JSON object to be parsed
+ * @returns parsed instance of {@link types!SpecialItem},
+ * or an error if any
+ */
+function parsePropertiesOfSpecialItem(
+  jsonObject: JsonObject
+): OurCommon.Either<
+  OurTypes.SpecialItem,
+  DeserializationError
+> {
+  let theName: string | null = null;
+  let theNickname: string | null = null;
+  let theLevel: number | null = null;
+
+  for (const key in jsonObject) {
+    const jsonableValue = jsonObject[key];
+
+    let propertyError: DeserializationError | null = null;
+    switch (key) {
+      case "name": {
+        const parsed = stringFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theName = parsed.value;
+        break;
+      }
+
+      case "nickname": {
+        const parsed = stringFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theNickname = parsed.value;
+        break;
+      }
+
+      case "level": {
+        const parsed = integerFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theLevel = parsed.value;
+        break;
+      }
+
+      case "modelType": {
+        // The model type has already been verified by the caller.
+        break;
+      }
+
+      // NOTE (mristin):
+      // Since we conflate here a JavaScript object with a JSON object, we ignore
+      // properties which we do not know how to de-serialize and assume they are
+      // related to the *JavaScript* properties of the object or `Object` prototype.
+      default: {
+        continue;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(
+        new PropertySegment(jsonObject, key)
+      );
+      return new OurCommon.Either<
+        OurTypes.SpecialItem,
+        DeserializationError
+      >(
+        null,
+        propertyError
+      );
+    }
+  }
+
+  if (theName === null) {
+    return newDeserializationError<
+      OurTypes.SpecialItem
+    >(
+      "The required property 'name' is missing"
+    );
+  }
+
+  if (theLevel === null) {
+    return newDeserializationError<
+      OurTypes.SpecialItem
+    >(
+      "The required property 'level' is missing"
+    );
+  }
+
+  return new OurCommon.Either<
+    OurTypes.SpecialItem,
+    DeserializationError
+  >(
+    new OurTypes.SpecialItem(
+      theName,
+      theLevel,
+      theNickname
+    ),
+    null
+  );
+}
+
+/**
+ * Parse an instance of {@link types!SpecialItem} from the JSON-able
+ * structure `jsonable`.
+ *
+ * @param jsonable - structure to be parsed
+ * @returns parsed instance of {@link types!SpecialItem},
+ * or an error if any
+ */
+export function specialItemFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<
+  OurTypes.SpecialItem,
+  DeserializationError
+> {
+  const objectError = checkIsJsonObject(jsonable);
+  if (objectError !== null) {
+    return new OurCommon.Either<
+      OurTypes.SpecialItem,
+      DeserializationError
+    >(
+      null,
+      objectError
+    );
+  }
+  const jsonObject = <JsonObject>jsonable;
+
+  const modelTypeError = checkModelType(jsonObject, "SpecialItem");
+  if (modelTypeError !== null) {
+    return new OurCommon.Either<
+      OurTypes.SpecialItem,
+      DeserializationError
+    >(
+      null,
+      modelTypeError
+    );
+  }
+
+  return parsePropertiesOfSpecialItem(jsonObject);
+}
+
+/**
+ * Parse the properties of an instance
+ * of {@link types!Container} from `jsonObject`.
+ *
+ * @param jsonObject - JSON object to be parsed
+ * @returns parsed instance of {@link types!Container},
+ * or an error if any
+ */
+function parsePropertiesOfContainer(
+  jsonObject: JsonObject
+): OurCommon.Either<
+  OurTypes.Container,
+  DeserializationError
+> {
+  let theItems: Array<OurTypes.IItem> | null = null;
+  let theSomeItems: Array<OurTypes.SomeItem> | null = null;
+  let theSpecialItems: Array<OurTypes.SpecialItem> | null = null;
+
+  for (const key in jsonObject) {
+    const jsonableValue = jsonObject[key];
+
+    let propertyError: DeserializationError | null = null;
+    switch (key) {
+      case "items": {
+        const parsed = parseArray(
+          jsonableValue,
+          itemFromJsonable
+        );
+        propertyError = parsed.error;
+        theItems = parsed.value;
+        break;
+      }
+
+      case "someItems": {
+        const parsed = parseArray(
+          jsonableValue,
+          someItemFromJsonable
+        );
+        propertyError = parsed.error;
+        theSomeItems = parsed.value;
+        break;
+      }
+
+      case "specialItems": {
+        const parsed = parseArray(
+          jsonableValue,
+          specialItemFromJsonable
+        );
+        propertyError = parsed.error;
+        theSpecialItems = parsed.value;
+        break;
+      }
+
+      // NOTE (mristin):
+      // Since we conflate here a JavaScript object with a JSON object, we ignore
+      // properties which we do not know how to de-serialize and assume they are
+      // related to the *JavaScript* properties of the object or `Object` prototype.
+      default: {
+        continue;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(
+        new PropertySegment(jsonObject, key)
+      );
+      return new OurCommon.Either<
+        OurTypes.Container,
+        DeserializationError
+      >(
+        null,
+        propertyError
+      );
+    }
+  }
+
+  if (theItems === null) {
+    return newDeserializationError<
+      OurTypes.Container
+    >(
+      "The required property 'items' is missing"
+    );
+  }
+
+  if (theSomeItems === null) {
+    return newDeserializationError<
+      OurTypes.Container
+    >(
+      "The required property 'someItems' is missing"
+    );
+  }
+
+  return new OurCommon.Either<
+    OurTypes.Container,
+    DeserializationError
+  >(
+    new OurTypes.Container(
+      theItems,
+      theSomeItems,
+      theSpecialItems
+    ),
+    null
+  );
+}
+
+/**
+ * Parse an instance of {@link types!Container} from the JSON-able
+ * structure `jsonable`.
+ *
+ * @param jsonable - structure to be parsed
+ * @returns parsed instance of {@link types!Container},
+ * or an error if any
+ */
+export function containerFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<
+  OurTypes.Container,
+  DeserializationError
+> {
+  const objectError = checkIsJsonObject(jsonable);
+  if (objectError !== null) {
+    return new OurCommon.Either<
+      OurTypes.Container,
+      DeserializationError
+    >(
+      null,
+      objectError
+    );
+  }
+  const jsonObject = <JsonObject>jsonable;
+
+  return parsePropertiesOfContainer(jsonObject);
+}
+
+/**
+ * Parse the properties of an instance
+ * of {@link types!Wrapper} from `jsonObject`.
+ *
+ * @param jsonObject - JSON object to be parsed
+ * @returns parsed instance of {@link types!Wrapper},
+ * or an error if any
+ */
+function parsePropertiesOfWrapper(
+  jsonObject: JsonObject
+): OurCommon.Either<
+  OurTypes.Wrapper,
+  DeserializationError
+> {
+  let theContainer: OurTypes.Container | null = null;
+
+  for (const key in jsonObject) {
+    const jsonableValue = jsonObject[key];
+
+    let propertyError: DeserializationError | null = null;
+    switch (key) {
+      case "container": {
+        const parsed = containerFromJsonable(
+          jsonableValue
+        );
+        propertyError = parsed.error;
+        theContainer = parsed.value;
+        break;
+      }
+
+      // NOTE (mristin):
+      // Since we conflate here a JavaScript object with a JSON object, we ignore
+      // properties which we do not know how to de-serialize and assume they are
+      // related to the *JavaScript* properties of the object or `Object` prototype.
+      default: {
+        continue;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(
+        new PropertySegment(jsonObject, key)
+      );
+      return new OurCommon.Either<
+        OurTypes.Wrapper,
+        DeserializationError
+      >(
+        null,
+        propertyError
+      );
+    }
+  }
+
+  if (theContainer === null) {
+    return newDeserializationError<
+      OurTypes.Wrapper
+    >(
+      "The required property 'container' is missing"
+    );
+  }
+
+  return new OurCommon.Either<
+    OurTypes.Wrapper,
+    DeserializationError
+  >(
+    new OurTypes.Wrapper(
+      theContainer
+    ),
+    null
+  );
+}
+
+/**
+ * Parse an instance of {@link types!Wrapper} from the JSON-able
+ * structure `jsonable`.
+ *
+ * @param jsonable - structure to be parsed
+ * @returns parsed instance of {@link types!Wrapper},
+ * or an error if any
+ */
+export function wrapperFromJsonable(
+  jsonable: JsonValue
+): OurCommon.Either<
+  OurTypes.Wrapper,
+  DeserializationError
+> {
+  const objectError = checkIsJsonObject(jsonable);
+  if (objectError !== null) {
+    return new OurCommon.Either<
+      OurTypes.Wrapper,
+      DeserializationError
+    >(
+      null,
+      objectError
+    );
+  }
+  const jsonObject = <JsonObject>jsonable;
+
+  return parsePropertiesOfWrapper(jsonObject);
+}
+
+// endregion
+
+// region Serialization
+
+/**
+ * Signal that the JSON serialization could not be performed.
+ *
+ * The {@link SerializationError.path} points into the instance which was to be
+ * serialized, and *not* into a JSON document -- at the point of the failure,
+ * there is no document yet. For example, `.submodels[0].value` tells you that
+ * the serialization broke on `that.submodels[0].value`.
+ *
+ * Mind that this path is a plain string, unlike the structured
+ * {@link Path} of the de-serialization. A segment of the latter carries
+ * the JSON value it was read from, and while serializing there is no such
+ * value to carry.
+ */
+export class SerializationError extends Error {
+  private readonly _segments = new Array<string>();
+
+  /**
+   * Render the path to the erroneous value as a TypeScript access expression.
+   */
+  get path(): string {
+    return this._segments.join("");
+  }
+
+  /**
+   * Insert the access to the property `name` before the {@link path}.
+   */
+  prependProperty(name: string): void {
+    this._segments.unshift(`.${name}`);
+  }
+
+  /**
+   * Insert the access to the item at `index` before the {@link path}.
+   */
+  prependIndex(index: number): void {
+    this._segments.unshift(`[${index}]`);
+  }
+
+  /**
+   * Insert the access to the member `key` before the {@link path}.
+   *
+   * @remarks
+   *
+   * Unlike a property of one of our classes, a member of an open JSON-able
+   * object is known only at run time and can be any string at all, so it is
+   * always rendered as a subscript.
+   */
+  prependKey(key: string): void {
+    this._segments.unshift(`[${JSON.stringify(key)}]`);
+  }
+}
+
+/**
+ * Serialize `that` integer to a JSON-able value.
+ *
+ * Only the integers in the range [-2^53 + 1, 2^53 - 1] are serialized. Outside
+ * of it, an integer can not be exactly represented as a 64-bit floating-point
+ * number, which is what the JSON de-serializers of the other languages read
+ * a number into.
+ *
+ * @param that - integer to be serialized
+ * @returns `that`, unchanged
+ * @throws {@link SerializationError} if outside the range
+ */
+function integerToJsonable(that: number): number {
+  if (!Number.isFinite(that) || that < -9007199254740991 || that > 9007199254740991) {
+    throw new SerializationError(
+      `The integer can not be serialized to JSON as it is outside ` +
+        `the range [-2^53 + 1, 2^53 - 1]: ${that}`
+    );
+  }
+  return that;
+}
+
+/**
+ * Serialize `that` to a JSON-able representation.
+ *
+ * @param that - instance to be serialized
+ * @returns JSON-able representation
+ */
+function serializeSomeItem(
+  that: OurTypes.SomeItem
+): JsonObject {
+  const jsonable: JsonObject = {};
+
+  // The property being serialized, for the path of a failure.
+  let prop = "";
+  try {
+    prop = "name";
+    jsonable["name"] =
+      that.name;
+
+    if (that.nickname !== null) {
+      prop = "nickname";
+      jsonable["nickname"] =
+        that.nickname;
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependProperty(prop);
+    }
+    throw error;
+  }
+
+  jsonable["modelType"] = "SomeItem";
+
+  return jsonable;
+}
+
+/**
+ * Serialize `that` to a JSON-able representation.
+ *
+ * @param that - instance to be serialized
+ * @returns JSON-able representation
+ */
+function serializeSpecialItem(
+  that: OurTypes.SpecialItem
+): JsonObject {
+  const jsonable: JsonObject = {};
+
+  // The property being serialized, for the path of a failure.
+  let prop = "";
+  try {
+    prop = "name";
+    jsonable["name"] =
+      that.name;
+
+    if (that.nickname !== null) {
+      prop = "nickname";
+      jsonable["nickname"] =
+        that.nickname;
+    }
+
+    prop = "level";
+    jsonable["level"] =
+      integerToJsonable(that.level);
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependProperty(prop);
+    }
+    throw error;
+  }
+
+  jsonable["modelType"] = "SpecialItem";
+
+  return jsonable;
+}
+
+/**
+ * Serialize `that` to a JSON-able representation.
+ *
+ * @param that - instance to be serialized
+ * @returns JSON-able representation
+ */
+function serializeContainer(
+  that: OurTypes.Container
+): JsonObject {
+  const jsonable: JsonObject = {};
+
+  // The property being serialized, for the path of a failure.
+  let prop = "";
+  try {
+    prop = "items";
+    jsonable["items"] =
+      serialize_ListOf_IItem(that.items);
+
+    prop = "someItems";
+    jsonable["someItems"] =
+      serialize_ListOf_SomeItem(that.someItems);
+
+    if (that.specialItems !== null) {
+      prop = "specialItems";
+      jsonable["specialItems"] =
+        serialize_ListOf_SpecialItem(that.specialItems);
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependProperty(prop);
+    }
+    throw error;
+  }
+
+  return jsonable;
+}
+
+/**
+ * Serialize `that` to a JSON-able representation.
+ *
+ * @param that - instance to be serialized
+ * @returns JSON-able representation
+ */
+function serializeWrapper(
+  that: OurTypes.Wrapper
+): JsonObject {
+  const jsonable: JsonObject = {};
+
+  // The property being serialized, for the path of a failure.
+  let prop = "";
+  try {
+    prop = "container";
+    jsonable["container"] =
+      serializeContainer(that.container);
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependProperty(prop);
+    }
+    throw error;
+  }
+
+  return jsonable;
+}
+
+/**
+ * Serialize `that` to a JSON-able array.
+ *
+ * @param that - list to be serialized
+ * @returns JSON-able array
+ */
+function serialize_ListOf_IItem(
+  that: ReadonlyArray<OurTypes.IItem>
+): Array<JsonObject> {
+  const result = new Array<JsonObject>(that.length);
+  let i = 0;
+  try {
+    for (; i < that.length; i++) {
+      result[i] = serializeClass(that[i]);
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependIndex(i);
+    }
+    throw error;
+  }
+  return result;
+}
+
+/**
+ * Serialize `that` to a JSON-able array.
+ *
+ * @param that - list to be serialized
+ * @returns JSON-able array
+ */
+function serialize_ListOf_SomeItem(
+  that: ReadonlyArray<OurTypes.SomeItem>
+): Array<JsonObject> {
+  const result = new Array<JsonObject>(that.length);
+  let i = 0;
+  try {
+    for (; i < that.length; i++) {
+      result[i] = serializeClass(that[i]);
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependIndex(i);
+    }
+    throw error;
+  }
+  return result;
+}
+
+/**
+ * Serialize `that` to a JSON-able array.
+ *
+ * @param that - list to be serialized
+ * @returns JSON-able array
+ */
+function serialize_ListOf_SpecialItem(
+  that: ReadonlyArray<OurTypes.SpecialItem>
+): Array<JsonObject> {
+  const result = new Array<JsonObject>(that.length);
+  let i = 0;
+  try {
+    for (; i < that.length; i++) {
+      result[i] = serializeSpecialItem(that[i]);
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependIndex(i);
+    }
+    throw error;
+  }
+  return result;
+}
+
+/**
+ * Dispatch the serialization on the run-time type of an instance.
+ */
+class Serializer extends OurTypes.AbstractTransformer<JsonObject> {
+  transformSomeItem(
+    that: OurTypes.SomeItem
+  ): JsonObject {
+    return serializeSomeItem(that);
+  }
+
+  transformSpecialItem(
+    that: OurTypes.SpecialItem
+  ): JsonObject {
+    return serializeSpecialItem(that);
+  }
+
+  transformContainer(
+    that: OurTypes.Container
+  ): JsonObject {
+    return serializeContainer(that);
+  }
+
+  transformWrapper(
+    that: OurTypes.Wrapper
+  ): JsonObject {
+    return serializeWrapper(that);
+  }
+}
+
+const SERIALIZER = new Serializer();
+
+/**
+ * Serialize `that` to a JSON-able representation.
+ *
+ * Which JSON object that is, is decided by the run-time type of `that`, so this
+ * one function serves an abstract class, a concrete class with descendants and
+ * a named union alike. The de-serialization, which has to decide what to construct
+ * before it has read anything, needs a dispatcher per type instead.
+ *
+ * @param that - instance to be serialized
+ * @returns JSON-able representation
+ */
+function serializeClass(that: OurTypes.Class): JsonObject {
+  return that.transform(SERIALIZER);
+}
+
+/**
+ * Convert `that` to a JSON-able structure.
+ *
+ * @param that - Model instance to be recursively converted to a JSON-able structure
+ * @returns
+ * JSON-able structure which can be further processed with, say,
+ * {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify|JSON.stringify})
+ */
+export function toJsonable(that: OurTypes.Class): JsonObject {
+  return serializeClass(that);
+}
+
+// endregion
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/stringification.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/stringification.ts
new file mode 100644
index 000000000..9af7bc1a4
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/stringification.ts
@@ -0,0 +1,88 @@
+/**
+ * De/serialize enumerations from and to string representations.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "./types";
+
+const MODEL_TYPE_FROM_STRING = new Map<string, OurTypes.ModelType>([
+  [
+    "SomeItem",
+    OurTypes.ModelType.SomeItem
+  ],
+  [
+    "SpecialItem",
+    OurTypes.ModelType.SpecialItem
+  ],
+  [
+    "Container",
+    OurTypes.ModelType.Container
+  ],
+  [
+    "Wrapper",
+    OurTypes.ModelType.Wrapper
+  ]
+]);
+
+/**
+ * Parse `text` as a string representation of {@link types!ModelType}.
+ *
+ * @param text - string representation of {@link types!ModelType}
+ * @returns literal of {@link types!ModelType}, if valid, and `null` otherwise
+ */
+export function modelTypeFromString(
+  text: string
+): OurTypes.ModelType | null {
+  const result = MODEL_TYPE_FROM_STRING.get(text);
+  return result !== undefined ? result : null;
+}
+
+// NOTE (mristin):
+// The literals of ModelType are consecutive integers starting at 0,
+// so we index into an array instead of looking the text up in a map.
+const MODEL_TYPE_TO_STRING: readonly string[] = [
+  "SomeItem",
+  "SpecialItem",
+  "Container",
+  "Wrapper"
+];
+
+/**
+ * Translate {@link types!ModelType} to a string.
+ *
+ * @param value - to be stringified
+ * @returns string representation of {@link types!ModelType},
+ * if `value` valid, and `null` otherwise
+ */
+export function modelTypeToString(
+  value: OurTypes.ModelType
+): string | null {
+  const result = MODEL_TYPE_TO_STRING[value];
+  return result !== undefined ? result : null;
+}
+
+/**
+ * Translate {@link types!ModelType} to a string.
+ *
+ * @param value - to be stringified
+ * @returns string representation of {@link types!ModelType}
+ * @throws
+ * {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error|Error}
+ * if the `value` is invalid
+ */
+export function mustModelTypeToString(
+  value: OurTypes.ModelType
+): string {
+  const result = MODEL_TYPE_TO_STRING[value];
+  if (result === undefined) {
+    throw new Error(
+      `Invalid literal of ModelType: ${value}`
+    );
+  }
+  return result;
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/types.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/types.ts
new file mode 100644
index 000000000..35f0b6869
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/types.ts
@@ -0,0 +1,1448 @@
+/**
+ * Test the variance of the containers passed as arguments.
+ *
+ * @remarks
+ * A read-only `Sequence[...]` argument of a verification function is generic if its
+ * items are instances of a class with descendants, so that the sequences of
+ * the descendants can be passed to it without a copy. The arguments of the methods
+ * and the mutable `List[...]` arguments remain invariant.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+/**
+ * Represent runtime model type of an instance.
+ */
+export enum ModelType {
+  SomeItem = 0,
+  SpecialItem = 1,
+  Container = 2,
+  Wrapper = 3
+}
+
+/**
+ * Iterate over the literals of {@link ModelType}.
+ *
+ * @remark
+ * TypeScript does not provide an elegant way to iterate over the literals, so
+ * this function helps you avoid common errors and pitfalls.
+ *
+ * @return iterator over the literals
+ */
+export function *overModelType (
+): Iterable<ModelType> {
+  // NOTE (mristin):
+  // We yield numbers instead of literals to avoid name lookups on platforms
+  // which do not provide JIT compilation of hot paths.
+  yield <ModelType>0;  // SomeItem
+  yield <ModelType>1;  // SpecialItem
+  yield <ModelType>2;  // Container
+  yield <ModelType>3;  // Wrapper
+}
+
+/**
+ * Represent the most general class of the meta-model.
+ */
+export abstract class Class {
+  /**
+   * Indicate the runtime model type of an instance.
+   */
+  abstract modelType(): ModelType;
+
+  /**
+   * Iterate over all the instances referenced from this one.
+   */
+  abstract descendOnce(): IterableIterator<Class>;
+
+  /**
+   * Iterate recursively over all the instances referenced from this one.
+   */
+  abstract descend(): IterableIterator<Class>;
+
+  /**
+   * Dispatch the `visitor` on this instance.
+   *
+   * @param visitor - to be dispatched
+   */
+  abstract accept(visitor: AbstractVisitor): void;
+
+  /**
+   * Dispatch the `visitor` on this instance with `context`.
+   *
+   * @param visitor - to be dispatched
+   * @param context - of the visitation
+   * @typeParam ContextT - type of the visitation context
+   */
+  abstract acceptWithContext<ContextT>(
+    visitor: AbstractVisitorWithContext<ContextT>,
+    context: ContextT
+  ): void;
+
+  /**
+   * Dispatch the `transformer` on this instance.
+   *
+   * @param transformer - to be dispatched
+   * @return this instance transformed
+   * @typeParam T - type of the transformation result
+   */
+  abstract transform<T>(transformer: AbstractTransformer<T>): T;
+
+  /**
+   * Dispatch the `transformer` on this instance in `context`.
+   *
+   * @param transformer - to be dispatched
+   * @param context - of the transformation
+   * @return this instance transformed
+   * @typeParam T - type of the transformation result
+   */
+  abstract transformWithContext<ContextT, T>(
+    transformer: AbstractTransformerWithContext<ContextT, T>,
+    context: ContextT
+  ): T;
+}
+
+export interface IItem extends Class {
+  name: string;
+
+  nickname: string | null;
+}
+
+// eslint-disable-next-line @typescript-eslint/no-empty-interface
+export interface ISomeItem
+  extends IItem {
+  // Intentionally empty.
+}
+
+export class SomeItem
+  extends Class
+  implements ISomeItem {
+  /**
+   * Indicate the runtime model type of the instance.
+   */
+  modelType(): ModelType {
+    // NOTE (mristin):
+    // We yield numbers instead of literals to avoid name lookups on platforms
+    // which do not provide JIT compilation of hot paths.
+    return <ModelType>0;  // SomeItem
+  }
+
+  name: string;
+
+  nickname: string | null;
+
+  /**
+   * Iterate over the instances referenced from this instance.
+   *
+   * We do not recurse into the referenced instances.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descendOnce(): IterableIterator<Class> {
+    // No descendable properties
+  }
+
+  /**
+   * Iterate recursively over the instances referenced from this instance.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descend(): IterableIterator<Class> {
+    // No descendable properties
+  }
+
+  /**
+   * Dispatch `visitor` on this instance.
+   *
+   * @param visitor - to visit this instance
+   */
+  accept(visitor: AbstractVisitor): void {
+    visitor.visitSomeItem(this);
+  }
+
+  /**
+   * Dispatch `visitor` with `context` on this instance.
+   *
+   * @param visitor - to visit this instance
+   * @param context - to be passed along to the dispatched visitor method
+   * @typeParam ContextT - type of the context
+   */
+  acceptWithContext<ContextT>(
+    visitor: AbstractVisitorWithContext<ContextT>,
+    context: ContextT
+  ) {
+    visitor.visitSomeItemWithContext(this, context);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance.
+   *
+   * @param transformer - to transform this instance
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   */
+  transform<T>(transformer: AbstractTransformer<T>): T {
+    return transformer.transformSomeItem(this);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance in `context`.
+   *
+   * @param transformer - to transform this instance
+   * @param context - to be passed along to the `transformer`
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   * @paramType ContextT - type of the transformation context
+   */
+  transformWithContext<ContextT, T>(
+    transformer: AbstractTransformerWithContext<ContextT, T>,
+    context: ContextT
+  ): T {
+    return transformer.transformSomeItemWithContext(
+      this, context
+    );
+  }
+
+  constructor(
+    name: string,
+    nickname: string | null = null
+  ) {
+    super();
+    this.name = name;
+    this.nickname = nickname;
+  }
+}
+
+export class SpecialItem
+  extends Class
+  implements ISomeItem {
+  /**
+   * Indicate the runtime model type of the instance.
+   */
+  modelType(): ModelType {
+    // NOTE (mristin):
+    // We yield numbers instead of literals to avoid name lookups on platforms
+    // which do not provide JIT compilation of hot paths.
+    return <ModelType>1;  // SpecialItem
+  }
+
+  name: string;
+
+  nickname: string | null;
+
+  level: number;
+
+  /**
+   * Iterate over the instances referenced from this instance.
+   *
+   * We do not recurse into the referenced instances.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descendOnce(): IterableIterator<Class> {
+    // No descendable properties
+  }
+
+  /**
+   * Iterate recursively over the instances referenced from this instance.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descend(): IterableIterator<Class> {
+    // No descendable properties
+  }
+
+  /**
+   * Dispatch `visitor` on this instance.
+   *
+   * @param visitor - to visit this instance
+   */
+  accept(visitor: AbstractVisitor): void {
+    visitor.visitSpecialItem(this);
+  }
+
+  /**
+   * Dispatch `visitor` with `context` on this instance.
+   *
+   * @param visitor - to visit this instance
+   * @param context - to be passed along to the dispatched visitor method
+   * @typeParam ContextT - type of the context
+   */
+  acceptWithContext<ContextT>(
+    visitor: AbstractVisitorWithContext<ContextT>,
+    context: ContextT
+  ) {
+    visitor.visitSpecialItemWithContext(this, context);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance.
+   *
+   * @param transformer - to transform this instance
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   */
+  transform<T>(transformer: AbstractTransformer<T>): T {
+    return transformer.transformSpecialItem(this);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance in `context`.
+   *
+   * @param transformer - to transform this instance
+   * @param context - to be passed along to the `transformer`
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   * @paramType ContextT - type of the transformation context
+   */
+  transformWithContext<ContextT, T>(
+    transformer: AbstractTransformerWithContext<ContextT, T>,
+    context: ContextT
+  ): T {
+    return transformer.transformSpecialItemWithContext(
+      this, context
+    );
+  }
+
+  constructor(
+    name: string,
+    level: number,
+    nickname: string | null = null
+  ) {
+    super();
+    this.name = name;
+    this.nickname = nickname;
+    this.level = level;
+  }
+}
+
+export class Container extends Class {
+  /**
+   * Indicate the runtime model type of the instance.
+   */
+  modelType(): ModelType {
+    // NOTE (mristin):
+    // We yield numbers instead of literals to avoid name lookups on platforms
+    // which do not provide JIT compilation of hot paths.
+    return <ModelType>2;  // Container
+  }
+
+  items: Array<IItem>;
+
+  someItems: Array<SomeItem>;
+
+  specialItems: Array<SpecialItem> | null;
+
+  /**
+   * Yield from {@link specialItems} if it is set, or yield nothing.
+   */
+  *overSpecialItemsOrEmpty(): IterableIterator<SpecialItem> {
+    if (this.specialItems !== null) {
+      yield * this.specialItems;
+    }
+    return;
+  }
+
+  /**
+   * Count the `items`.
+   *
+   * @remarks
+   *
+   * The arguments of the methods are never generic, so only the sequences of
+   * {@link IItem} can be passed to it, but not the sequences of
+   * the descendants.
+   */
+  countItems(
+    items: Array<IItem>
+  ): number {
+    return items.length;
+  }
+
+  /**
+   * Iterate over the instances referenced from this instance.
+   *
+   * We do not recurse into the referenced instances.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descendOnce(): IterableIterator<Class> {
+    yield * descend_Container(this, false);
+  }
+
+  /**
+   * Iterate recursively over the instances referenced from this instance.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descend(): IterableIterator<Class> {
+    yield * descend_Container(this, true);
+  }
+
+  /**
+   * Dispatch `visitor` on this instance.
+   *
+   * @param visitor - to visit this instance
+   */
+  accept(visitor: AbstractVisitor): void {
+    visitor.visitContainer(this);
+  }
+
+  /**
+   * Dispatch `visitor` with `context` on this instance.
+   *
+   * @param visitor - to visit this instance
+   * @param context - to be passed along to the dispatched visitor method
+   * @typeParam ContextT - type of the context
+   */
+  acceptWithContext<ContextT>(
+    visitor: AbstractVisitorWithContext<ContextT>,
+    context: ContextT
+  ) {
+    visitor.visitContainerWithContext(this, context);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance.
+   *
+   * @param transformer - to transform this instance
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   */
+  transform<T>(transformer: AbstractTransformer<T>): T {
+    return transformer.transformContainer(this);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance in `context`.
+   *
+   * @param transformer - to transform this instance
+   * @param context - to be passed along to the `transformer`
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   * @paramType ContextT - type of the transformation context
+   */
+  transformWithContext<ContextT, T>(
+    transformer: AbstractTransformerWithContext<ContextT, T>,
+    context: ContextT
+  ): T {
+    return transformer.transformContainerWithContext(
+      this, context
+    );
+  }
+
+  constructor(
+    items: Array<IItem>,
+    someItems: Array<SomeItem>,
+    specialItems: Array<SpecialItem> | null = null
+  ) {
+    super();
+    this.items = items;
+    this.someItems = someItems;
+    this.specialItems = specialItems;
+  }
+}
+
+/**
+ * Iterate over the instances referenced from `that`, and recursively
+ * over their descendants if `recurse` is set.
+ */
+function *descend_Container(
+  that: Container,
+  recurse: boolean
+): IterableIterator<Class> {
+  yield * descend_ListOf_IItem(that.items, recurse);
+
+  yield * descend_ListOf_SomeItem(that.someItems, recurse);
+
+  if (that.specialItems !== null) {
+    yield * descend_ListOf_SpecialItem(that.specialItems, recurse);
+  }
+}
+
+export class Wrapper extends Class {
+  /**
+   * Indicate the runtime model type of the instance.
+   */
+  modelType(): ModelType {
+    // NOTE (mristin):
+    // We yield numbers instead of literals to avoid name lookups on platforms
+    // which do not provide JIT compilation of hot paths.
+    return <ModelType>3;  // Wrapper
+  }
+
+  container: Container;
+
+  /**
+   * Iterate over the instances referenced from this instance.
+   *
+   * We do not recurse into the referenced instances.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descendOnce(): IterableIterator<Class> {
+    yield * descend_Wrapper(this, false);
+  }
+
+  /**
+   * Iterate recursively over the instances referenced from this instance.
+   *
+   * @returns Iterator over the referenced instances
+   */
+  *descend(): IterableIterator<Class> {
+    yield * descend_Wrapper(this, true);
+  }
+
+  /**
+   * Dispatch `visitor` on this instance.
+   *
+   * @param visitor - to visit this instance
+   */
+  accept(visitor: AbstractVisitor): void {
+    visitor.visitWrapper(this);
+  }
+
+  /**
+   * Dispatch `visitor` with `context` on this instance.
+   *
+   * @param visitor - to visit this instance
+   * @param context - to be passed along to the dispatched visitor method
+   * @typeParam ContextT - type of the context
+   */
+  acceptWithContext<ContextT>(
+    visitor: AbstractVisitorWithContext<ContextT>,
+    context: ContextT
+  ) {
+    visitor.visitWrapperWithContext(this, context);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance.
+   *
+   * @param transformer - to transform this instance
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   */
+  transform<T>(transformer: AbstractTransformer<T>): T {
+    return transformer.transformWrapper(this);
+  }
+
+  /**
+   * Dispatch the `transformer` on this instance in `context`.
+   *
+   * @param transformer - to transform this instance
+   * @param context - to be passed along to the `transformer`
+   * @returns transformation of this instance
+   * @paramType T - type of the transformation result
+   * @paramType ContextT - type of the transformation context
+   */
+  transformWithContext<ContextT, T>(
+    transformer: AbstractTransformerWithContext<ContextT, T>,
+    context: ContextT
+  ): T {
+    return transformer.transformWrapperWithContext(
+      this, context
+    );
+  }
+
+  constructor(container: Container) {
+    super();
+    this.container = container;
+  }
+}
+
+/**
+ * Iterate over the instances referenced from `that`, and recursively
+ * over their descendants if `recurse` is set.
+ */
+function *descend_Wrapper(
+  that: Wrapper,
+  recurse: boolean
+): IterableIterator<Class> {
+  yield that.container;
+
+  if (recurse) {
+    yield * that.container.descend();
+  }
+}
+
+/**
+ * Iterate over the class instances held by `that`.
+ *
+ * If `recurse` is set, descend recursively into the instances as well.
+ */
+function *descend_ListOf_IItem(
+  that: Array<IItem>,
+  recurse: boolean
+): IterableIterator<Class> {
+  if (!recurse) {
+    yield * that;
+    return;
+  }
+
+  for (const item of that) {
+    yield item;
+
+    yield * item.descend();
+  }
+}
+
+/**
+ * Iterate over the class instances held by `that`.
+ *
+ * If `recurse` is set, descend recursively into the instances as well.
+ */
+function *descend_ListOf_SomeItem(
+  that: Array<SomeItem>,
+  recurse: boolean
+): IterableIterator<Class> {
+  if (!recurse) {
+    yield * that;
+    return;
+  }
+
+  for (const item of that) {
+    yield item;
+
+    yield * item.descend();
+  }
+}
+
+/**
+ * Iterate over the class instances held by `that`.
+ *
+ * If `recurse` is set, descend recursively into the instances as well.
+ */
+function *descend_ListOf_SpecialItem(
+  that: Array<SpecialItem>,
+  recurse: boolean
+): IterableIterator<Class> {
+  if (!recurse) {
+    yield * that;
+    return;
+  }
+
+  for (const item of that) {
+    yield item;
+
+    yield * item.descend();
+  }
+}
+
+/**
+ * Visit the instances of the model.
+ */
+export abstract class AbstractVisitor {
+  /**
+   * Double-dispatch on `that`.
+   */
+  visit(that: Class): void {
+    that.accept(this);
+  }
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  abstract visitSomeItem(
+    that: SomeItem
+  ): void;
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  abstract visitSpecialItem(
+    that: SpecialItem
+  ): void;
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  abstract visitContainer(
+    that: Container
+  ): void;
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  abstract visitWrapper(
+    that: Wrapper
+  ): void;
+}
+
+/**
+ * Visit the instances of the model with context.
+ *
+ * @typeParam ContextT - type of the visitation context
+ */
+export abstract class AbstractVisitorWithContext<ContextT> {
+  /**
+   * Double-dispatch on `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  visitWithContext(
+    that: Class,
+    context: ContextT
+  ): void {
+    that.acceptWithContext(this, context);
+  }
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  abstract visitSomeItemWithContext(
+    that: SomeItem,
+    context: ContextT
+  ): void;
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  abstract visitSpecialItemWithContext(
+    that: SpecialItem,
+    context: ContextT
+  ): void;
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  abstract visitContainerWithContext(
+    that: Container,
+    context: ContextT
+  ): void;
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  abstract visitWrapperWithContext(
+    that: Wrapper,
+    context: ContextT
+  ): void;
+}
+
+/**
+ * Visit the instances of the model without action.
+ *
+ * @remarks
+ * This visitor is not meant to be directly used. Instead, you usually
+ * inherit from it, and implement only the relevant visit methods.
+ */
+export class PassThroughVisitor extends AbstractVisitor {
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  visitSomeItem(
+    that: SomeItem
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visit(another);
+    }
+  }
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  visitSpecialItem(
+    that: SpecialItem
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visit(another);
+    }
+  }
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  visitContainer(
+    that: Container
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visit(another);
+    }
+  }
+
+  /**
+   * Visit `that`.
+   *
+   * @param that - instance to be visited
+   */
+  visitWrapper(
+    that: Wrapper
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visit(another);
+    }
+  }
+}
+
+/**
+ * Visit the instances of the model without action and in context.
+ *
+ * @remarks
+ * This visitor is not meant to be directly used. Instead, you usually
+ * inherit from it, and implement only the relevant visit methods.
+ */
+export class PassThroughVisitorWithContext<ContextT>
+    extends AbstractVisitorWithContext<ContextT> {
+  /**
+   * Double-dispatch on `that` in `context`.
+   */
+  visitWithContext(
+    that: Class,
+    context: ContextT
+  ): void {
+    that.acceptWithContext(this, context);
+  }
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  visitSomeItemWithContext(
+    that: SomeItem,
+    context: ContextT
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visitWithContext(another, context);
+    }
+  }
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  visitSpecialItemWithContext(
+    that: SpecialItem,
+    context: ContextT
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visitWithContext(another, context);
+    }
+  }
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  visitContainerWithContext(
+    that: Container,
+    context: ContextT
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visitWithContext(another, context);
+    }
+  }
+
+  /**
+   * Visit `that` in `context`.
+   *
+   * @param that - instance to be visited
+   * @param context - of the visitation
+   */
+  visitWrapperWithContext(
+    that: Wrapper,
+    context: ContextT
+  ): void {
+    for (const another of that.descendOnce()) {
+      this.visitWithContext(another, context);
+    }
+  }
+}
+
+/**
+ * Transform the instance of the model.
+ *
+ * @typeParam T - type of the transformation result
+ */
+export abstract class AbstractTransformer<T> {
+  /**
+   * Double-dispatch on `that`.
+   */
+  transform(that: Class): T {
+    return that.transform(this);
+  }
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  abstract transformSomeItem(
+    that: SomeItem
+  ): T;
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  abstract transformSpecialItem(
+    that: SpecialItem
+  ): T;
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  abstract transformContainer(
+    that: Container
+  ): T;
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  abstract transformWrapper(
+    that: Wrapper
+  ): T;
+}
+
+/**
+ * Transform the instances of the model in context.
+ *
+ * @typeParam ContextT - type of the transformation context
+ * @typeParam T - type of the transformation result
+ */
+export abstract class AbstractTransformerWithContext<ContextT, T> {
+  /**
+   * Double-dispatch on `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the transformation
+   * @returns transformed `that`
+   */
+  transformWithContext(
+    that: Class,
+    context: ContextT
+  ): T {
+    return that.transformWithContext(this, context);
+  }
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the transformation
+   * @returns transformed `that`
+   */
+  abstract transformSomeItemWithContext(
+    that: SomeItem,
+    context: ContextT
+  ): T;
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the transformation
+   * @returns transformed `that`
+   */
+  abstract transformSpecialItemWithContext(
+    that: SpecialItem,
+    context: ContextT
+  ): T;
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the transformation
+   * @returns transformed `that`
+   */
+  abstract transformContainerWithContext(
+    that: Container,
+    context: ContextT
+  ): T;
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the transformation
+   * @returns transformed `that`
+   */
+  abstract transformWrapperWithContext(
+    that: Wrapper,
+    context: ContextT
+  ): T;
+}
+
+/**
+ * Transform the instances of the model.
+ *
+ * @remarks
+ * If you do not override the transformation methods, they simply
+ * return {@link defaultResult}.
+ *
+ * @typeParam T - type of the transformation result
+ */
+export class TransformerWithDefault<T> extends AbstractTransformer<T> {
+  /**
+   * Default value which is returned if no override of the transformation
+   */
+  defaultResult: T
+
+  /**
+   * Initialize with the given `default` value.
+   *
+   * @param defaultResult - returned if no override of the transformation
+   */
+  constructor(defaultResult: T) {
+    super();
+    this.defaultResult = defaultResult;
+  }
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSomeItem(
+    that: SomeItem
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSpecialItem(
+    that: SpecialItem
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformContainer(
+    that: Container
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that`.
+   *
+   * @param that - instance to be transformed
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformWrapper(
+    that: Wrapper
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+}
+
+/**
+ * Transform the instances of the model in context.
+ *
+ * @remarks
+ * If you do not override the transformation methods, they simply
+ * return {@link defaultResult}.
+ *
+ * @typeParam ContextT - type of the visitation context
+ * @typeParam T - type of the transformation result
+ */
+export class TransformerWithDefaultAndContext<ContextT, T>
+    extends AbstractTransformerWithContext<ContextT, T> {
+  /**
+   * Default value which is returned if no override of the transformation
+   */
+  defaultResult: T
+
+  /**
+   * Initialize with the given `default` value.
+   *
+   * @param defaultResult - returned if no override of the transformation
+   */
+  constructor(defaultResult: T) {
+    super();
+    this.defaultResult = defaultResult;
+  }
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the visitation
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSomeItemWithContext(
+    that: SomeItem,
+    context: ContextT
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the visitation
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSpecialItemWithContext(
+    that: SpecialItem,
+    context: ContextT
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the visitation
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformContainerWithContext(
+    that: Container,
+    context: ContextT
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /**
+   * Transform `that` in `context`.
+   *
+   * @param that - instance to be transformed
+   * @param context - of the visitation
+   * @returns transformed `that`
+   */
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformWrapperWithContext(
+    that: Wrapper,
+    context: ContextT
+  ): T {
+    return this.defaultResult;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+}
+
+/**
+ * Try to cast an instance of the model to {@link IItem}.
+ */
+class AsItemTransformer
+    extends AbstractTransformer<IItem | null> {
+  transformSomeItem(
+    that: SomeItem
+  ): IItem | null {
+    return that as IItem;
+  }
+
+  transformSpecialItem(
+    that: SpecialItem
+  ): IItem | null {
+    return that as IItem;
+  }
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformContainer(
+    that: Container
+  ): IItem | null {
+    return null;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformWrapper(
+    that: Wrapper
+  ): IItem | null {
+    return null;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+}
+
+const AS_ITEM_TRANSFORMER =
+  new AsItemTransformer();
+
+/**
+ * Try to cast `that` instance to
+ * the interface {@link IItem}.
+ *
+ * @param that - instance to be casted
+ * @returns - casted `that` if cast successful, or `null`
+ */
+export function asItem(
+  that: Class
+): IItem | null {
+  return AS_ITEM_TRANSFORMER.transform(that);
+}
+
+/**
+ * Check the type of `that` instance.
+ *
+ * @param that - instance to be type-checked
+ * @returns `true` if the type check is successful
+ */
+export function isItem(
+  that: Class
+): that is IItem {
+  return asItem(that) !== null;
+}
+
+/**
+ * Try to cast an instance of the model to {@link ISomeItem}.
+ */
+class AsSomeItemTransformer
+    extends AbstractTransformer<ISomeItem | null> {
+  transformSomeItem(
+    that: SomeItem
+  ): ISomeItem | null {
+    return that as ISomeItem;
+  }
+
+  transformSpecialItem(
+    that: SpecialItem
+  ): ISomeItem | null {
+    return that as ISomeItem;
+  }
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformContainer(
+    that: Container
+  ): ISomeItem | null {
+    return null;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformWrapper(
+    that: Wrapper
+  ): ISomeItem | null {
+    return null;
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+}
+
+const AS_SOME_ITEM_TRANSFORMER =
+  new AsSomeItemTransformer();
+
+/**
+ * Try to cast `that` instance to
+ * the interface {@link ISomeItem}.
+ *
+ * @param that - instance to be casted
+ * @returns - casted `that` if cast successful, or `null`
+ */
+export function asSomeItem(
+  that: Class
+): ISomeItem | null {
+  return AS_SOME_ITEM_TRANSFORMER.transform(that);
+}
+
+/**
+ * Check the type of `that` instance.
+ *
+ * @param that - instance to be type-checked
+ * @returns `true` if the type check is successful
+ */
+export function isSomeItem(
+  that: Class
+): that is ISomeItem {
+  return asSomeItem(that) !== null;
+}
+
+/**
+ * Try to cast `that` instance to
+ * the class {@link SpecialItem}.
+ *
+ * @param that - instance to be casted
+ * @returns - casted `that` if cast successful, or `null`
+ */
+export function asSpecialItem(
+  that: Class
+): SpecialItem | null {
+  return (that instanceof SpecialItem)
+    ? <SpecialItem>that
+    : null;
+}
+
+/**
+ * Check the type of `that` instance.
+ *
+ * @param that - instance to be type-checked
+ * @returns `true` if the type check is successful
+ */
+export function isSpecialItem(
+  that: Class
+): that is SpecialItem {
+  return that instanceof SpecialItem;
+}
+
+/**
+ * Try to cast `that` instance to
+ * the class {@link Container}.
+ *
+ * @param that - instance to be casted
+ * @returns - casted `that` if cast successful, or `null`
+ */
+export function asContainer(
+  that: Class
+): Container | null {
+  return (that instanceof Container)
+    ? <Container>that
+    : null;
+}
+
+/**
+ * Check the type of `that` instance.
+ *
+ * @param that - instance to be type-checked
+ * @returns `true` if the type check is successful
+ */
+export function isContainer(
+  that: Class
+): that is Container {
+  return that instanceof Container;
+}
+
+/**
+ * Try to cast `that` instance to
+ * the class {@link Wrapper}.
+ *
+ * @param that - instance to be casted
+ * @returns - casted `that` if cast successful, or `null`
+ */
+export function asWrapper(
+  that: Class
+): Wrapper | null {
+  return (that instanceof Wrapper)
+    ? <Wrapper>that
+    : null;
+}
+
+/**
+ * Check the type of `that` instance.
+ *
+ * @param that - instance to be type-checked
+ * @returns `true` if the type check is successful
+ */
+export function isWrapper(
+  that: Class
+): that is Wrapper {
+  return that instanceof Wrapper;
+}
+
+class TypeMatcher extends AbstractTransformerWithContext<
+  Readonly<Class>,
+  boolean
+> {
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSomeItemWithContext(
+    that: SomeItem,
+    other: Class
+  ): boolean {
+    return isSomeItem(other);
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformSpecialItemWithContext(
+    that: SpecialItem,
+    other: Class
+  ): boolean {
+    return isSpecialItem(other);
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformContainerWithContext(
+    that: Container,
+    other: Class
+  ): boolean {
+    return isContainer(other);
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+
+  /* eslint-disable @typescript-eslint/no-unused-vars */
+  transformWrapperWithContext(
+    that: Wrapper,
+    other: Class
+  ): boolean {
+    return isWrapper(other);
+  }
+  /* eslint-enable @typescript-eslint/no-unused-vars */
+}
+
+const TYPE_MATCHER = new TypeMatcher();
+
+/**
+ * Check whether the type of `that` matches the type of `other` instance.
+ *
+ * @remarks
+ * We check with `is*` function. Hence, if the class of `other` is a subclass of
+ * the class of `that`, we confirm the match.
+ *
+ * @param that - standard instance
+ * @param other - instance whose type is compared against `that`
+ */
+export function typesMatch<ClassT extends Class>(
+  that: ClassT,
+  other: Class
+): other is ClassT {
+  return TYPE_MATCHER.transformWithContext(that, other);
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/verification.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/verification.ts
new file mode 100644
index 000000000..307ac6527
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/verification.ts
@@ -0,0 +1,818 @@
+/**
+ * Verify that the instances of the meta-model satisfy the invariants.
+ *
+ * Here is an example how to verify an instance of {@link types.SomeItem}:
+ *
+ * ```ts
+ * import * as OurTypes from "@dummy-works/dummy/types";
+ * import * as OurVerification from "@dummy-works/dummy/verification";
+ *
+ * const anInstance = new OurTypes.SomeItem(
+ *   // ... some constructor arguments ...
+ * );
+ *
+ * for (const error of OurVerification.verify(anInstance)) {
+ *   console.log(`${error.message} at: ${error.path}`);
+ * }
+ * ```
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurCommon from "./common";
+import * as OurConstants from "./constants";
+import * as OurTypes from "./types";
+
+// The generated code might contain deliberately double negations. For example,
+// when the constraint is formulated as a NAND and we check that the constraint
+// is not fulfilled. Therefore, we disable this linting rule.
+/* eslint no-extra-boolean-cast: 0 */
+
+// NOTE (mristin):
+// The SDK defines three of these path vocabularies: this one, the one in
+// the `jsonization` module, and the one in the `xmlcommon` module. They look
+// alike, and it is tempting to merge them, but they are not interchangeable.
+//
+// Each of them points into a different thing:
+//
+// * This one points into the instances which you built, so a property segment
+//   holds a class of the meta-model.
+// * The jsonization's points into the JSON-able structure being read or
+//   written, so a property segment holds the JSON-able object instead: while
+//   a document is being parsed, the instance which the property would belong
+//   to does not exist yet.
+// * The xmlcommon's points into the XML document, where there are no
+//   properties at all, only elements, so it names an element instead. It is
+//   also the only one whose segments carry no back-pointer, as the reading is
+//   a single pass over a token stream and the element is gone by the time
+//   the error comes back out.
+//
+// The three also render differently: a path into the instances is
+// a TypeScript access expression, a path into a JSON-able structure starts at
+// the root of the document and carries no leading dot, and a path into an XML
+// document is a relative XPath.
+//
+// Merging them would mean either dropping the back-pointers, which have been
+// part of the public API of this SDK since before these modules were split
+// apart, or defining a single path over the union of all the segment kinds --
+// in which case every consumer would have to handle segments which can never
+// occur in its world. Three small vocabularies which each say exactly what
+// they can say cost less than one large one which lies about its range.
+
+/**
+ * Represent a property access on a path to an erroneous value.
+ */
+export class PropertySegment {
+  /**
+   * Instance containing the property
+   */
+  readonly instance: OurTypes.Class;
+
+  /**
+   * Name of the property
+   */
+  readonly name: string;
+
+  constructor(instance: OurTypes.Class, name: string) {
+    this.instance = instance;
+    this.name = name;
+  }
+
+  toString(): string {
+    return `.${this.name}`;
+  }
+}
+
+/**
+ * Represent an index access on a path to an erroneous value.
+ */
+export class IndexSegment {
+  /**
+   * Sequence containing the item at {@link index}
+   */
+  readonly sequence: ReadonlyArray<unknown>;
+
+  /**
+   * Index of the item in the {@link sequence}
+   */
+  readonly index: number;
+
+  constructor(sequence: ReadonlyArray<unknown>, index: number) {
+    this.sequence = sequence;
+    this.index = index;
+  }
+
+  toString(): string {
+    return `[${this.index}]`;
+  }
+}
+
+/**
+ * Represent a member access on a path to an erroneous value.
+ *
+ * @remarks
+ *
+ * Unlike a {@link PropertySegment}, which names a property of one of our
+ * classes, a key names a member of an open JSON-able object. It is known only
+ * at run time, and can be any string at all, so it is always rendered as
+ * a subscript.
+ */
+export class KeySegment {
+  /**
+   * Object containing the value at {@link key}
+   */
+  readonly object: { readonly [key: string]: unknown };
+
+  /**
+   * Key of the value in the {@link object}
+   */
+  readonly key: string;
+
+  constructor(object: { readonly [key: string]: unknown }, key: string) {
+    this.object = object;
+    this.key = key;
+  }
+
+  toString(): string {
+    return `[${JSON.stringify(this.key)}]`;
+  }
+}
+
+export type Segment = PropertySegment | IndexSegment | KeySegment;
+
+/**
+ * Represent the relative path to the erroneous value.
+ */
+export class Path {
+  readonly segments: Array<Segment> = [];
+
+  prepend(segment: Segment): void {
+    this.segments.unshift(segment);
+  }
+
+  toString(): string {
+    return this.segments.join("");
+  }
+}
+
+/**
+ * Represent a verification error in the data.
+ */
+export class VerificationError {
+  // NOTE (mristin):
+  // The name `VerificationError` is redundant since it lives in `verification` module,
+  // and it would have made more sense to call it simply `Error`. Unfortunately in this case,
+  // `Error` is a reserved name by JavaScript.
+
+  /**
+   * Human-readable description of the error
+   */
+  readonly message: string;
+
+  /**
+   * Path to the erroneous value
+   */
+  readonly path: Path = new Path();
+
+  /**
+   * Initialize with the given `message` and `path`.
+   *
+   * @remarks
+   * If no `path` is specified, initialize with an empty path.
+   */
+  constructor(message: string, path: Path | null = null) {
+    this.message = message;
+    this.path = (path !== null)
+      ? path
+      : new Path();
+  }
+}
+
+/**
+ * Check that the names of the `items` are unique.
+ *
+ * @remarks
+ *
+ * The `items` are a generic sequence, so the sequences of
+ * the descendants of {@link types!IItem} can be passed without a copy.
+ */
+export function namesAreUnique(
+  items: Array<OurTypes.IItem>
+): boolean {
+  const nameSet: Set<string> = new Set<string>();
+  for (const item of items) {
+    if (nameSet.has(item.name)) {
+      return false;
+    }
+    nameSet.add(item.name);
+  }
+  return true;
+}
+
+/**
+ * Iterate over a generic sequence in a generator.
+ */
+export function namesAreNonEmpty(
+  items: Array<OurTypes.IItem>
+): boolean {
+  return OurCommon.every(
+    OurCommon.map(
+      items,
+      item =>
+        OurCommon.lenStr(item.name) > 0
+    )
+  );
+}
+
+/**
+ * Narrow the items of a generic sequence in a generator.
+ */
+export function someSpecialItemHasLevel(
+  items: Array<OurTypes.IItem>
+): boolean {
+  return OurCommon.some(
+    OurCommon.map(
+      items,
+      item =>
+        (
+          OurTypes.isSpecialItem(item)
+          && (item as OurTypes.SpecialItem).level > 0
+        )
+    )
+  );
+}
+
+/**
+ * Index a generic sequence, and narrow the item.
+ */
+export function firstIsSpecial(
+  items: Array<OurTypes.IItem>
+): boolean {
+  if (items.length == 0) {
+    return false;
+  }
+  const first = OurCommon.at(items, 0);
+  if (OurTypes.isSpecialItem(first)) {
+    return (first as OurTypes.SpecialItem).level > 0;
+  }
+  return false;
+}
+
+/**
+ * Check that the nicknames of the `items` are unique, if specified.
+ *
+ * @remarks
+ *
+ * This mirrors the body of `ID_shorts_are_unique` in aas-core-meta V3.2:
+ * a local variable takes an optional property of an item of a generic sequence,
+ * and the loop continues if it is None.
+ */
+export function nicknamesAreUnique(
+  items: Array<OurTypes.IItem>
+): boolean {
+  const nicknameSet: Set<string> = new Set<string>();
+  for (const item of items) {
+    const nickname = item.nickname;
+    if (nickname === null) {
+      continue;
+    }
+    if (nicknameSet.has(nickname)) {
+      return false;
+    }
+    nicknameSet.add(nickname);
+  }
+  return true;
+}
+
+/**
+ * Narrow the loop variable over a generic sequence in a for-loop.
+ *
+ * @remarks
+ *
+ * The loop variable is of the type parameter in Go, so the down-cast needs to
+ * go through `any(...)`, and of the template parameter in C++.
+ */
+export function levelsOfSpecialItemsArePositive(
+  items: Array<OurTypes.IItem>
+): boolean {
+  for (const item of items) {
+    if (OurTypes.isSpecialItem(item)) {
+      if ((item as OurTypes.SpecialItem).level <= 0) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+/**
+ * Narrow an immutable local variable which holds an item of a generic sequence.
+ *
+ * @remarks
+ *
+ * In contrast to {@link firstIsSpecial}, the local variable is annotated, so
+ * it is of the parent class instead of the type parameter. Hence, Go down-casts
+ * it without `any(...)`, and C++ binds the item to a constant reference to
+ * the shared pointer of the parent class.
+ */
+export function lastIsSpecial(
+  items: Array<OurTypes.IItem>
+): boolean {
+  if (items.length == 0) {
+    return false;
+  }
+  const last: OurTypes.IItem = OurCommon.at(
+    items,
+    items.length - 1
+  );
+  if (OurTypes.isSpecialItem(last)) {
+    return (last as OurTypes.SpecialItem).level > 0;
+  }
+  return false;
+}
+
+/**
+ * Mix two generic sequences with an argument which is not generic.
+ *
+ * @remarks
+ *
+ * The names must differ, except for the `sharedName`, which may repeat.
+ *
+ * Go declares two type parameters, and C++ two template parameters. The nested
+ * generators iterate over two different generic sequences, so their variables
+ * are of two different type parameters.
+ */
+export function namesAreDisjoint(
+  items: Array<OurTypes.IItem>,
+  otherItems: Array<OurTypes.SomeItem>,
+  sharedName: string
+): boolean {
+  return OurCommon.every(
+    OurCommon.map(
+      items,
+      item =>
+        OurCommon.every(
+          OurCommon.map(
+            otherItems,
+            otherItem =>
+              (
+                item.name != otherItem.name
+                || item.name == sharedName
+              )
+          )
+        )
+    )
+  );
+}
+
+/**
+ * Use the immutable aliases of the generic sequences.
+ *
+ * @remarks
+ *
+ * An immutable alias of the very same type shares the type annotation of
+ * the aliased generic sequence, so it is a generic sequence itself. Go declares
+ * the alias with the type parameter, C++ with the template parameter, while C#
+ * and Java infer its type with `var`. The `alias_of_alias` aliases an alias,
+ * and the `optional_alias` aliases an optional generic sequence.
+ */
+export function aliasedNamesAreUnique(
+  items: Array<OurTypes.IItem>,
+  optionalItems: Array<OurTypes.IItem> | null
+): boolean {
+  const alias: Array<OurTypes.IItem> = items;
+  const aliasOfAlias: Array<OurTypes.IItem> = alias;
+  const optionalAlias: Array<OurTypes.IItem> | null = optionalItems;
+  for (const item of alias) {
+    if (OurTypes.isSpecialItem(item)) {
+      if ((item as OurTypes.SpecialItem).level <= 0) {
+        return false;
+      }
+    }
+  }
+  return (
+    (
+      OurCommon.every(
+        OurCommon.map(
+          aliasOfAlias,
+          item =>
+            OurCommon.lenStr(item.name) > 0
+        )
+      )
+    )
+    && namesAreUnique(aliasOfAlias)
+    && optionalNamesAreUnique(optionalAlias)
+    && (
+      (
+        (optionalAlias === null)
+        || namesAreUnique(optionalAlias)
+      )
+    )
+  );
+}
+
+/**
+ * Look up an instance of a descendant in a generic sequence.
+ *
+ * @remarks
+ *
+ * Go compares the instances as `any`'s, as the items are of the type parameter,
+ * and C++ converts the member to the shared pointer of {@link types!IItem} so that
+ * the raw pointers are comparable for any template parameter.
+ */
+export function containsSomeItem(
+  someItem: OurTypes.SomeItem,
+  items: Array<OurTypes.IItem>
+): boolean {
+  return items.includes(someItem);
+}
+
+/**
+ * Look up the items of a generic sequence in another generic sequence.
+ *
+ * @remarks
+ *
+ * The member and the items are of two different type parameters.
+ */
+export function itemsOverlap(
+  items: Array<OurTypes.IItem>,
+  otherItems: Array<OurTypes.SomeItem>
+): boolean {
+  return OurCommon.some(
+    OurCommon.map(
+      otherItems,
+      otherItem =>
+        items.includes(otherItem)
+    )
+  );
+}
+
+/**
+ * Look up an instance in a sequence which is not generic.
+ *
+ * @remarks
+ *
+ * The {@link types!SpecialItem} has no descendants, so the `items` are not
+ * a generic sequence, but Go still compares the instances as `any`'s.
+ */
+export function containsSpecialItem(
+  specialItem: OurTypes.SpecialItem,
+  items: Array<OurTypes.SpecialItem>
+): boolean {
+  return items.includes(specialItem);
+}
+
+/**
+ * Pass the local variables on to generic sequences.
+ *
+ * @remarks
+ *
+ * The `some_items` is a read-only alias without an annotation, while
+ * the `all_some_items` is an immutable local variable declared with
+ * `Final[...]`. Both hold the sequences of {@link types!ISomeItem}, and are passed
+ * on to the generic sequences of {@link types!IItem}, required as well as optional.
+ */
+export function containerNamesAreUnique(
+  container: OurTypes.Container
+): boolean {
+  const someItems = container.someItems;
+  const allSomeItems: Array<OurTypes.SomeItem> = container.someItems;
+  return (
+    namesAreUnique(someItems)
+    && namesAreUnique(allSomeItems)
+    && optionalNamesAreUnique(allSomeItems)
+  );
+}
+
+/**
+ * Pass an optional generic sequence on to a generic sequence.
+ */
+export function optionalNamesAreUnique(
+  items: Array<OurTypes.IItem> | null
+): boolean {
+  return (
+    (items === null)
+    || namesAreUnique(items)
+  );
+}
+
+/**
+ * Pass the generic sequences of the descendants on.
+ *
+ * @remarks
+ *
+ * The `someItems` are passed on as a required and as an optional
+ * sequence of the parent class, while the `specialItems` are passed on
+ * as an optional sequence and, once narrowed, as a required sequence of the parent
+ * class of the parent class.
+ */
+export function someNamesAreUnique(
+  someItems: Array<OurTypes.SomeItem>,
+  specialItems: Array<OurTypes.SpecialItem> | null
+): boolean {
+  return (
+    namesAreUnique(someItems)
+    && optionalNamesAreUnique(someItems)
+    && optionalNamesAreUnique(specialItems)
+    && optionalNamesAreUnique(null)
+    && (
+      (
+        (specialItems === null)
+        || namesAreUnique(specialItems)
+      )
+    )
+  );
+}
+
+/**
+ * Check that the levels are positive.
+ *
+ * @remarks
+ *
+ * The {@link types!SpecialItem} has no descendants, so the `items` are not
+ * a generic sequence.
+ */
+export function levelsArePositive(
+  items: Array<OurTypes.SpecialItem>
+): boolean {
+  return OurCommon.every(
+    OurCommon.map(
+      items,
+      item =>
+        item.level > 0
+    )
+  );
+}
+
+/**
+ * Verify the items of `that` recursively.
+ */
+function *verify_ListOf_class(
+  that: ReadonlyArray<OurTypes.Class>
+): IterableIterator<VerificationError> {
+  for (let i = 0; i < that.length; i++) {
+    for (const error of verify(that[i])) {
+      error.path.prepend(
+        new IndexSegment(
+          that,
+          i
+        )
+      );
+      yield error;
+    }
+  }
+}
+
+/**
+ * Verify an instance of the model recursively or non-recursively (depending on the context).
+ */
+class Verifier
+  extends OurTypes.AbstractTransformerWithContext<
+    boolean, IterableIterator<VerificationError>
+  > {
+  *transformSomeItemWithContext(
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    that: OurTypes.SomeItem,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    context: boolean
+  ): IterableIterator<VerificationError> {
+    // No verification has been defined for SomeItem.
+  }
+
+  *transformSpecialItemWithContext(
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    that: OurTypes.SpecialItem,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    context: boolean
+  ): IterableIterator<VerificationError> {
+    // No verification has been defined for SpecialItem.
+  }
+
+  *transformContainerWithContext(
+    that: OurTypes.Container,
+    context: boolean
+  ): IterableIterator<VerificationError> {
+    if (!(
+      !(that.specialItems !== null)
+      || (
+        OurCommon.every(
+          OurCommon.map(
+            that.specialItems,
+            specialItem =>
+              containsSpecialItem(specialItem, that.specialItems)
+          )
+        )
+      )
+    )) {
+      yield new VerificationError(
+        "Each special item must be among the special items."
+      )
+    }
+
+    if (!(
+      (
+        that.someItems.length == 0
+        || itemsOverlap(that.items, that.someItems)
+      )
+    )) {
+      yield new VerificationError(
+        "If there are some items, they must overlap with the items."
+      )
+    }
+
+    if (!(
+      OurCommon.every(
+        OurCommon.map(
+          that.someItems,
+          someItem =>
+            containsSomeItem(someItem, that.items)
+        )
+      )
+    )) {
+      yield new VerificationError(
+        "Some items must be among the items."
+      )
+    }
+
+    if (!(
+      aliasedNamesAreUnique(
+        that.someItems,
+        that.specialItems
+      )
+    )) {
+      yield new VerificationError(
+        "Names of some items and of special items must be unique " +
+        "through aliases."
+      )
+    }
+
+    if (!namesAreDisjoint(that.items, that.someItems, "x")) {
+      yield new VerificationError(
+        "Names of the items and of some items must be disjoint."
+      )
+    }
+
+    if (!(
+      !someSpecialItemHasLevel(that.items)
+      || lastIsSpecial(that.items)
+    )) {
+      yield new VerificationError(
+        "If there is a special item with level, the last item must " +
+        "be special."
+      )
+    }
+
+    if (!levelsOfSpecialItemsArePositive(that.items)) {
+      yield new VerificationError(
+        "Levels of the special items among the items must be " +
+        "positive."
+      )
+    }
+
+    if (!nicknamesAreUnique(that.someItems)) {
+      yield new VerificationError(
+        "Nicknames of some items must be unique."
+      )
+    }
+
+    if (!(that.countItems(that.items) == that.items.length)) {
+      yield new VerificationError(
+        "Count of the items must match the number of the items."
+      )
+    }
+
+    if (!optionalNamesAreUnique(that.specialItems)) {
+      yield new VerificationError(
+        "Names of the special items must be unique."
+      )
+    }
+
+    if (!(
+      !(that.specialItems !== null)
+      || firstIsSpecial(that.specialItems)
+    )) {
+      yield new VerificationError(
+        "The first special item must be special."
+      )
+    }
+
+    if (!(
+      !(that.specialItems !== null)
+      || levelsArePositive(that.specialItems)
+    )) {
+      yield new VerificationError(
+        "Levels of the special items must be positive."
+      )
+    }
+
+    if (!(
+      !someSpecialItemHasLevel(that.items)
+      || firstIsSpecial(that.items)
+    )) {
+      yield new VerificationError(
+        "If there is a special item with level, the first item must " +
+        "be special."
+      )
+    }
+
+    if (!namesAreNonEmpty(that.someItems)) {
+      yield new VerificationError(
+        "Names of some items must be non-empty."
+      )
+    }
+
+    if (!(
+      someNamesAreUnique(
+        that.someItems,
+        that.specialItems
+      )
+    )) {
+      yield new VerificationError(
+        "Names of some items and of special items must be unique."
+      )
+    }
+
+    if (!namesAreUnique(that.items)) {
+      yield new VerificationError(
+        "Names of the items must be unique."
+      )
+    }
+
+    if (context === true) {
+      for (const error of verify_ListOf_class(that.items)) {
+        error.path.prepend(
+          new PropertySegment(
+            that,
+            "items"
+          )
+        );
+        yield error;
+      }
+
+      for (const error of verify_ListOf_class(that.someItems)) {
+        error.path.prepend(
+          new PropertySegment(
+            that,
+            "someItems"
+          )
+        );
+        yield error;
+      }
+
+      if (that.specialItems !== null) {
+        for (const error of verify_ListOf_class(that.specialItems)) {
+          error.path.prepend(
+            new PropertySegment(
+              that,
+              "specialItems"
+            )
+          );
+          yield error;
+        }
+      }
+    }
+  }
+
+  *transformWrapperWithContext(
+    that: OurTypes.Wrapper,
+    context: boolean
+  ): IterableIterator<VerificationError> {
+    if (!containerNamesAreUnique(that.container)) {
+      yield new VerificationError(
+        "Names of some items of the container must be unique."
+      )
+    }
+
+    if (context === true) {
+      for (const error of verify(that.container)) {
+        error.path.prepend(
+          new PropertySegment(
+            that,
+            "container"
+          )
+        );
+        yield error;
+      }
+    }
+  }
+}
+
+const VERIFIER = new Verifier();
+
+/**
+ * Verify the constraints of `that`.
+ *
+ * @param that - instance to be verified
+ * @param recurse - if set, continue the verification recursively
+ * @returns a stream of verification errors
+ */
+export function *verify(
+  that: OurTypes.Class,
+  recurse = true
+): IterableIterator<VerificationError> {
+  yield * VERIFIER.transformWithContext(that, recurse);
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlcommon.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlcommon.ts
new file mode 100644
index 000000000..d9c82f917
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlcommon.ts
@@ -0,0 +1,1045 @@
+/**
+ * Provide the XML primitives shared by the modules of this SDK which read and
+ * write XML.
+ *
+ * @remarks
+ *
+ * The skipping of the ignorable tokens, the checks of the namespace and
+ * the consumption of the tags are spelled out here once, instead of once in
+ * the de/serialization of the model and once again wherever else a document is
+ * read or written.
+ *
+ * The XML namespace is a constant of this module, and not an argument which
+ * every primitive takes. Every parser wears one and the same shape,
+ * {@link ContentParser}, which is handed the cursor and nothing else, so that
+ * a parser can be given to another parser without allocating a closure; and
+ * one SDK speaks of exactly one namespace anyhow.
+ *
+ * The elements of the XML-RPC subset, over which a JSON-able value is
+ * de/serialized, are the one exception: they reside in no namespace at all,
+ * and are read with the primitives named `...InNoNamespace`.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurCommon from "./common";
+
+import {
+  CdataToken,
+  CloseTagToken,
+  CommentToken,
+  EndToken,
+  OpenTagToken,
+  ProcessingInstructionToken,
+  TextToken,
+  XmlAnyToken,
+  XmlSaxParser
+} from "xmlsax-typescript";
+
+export const NAMESPACE = "https://dummy.com";
+
+// NOTE (mristin):
+// The SDK defines three of these path vocabularies: this one, the one in
+// the `jsonization` module, and the one in the `xmlcommon` module. They look
+// alike, and it is tempting to merge them, but they are not interchangeable.
+//
+// Each of them points into a different thing:
+//
+// * This one points into the instances which you built, so a property segment
+//   holds a class of the meta-model.
+// * The jsonization's points into the JSON-able structure being read or
+//   written, so a property segment holds the JSON-able object instead: while
+//   a document is being parsed, the instance which the property would belong
+//   to does not exist yet.
+// * The xmlcommon's points into the XML document, where there are no
+//   properties at all, only elements, so it names an element instead. It is
+//   also the only one whose segments carry no back-pointer, as the reading is
+//   a single pass over a token stream and the element is gone by the time
+//   the error comes back out.
+//
+// The three also render differently: a path into the instances is
+// a TypeScript access expression, a path into a JSON-able structure starts at
+// the root of the document and carries no leading dot, and a path into an XML
+// document is a relative XPath.
+//
+// Merging them would mean either dropping the back-pointers, which have been
+// part of the public API of this SDK since before these modules were split
+// apart, or defining a single path over the union of all the segment kinds --
+// in which case every consumer would have to handle segments which can never
+// occur in its world. Three small vocabularies which each say exactly what
+// they can say cost less than one large one which lies about its range.
+
+/**
+ * Escape the characters which an XPath can not carry literally.
+ *
+ * @remarks
+ *
+ * Neither an ampersand nor a less-than sign can occur in a valid element name,
+ * but they are escaped all the same, so that a bug report over a broken
+ * document still reads.
+ */
+function escapeForXPath(text: string): string {
+  // NOTE (mristin):
+  // Mind the order -- the ampersand has to go first, or the ampersands of
+  // the replacements below would be escaped in their turn.
+  return text
+    .replace(/&/g, "&amp;")
+    .replace(/\//g, "&#47;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&apos;");
+}
+
+/**
+ * Represent an element on a path to the erroneous value.
+ */
+export class ElementSegment {
+  /**
+   * Local name of the element, without the namespace
+   */
+  readonly name: string;
+
+  constructor(name: string) {
+    this.name = name;
+  }
+
+  /**
+   * Render the segment as a tag without the namespace.
+   *
+   * @remarks
+   *
+   * We deliberately omit the namespace in the tag names. If you want to
+   * actually query with the resulting XPath, you have to insert the namespaces
+   * manually. We did not know how to include the namespace in a meaningful way,
+   * as XPath assumes namespace prefixes to be defined *outside* of the document.
+   * At least the path thus rendered is informative, and you should be able to
+   * descend it manually.
+   */
+  toString(): string {
+    return escapeForXPath(this.name);
+  }
+}
+
+/**
+ * Represent an element in a sequence on a path to the erroneous value.
+ */
+export class IndexSegment {
+  /**
+   * Index of the element in the sequence
+   */
+  readonly index: number;
+
+  constructor(index: number) {
+    this.index = index;
+  }
+
+  /**
+   * Render the segment as an element wildcard with the 1-based index of XPath.
+   */
+  toString(): string {
+    return `*[${this.index + 1}]`;
+  }
+}
+
+/**
+ * Represent a member of an open JSON-able object on a path to the erroneous
+ * element.
+ *
+ * @remarks
+ *
+ * Unlike an {@link ElementSegment}, which names an element prescribed by
+ * the meta-model, a key is known only at run time, and can be any string at
+ * all.
+ */
+export class KeySegment {
+  /**
+   * Key of the member
+   */
+  readonly key: string;
+
+  constructor(key: string) {
+    this.key = key;
+  }
+
+  /**
+   * Render the segment as a predicate on the `<name>` child element.
+   *
+   * @remarks
+   *
+   * A JSON-able object is written as an XML-RPC `<struct>`, which carries
+   * the key of a member in a `<name>` child element instead of in an attribute,
+   * so the XPath has to match on that child element.
+   */
+  toString(): string {
+    return `member[name="${escapeForXPath(this.key)}"]`;
+  }
+}
+
+export type Segment = ElementSegment | IndexSegment | KeySegment;
+
+/**
+ * Represent the relative path to the erroneous element.
+ */
+export class Path {
+  private readonly _segments = new Array<Segment>();
+
+  segments(): Array<Segment> {
+    return this._segments;
+  }
+
+  prepend(segment: Segment): void {
+    this._segments.unshift(segment);
+  }
+
+  /**
+   * Render the path as a relative XPath.
+   *
+   * @remarks
+   *
+   * We omit the leading `/` so that you can easily prefix it as you need.
+   */
+  toString(): string {
+    return this._segments.join("/");
+  }
+}
+
+/**
+ * Signal that XML de-serialization could not be performed.
+ */
+export class DeserializationError {
+  readonly message: string;
+  readonly path: Path;
+
+  constructor(message: string, path: Path | null = null) {
+    this.message = message;
+    this.path = path ?? new Path();
+  }
+}
+
+/**
+ * Signal that XML serialization could not be performed.
+ *
+ * @remarks
+ *
+ * The {@link SerializationError.path} points into the instance which was handed
+ * over for the serialization, and *not* into an XML document -- at the point of
+ * the failure there is no document yet. For example, `.submodels[0].id` tells you
+ * that the serialization broke on `that.submodels[0].id`.
+ *
+ * The path is therefore a TypeScript access expression, and not the relative
+ * XPath which the de-serialization reports, and it is a plain string, unlike
+ * the structured {@link Path} of the de-serialization: the elements which
+ * the XML representation adds on top of the instance contribute no segment, as
+ * they correspond to no property access. This concerns the element enclosing
+ * the instance itself, and the element which designates the model type of
+ * the value of a property -- a caller holding the instance reaches the value as,
+ * say, `value.idShort` and not as `value/idShort`.
+ */
+export class SerializationError extends Error {
+  private readonly _segments = new Array<string>();
+
+  /**
+   * Render the path to the erroneous value as a TypeScript access expression.
+   */
+  get path(): string {
+    return this._segments.join("");
+  }
+
+  /**
+   * Insert the access to the property `name` before the {@link path}.
+   */
+  prependProperty(name: string): void {
+    this._segments.unshift(`.${name}`);
+  }
+
+  /**
+   * Insert the access to the item at `index` before the {@link path}.
+   */
+  prependIndex(index: number): void {
+    this._segments.unshift(`[${index}]`);
+  }
+
+  /**
+   * Insert the access to the member `key` before the {@link path}.
+   *
+   * @remarks
+   *
+   * Unlike a property of one of our classes, a member of an open JSON-able
+   * object is known only at run time and can be any string at all, so it is
+   * always rendered as a subscript.
+   */
+  prependKey(key: string): void {
+    this._segments.unshift(`[${JSON.stringify(key)}]`);
+  }
+}
+
+export function newDeserializationError<T>(
+  message: string
+): OurCommon.Either<T, DeserializationError> {
+  return new OurCommon.Either<T, DeserializationError>(
+    null,
+    new DeserializationError(message)
+  );
+}
+
+/**
+ * Parse a value from `cursor`.
+ *
+ * Every parser in this module wears this one shape, which is what lets them
+ * compose: a parser can be given to another parser without a closure, since
+ * everything it needs comes from the `cursor` and from its own definition.
+ * The name says what a parser consumes -- a `parse*Content` stops right before
+ * the closing tag of the element which the caller has opened, while
+ * a `parse*Element` and a `dispatchParse*Element` read an element of their own,
+ * its tags included.
+ *
+ * @typeParam T - type of the parsed value
+ */
+export type ContentParser<T> = (
+  cursor: XmlCursor
+) => OurCommon.Either<T, DeserializationError>;
+
+export function currentTokenKind(cursor: XmlCursor): string {
+  const token = cursor.current();
+  if (token === null) {
+    return "end-of-token-stream";
+  }
+
+  return token.kind;
+}
+
+export function localNameOfTag(tag: unknown): string {
+  const aTag = tag as {
+    name?: unknown,
+    local?: unknown,
+    localName?: unknown
+  };
+
+  if (typeof aTag.local === "string") {
+    return aTag.local;
+  }
+  if (typeof aTag.localName === "string") {
+    return aTag.localName;
+  }
+  if (typeof aTag.name === "string") {
+    const colonIndex = aTag.name.indexOf(":");
+    if (colonIndex >= 0) {
+      return aTag.name.substring(colonIndex + 1);
+    }
+    return aTag.name;
+  }
+
+  return "";
+}
+
+function namespaceOfTag(tag: unknown): string {
+  const aTag = tag as { uri?: unknown, namespaceURI?: unknown };
+  if (typeof aTag.uri === "string") {
+    return aTag.uri;
+  }
+  if (typeof aTag.namespaceURI === "string") {
+    return aTag.namespaceURI;
+  }
+  return "";
+}
+
+function describeNamespace(namespace: string): string {
+  return namespace.length === 0 ? "no namespace" : `'${namespace}'`;
+}
+
+function checkExpectedOpenTagNamespace(
+  openTag: OpenTagToken,
+  expectedNamespace: string
+): DeserializationError | null {
+  const namespace = namespaceOfTag(openTag.tag);
+  if (namespace !== expectedNamespace) {
+    return new DeserializationError(
+      `Expected XML namespace ${describeNamespace(expectedNamespace)}, ` +
+        `but got ${describeNamespace(namespace)}`
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Read the next property's opening tag while parsing the sequence of
+ * properties of `className`, advancing `cursor` past it.
+ *
+ * @param cursor - to be read from
+ * @param className - name of the class being parsed, for error reporting
+ * @returns
+ * the next property's opening tag, or `null` if the closing tag of
+ * `className` was reached instead, or an error
+ */
+export function nextPropertyOpenTag(
+  cursor: XmlCursor,
+  className: string
+): OpenTagToken | DeserializationError | null {
+  const token = cursor.current();
+  if (token === null) {
+    return new DeserializationError(
+      `Unexpected end of token stream while parsing ${className}`
+    );
+  }
+
+  if (token instanceof CloseTagToken) {
+    return null;
+  }
+
+  if (!(token instanceof OpenTagToken)) {
+    return new DeserializationError(
+      "Expected an XML property start element or the closing element of " +
+      `${className}, but got token kind: ${token.kind}`
+    );
+  }
+
+  const namespaceError = checkExpectedOpenTagNamespace(token, NAMESPACE);
+  if (namespaceError !== null) {
+    return namespaceError;
+  }
+
+  cursor.advance();
+  return token;
+}
+
+function checkExpectedCloseTag(
+  closeTag: CloseTagToken,
+  expectedLocalName: string,
+  expectedNamespace: string
+): DeserializationError | null {
+  const namespace = namespaceOfTag(closeTag.tag);
+  if (namespace !== expectedNamespace) {
+    return new DeserializationError(
+      `Expected XML namespace ${describeNamespace(expectedNamespace)}, ` +
+        `but got ${describeNamespace(namespace)}`
+    );
+  }
+
+  const observedLocalName = localNameOfTag(closeTag.tag);
+  if (observedLocalName !== expectedLocalName) {
+    return new DeserializationError(
+      `Expected closing XML element '${expectedLocalName}', ` +
+      `but got '${observedLocalName}'`
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Read the next token from `cursor`, expecting it to be the closing XML
+ * element named `expectedLocalName`, and consume it.
+ */
+export function consumeCloseTag(
+  cursor: XmlCursor,
+  expectedLocalName: string
+): DeserializationError | null {
+  return consumeCloseTagInNamespace(cursor, expectedLocalName, NAMESPACE);
+}
+
+function consumeCloseTagInNamespace(
+  cursor: XmlCursor,
+  expectedLocalName: string,
+  expectedNamespace: string
+): DeserializationError | null {
+  const closeTag = cursor.current();
+  if (!(closeTag instanceof CloseTagToken)) {
+    return new DeserializationError(
+      `Expected a closing element '${expectedLocalName}', ` +
+      `but got token kind: ${currentTokenKind(cursor)}`
+    );
+  }
+
+  const closeError = checkExpectedCloseTag(
+    closeTag, expectedLocalName, expectedNamespace
+  );
+  if (closeError !== null) {
+    return closeError;
+  }
+
+  cursor.advance();
+  return null;
+}
+
+/**
+ * Read the next non-ignorable token from `cursor`, expecting it to be
+ * an opening XML element in the expected namespace.
+ *
+ * This is shared by the parsing of a single list item, a single tuple
+ * item, and the dispatch-parsing of an interface.
+ *
+ * @param cursor - to read from
+ * @returns the opening tag, or an error
+ */
+export function readNextOpenTag(
+  cursor: XmlCursor
+): OurCommon.Either<OpenTagToken, DeserializationError> {
+  return readNextOpenTagInNamespace(cursor, NAMESPACE);
+}
+
+function readNextOpenTagInNamespace(
+  cursor: XmlCursor,
+  expectedNamespace: string
+): OurCommon.Either<OpenTagToken, DeserializationError> {
+  cursor.skipIgnorable();
+  const token = cursor.current();
+  if (token === null) {
+    return newDeserializationError<OpenTagToken>(
+      "Expected an XML element, but got end of token stream"
+    );
+  }
+  if (!(token instanceof OpenTagToken)) {
+    return newDeserializationError<OpenTagToken>(
+      `Expected an XML element, but got token kind: ${token.kind}`
+    );
+  }
+
+  const namespaceError = checkExpectedOpenTagNamespace(
+    token, expectedNamespace
+  );
+  if (namespaceError !== null) {
+    return new OurCommon.Either<OpenTagToken, DeserializationError>(
+      null,
+      namespaceError
+    );
+  }
+
+  return new OurCommon.Either<OpenTagToken, DeserializationError>(token, null);
+}
+
+/**
+ * Parse the content of the XML element which the caller has opened, and consume
+ * the corresponding closing element named `localName`.
+ *
+ * This is the one thing which every value of an XML element has in common,
+ * whatever it holds: the property loop of a class calls it directly, since
+ * it has already read the opening tag and switched on its local name, and
+ * `parseNamedElement` calls it after reading an opening tag of its own.
+ *
+ * A property loop assigns *both* halves of the result -- the value as well as
+ * the error -- without looking at either first. The loop returns as soon as
+ * the error is set, so the `null` value which comes with an error is never
+ * read, and the property's variable needs no guard.
+ *
+ * @param cursor - to read from
+ * @param localName - local name of the element which the caller has opened
+ * @param parseContent - parses the content of the element
+ * @returns parsed value, or an error
+ * @typeParam T - type of the parsed value
+ */
+export function parseElementContent<T>(
+  cursor: XmlCursor,
+  localName: string,
+  parseContent: ContentParser<T>
+): OurCommon.Either<T, DeserializationError> {
+  return parseElementContentInNamespace(
+    cursor, localName, parseContent, NAMESPACE
+  );
+}
+
+function parseElementContentInNamespace<T>(
+  cursor: XmlCursor,
+  localName: string,
+  parseContent: ContentParser<T>,
+  expectedNamespace: string
+): OurCommon.Either<T, DeserializationError> {
+  const parsedOrError = parseContent(cursor);
+  if (parsedOrError.error !== null) {
+    return parsedOrError;
+  }
+
+  const closeError = consumeCloseTagInNamespace(
+    cursor, localName, expectedNamespace
+  );
+  if (closeError !== null) {
+    return new OurCommon.Either<T, DeserializationError>(null, closeError);
+  }
+
+  return parsedOrError;
+}
+
+/**
+ * Read the next XML element from `cursor`, expecting it to be named
+ * `expectedLocalName`, parse its content with `parseContent` and consume
+ * the matching closing element.
+ *
+ * This is what an item of a list or of a tuple is parsed with -- a scalar item
+ * in an element tagged `"v"`, `"v1"`, `"v2"`, *etc.*, and an item whose concrete
+ * class is statically known in an element named after that class. Rejecting
+ * an unexpected element on its local name alone spares us parsing its full
+ * (possibly deeply nested) content only to discover the mismatch afterwards.
+ *
+ * @param cursor - to read from
+ * @param expectedLocalName - the expected local name of the element
+ * @param parseContent - parses the content of the element
+ * @returns parsed value, or an error
+ * @typeParam T - type of the parsed value
+ */
+export function parseNamedElement<T>(
+  cursor: XmlCursor,
+  expectedLocalName: string,
+  parseContent: ContentParser<T>
+): OurCommon.Either<T, DeserializationError> {
+  return parseNamedElementInNamespace(
+    cursor, expectedLocalName, parseContent, NAMESPACE
+  );
+}
+
+function parseNamedElementInNamespace<T>(
+  cursor: XmlCursor,
+  expectedLocalName: string,
+  parseContent: ContentParser<T>,
+  expectedNamespace: string
+): OurCommon.Either<T, DeserializationError> {
+  const startTagOrError = readNextOpenTagInNamespace(
+    cursor, expectedNamespace
+  );
+  if (startTagOrError.error !== null) {
+    return new OurCommon.Either<T, DeserializationError>(
+      null,
+      startTagOrError.error
+    );
+  }
+  const startTag = startTagOrError.mustValue();
+
+  const observedLocalName = localNameOfTag(startTag.tag);
+  if (observedLocalName !== expectedLocalName) {
+    return newDeserializationError<T>(
+      `Expected the element '${expectedLocalName}', ` +
+        `but got '${observedLocalName}'`
+    );
+  }
+
+  cursor.advance();
+
+  return parseElementContentInNamespace(
+    cursor, expectedLocalName, parseContent, expectedNamespace
+  );
+}
+
+/**
+ * Parse a sequence of list items from `cursor`, stopping (without consuming)
+ * at the first closing element.
+ *
+ * The caller is expected to read and verify the property's own closing
+ * element afterwards.
+ *
+ * @param cursor - to read from
+ * @param parseItem - parses a single list item
+ * @returns the parsed items, or an error
+ * @typeParam T - type of a single list item
+ */
+export function parseList<T>(
+  cursor: XmlCursor,
+  parseItem: ContentParser<T>
+): OurCommon.Either<Array<T>, DeserializationError> {
+  const items = new Array<T>();
+  let itemIndex = 0;
+
+  cursor.skipIgnorable();
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const maybeClose = cursor.current();
+    if (maybeClose === null) {
+      return newDeserializationError<Array<T>>(
+        "Expected an XML element corresponding to a list item " +
+          "or property closing element, but got end of token stream"
+      );
+    }
+
+    if (maybeClose instanceof CloseTagToken) {
+      break;
+    }
+
+    // NOTE (mristin):
+    // Anything but an element, *e.g.*, a text, is reported at the list itself
+    // and not at an item, as there is no item element to point to.
+    if (!(maybeClose instanceof OpenTagToken)) {
+      return newDeserializationError<Array<T>>(
+        "Expected only item elements and whitespace text, " +
+          `but got token kind: ${maybeClose.kind}`
+      );
+    }
+
+    const itemOrError = parseItem(cursor);
+    if (itemOrError.error !== null) {
+      itemOrError.error.path.prepend(new IndexSegment(itemIndex));
+      return new OurCommon.Either<Array<T>, DeserializationError>(
+        null,
+        itemOrError.error
+      );
+    }
+
+    items.push(itemOrError.mustValue());
+    itemIndex++;
+    cursor.skipIgnorable();
+  }
+
+  return new OurCommon.Either<Array<T>, DeserializationError>(items, null);
+}
+
+/**
+ * Cursor over parsed XML SAX tokens.
+ */
+export class XmlCursor {
+  private readonly _tokens: Array<XmlAnyToken>;
+  private _index = 0;
+
+  constructor(tokens: Array<XmlAnyToken>) {
+    this._tokens = tokens;
+  }
+
+  current(): XmlAnyToken | null {
+    if (this._index >= this._tokens.length) {
+      return null;
+    }
+    return this._tokens[this._index];
+  }
+
+  advance(): void {
+    if (this._index < this._tokens.length) {
+      this._index++;
+    }
+  }
+
+  skipIgnorable(): void {
+    // eslint-disable-next-line no-constant-condition
+    while (true) {
+      const token = this.current();
+      if (token === null) {
+        break;
+      }
+
+      if (token instanceof CommentToken) {
+        this.advance();
+        continue;
+      }
+
+      if (token instanceof TextToken || token instanceof CdataToken) {
+        if (token.text.trim().length === 0) {
+          this.advance();
+          continue;
+        }
+      }
+
+      break;
+    }
+  }
+}
+
+export function tokenizeXml(
+  xml: string
+): OurCommon.Either<Array<XmlAnyToken>, DeserializationError> {
+  const parser = new XmlSaxParser({ allowDoctype: false, xmlns: true });
+  const tokens = new Array<XmlAnyToken>();
+
+  try {
+    for (const token of parser.feed(xml)) {
+      tokens.push(token);
+    }
+    for (const token of parser.close()) {
+      if (!(token instanceof EndToken)) {
+        tokens.push(token);
+      }
+    }
+  } catch (error) {
+    return newDeserializationError<Array<XmlAnyToken>>(
+      `Failed to parse XML: ${error}`
+    );
+  }
+
+  return new OurCommon.Either<Array<XmlAnyToken>, DeserializationError>(
+    tokens,
+    null
+  );
+}
+
+export function readRequiredRootOpenTag(
+  cursor: XmlCursor
+): OurCommon.Either<OpenTagToken, DeserializationError> {
+  // NOTE (mristin):
+  // We skip the prolog before the root element, *i.e.*, the XML declaration,
+  // the processing instructions, the comments and the whitespace.
+  cursor.skipIgnorable();
+  while (cursor.current() instanceof ProcessingInstructionToken) {
+    cursor.advance();
+    cursor.skipIgnorable();
+  }
+
+  const token = cursor.current();
+  if (token === null) {
+    return newDeserializationError<OpenTagToken>(
+      "Expected a root XML element, but got an empty token stream"
+    );
+  }
+
+  if (!(token instanceof OpenTagToken)) {
+    return newDeserializationError<OpenTagToken>(
+      `Expected a root XML start element, but got token kind: ${token.kind}`
+    );
+  }
+
+  const namespaceError = checkExpectedOpenTagNamespace(token, NAMESPACE);
+  if (namespaceError !== null) {
+    return new OurCommon.Either<OpenTagToken, DeserializationError>(
+      null,
+      namespaceError
+    );
+  }
+
+  cursor.advance();
+
+  return new OurCommon.Either<OpenTagToken, DeserializationError>(
+    token,
+    null
+  );
+}
+
+/**
+ * Match a run of the four characters which XML calls whitespace.
+ */
+const WHITESPACE_RUN = /[ \t\n\r]+/g;
+
+/**
+ * Normalize `text` the way `whiteSpace="collapse"` prescribes.
+ *
+ * Every atomic XSD type except a string, and every type derived from one by
+ * restriction, fixes `whiteSpace` to `collapse`, and a schema author can not
+ * change it. A tab, a line feed and a carriage return each become a space,
+ * a run of spaces becomes one space, and the leading and trailing spaces go.
+ * Only the result of that is a lexical representation to be matched.
+ *
+ * Mind that this strips only the whitespace *around* the value: a space
+ * within it survives as a single space, so `2  3` becomes `2 3`, which is
+ * still no number.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#rf-whiteSpace
+ */
+export function collapseWhitespace(text: string): string {
+  return text.replace(WHITESPACE_RUN, " ").trim();
+}
+
+/**
+ * Tell whether `text` is a lexical form of `xs:base64Binary`.
+ *
+ * The whitespace is expected to be gone already. What is left has to match
+ * `(B64 B64 B64 B64)* ((B64 B64 B64 B64) | (B64 B64 B16 "=") | (B64 B04 "=="))?`
+ * -- a length which is a multiple of four, the alphabet and nothing else,
+ * an equals sign only at the very end, and, easily missed, a constrained
+ * character *before* the padding, as the bits which the padding drops have
+ * to be zero.
+ *
+ * The decoders do not agree on any of this, so every target does the same
+ * check of its own and refuses the same texts.
+ *
+ * See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+ */
+export function matchesXsBase64Binary(text: string): boolean {
+  if (text.length % 4 !== 0) {
+    return false;
+  }
+
+  if (text.length === 0) {
+    return true;
+  }
+
+  let pads = 0;
+  if (text[text.length - 1] === "=") {
+    pads = 1;
+    if (text[text.length - 2] === "=") {
+      pads = 2;
+    }
+  }
+
+  for (let i = 0; i < text.length - pads; i++) {
+    const character = text[i];
+    const inAlphabet =
+      (character >= "A" && character <= "Z") ||
+      (character >= "a" && character <= "z") ||
+      (character >= "0" && character <= "9") ||
+      character === "+" ||
+      character === "/";
+    if (!inAlphabet) {
+      return false;
+    }
+  }
+
+  // NOTE (mristin):
+  // Only these sixteen characters leave the two dropped bits at zero, and
+  // only these four leave the four dropped bits at zero.
+  if (pads === 1) {
+    return "AEIMQUYcgkosw048".includes(text[text.length - 2]);
+  }
+
+  if (pads === 2) {
+    return "AQgw".includes(text[text.length - 3]);
+  }
+
+  return true;
+}
+
+/**
+ * Drop every whitespace character of `text`.
+ *
+ * This is what `xs:base64Binary` needs: it allows whitespace between
+ * the characters and not only around them, so collapsing is not enough --
+ * the decoder accepts none of it.
+ */
+export function removeWhitespace(text: string): string {
+  return text.replace(WHITESPACE_RUN, "");
+}
+
+/**
+ * Consume the text (or CDATA) content at `cursor`, if any.
+ *
+ * The caller is responsible for reading and verifying the closing element
+ * afterwards.
+ */
+export function parseTextContent(cursor: XmlCursor): string {
+  cursor.skipIgnorable();
+
+  let text = "";
+  const maybeText = cursor.current();
+  if (maybeText instanceof TextToken || maybeText instanceof CdataToken) {
+    text = maybeText.text;
+    cursor.advance();
+    cursor.skipIgnorable();
+  }
+
+  return text;
+}
+
+/**
+ * Write the content of an XML element -- everything between its opening and its
+ * closing tag -- into `parts`.
+ *
+ * @remarks
+ *
+ * This is the one shape which every writer wears, so that a writer can be given
+ * to another writer as its item writer. The framing of the element around such
+ * a content is written by {@link writeElement}, and only there.
+ *
+ * The content is pushed as one or more separate entries instead of being
+ * concatenated as it is produced, so that the single `parts.join("")` at the very
+ * end copies every piece of text exactly once, however deeply it is nested.
+ */
+export type ContentWriter<T> = (parts: Array<string>, value: T) => void;
+
+/**
+ * Write `value` as the XML element `localName`, its content written
+ * by `writeContent`.
+ *
+ * @remarks
+ *
+ * The root element, and only the root element, declares the XML namespace. It is
+ * by definition the first element to be written, so `parts` is still empty when
+ * we push its opening tag, and we need no flag threaded through the writers to
+ * tell it apart.
+ */
+export function writeElement<T>(
+  parts: Array<string>,
+  localName: string,
+  value: T,
+  writeContent: ContentWriter<T>
+): void {
+  parts.push(
+    parts.length === 0
+      ? `<${localName} xmlns="${NAMESPACE}">`
+      : `<${localName}>`
+  );
+  writeContent(parts, value);
+  parts.push(`</${localName}>`);
+}
+
+/**
+ * Write `value`, a property of the instance being serialized, as the XML element
+ * `elementName`.
+ *
+ * @remarks
+ *
+ * This is {@link writeElement} plus the reporting: a failure anywhere beneath
+ * this property is reported at a path which begins with the property. The framing
+ * of an *item* of a list or of a tuple deliberately goes through
+ * {@link writeElement} instead, as an item is reported by its index.
+ *
+ * The path names the TypeScript property, and not the XML element: a failed
+ * serialization is reported on an *instance*, which the caller holds, and not on
+ * a document which has not been written yet. The two names part company only
+ * where the meta-model prescribes a serialization name of its own, so
+ * `propertyName` falls back to `elementName` and is spelled out at those
+ * properties alone.
+ */
+export function writeProperty<T>(
+  parts: Array<string>,
+  elementName: string,
+  value: T,
+  writeContent: ContentWriter<T>,
+  propertyName: string = elementName
+): void {
+  try {
+    writeElement(parts, elementName, value, writeContent);
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependProperty(propertyName);
+    }
+    throw error;
+  }
+}
+
+/**
+ * Write `value`, a property of the instance being serialized, as the XML element
+ * `elementName` if it has been given, and write nothing at all otherwise.
+ */
+export function writeOptionalProperty<T>(
+  parts: Array<string>,
+  elementName: string,
+  value: T | null,
+  writeContent: ContentWriter<T>,
+  propertyName: string = elementName
+): void {
+  if (value !== null) {
+    writeProperty(parts, elementName, value, writeContent, propertyName);
+  }
+}
+
+/**
+ * Write the items of `values`, each as its own whole XML element.
+ *
+ * @remarks
+ *
+ * The index is advanced only after an item has been written, so that a failure is
+ * reported at the item which actually failed.
+ */
+export function writeList<T>(
+  parts: Array<string>,
+  values: Array<T>,
+  writeItemElement: ContentWriter<T>
+): void {
+  let index = 0;
+  try {
+    for (const value of values) {
+      writeItemElement(parts, value);
+      index++;
+    }
+  } catch (error) {
+    if (error instanceof SerializationError) {
+      error.prependIndex(index);
+    }
+    throw error;
+  }
+}
+
+export function escapeXmlText(text: string): string {
+  return text
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&apos;");
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlization.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlization.ts
new file mode 100644
index 000000000..e661b15aa
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/src/xmlization.ts
@@ -0,0 +1,1274 @@
+/**
+ * Provide de/serialization of meta-model classes to/from XML.
+ *
+ * The implementation is incremental and follows a SAX-style parsing approach.
+ *
+ * @remarks
+ *
+ * The primitives which every reader and writer of XML shares -- the cursor, the
+ * checks of the namespace and the consumption of the tags -- live in
+ * the `xmlcommon` module, and so do the error classes and the path, which this
+ * module re-exports so that they stay where a caller has always found them.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurCommon from "./common";
+import * as OurTypes from "./types";
+import * as OurStringification from "./stringification";
+
+import {
+  ContentParser,
+  DeserializationError,
+  ElementSegment,
+  SerializationError,
+  XmlCursor,
+  collapseWhitespace,
+  consumeCloseTag,
+  currentTokenKind,
+  escapeXmlText,
+  localNameOfTag,
+  matchesXsBase64Binary,
+  newDeserializationError,
+  nextPropertyOpenTag,
+  parseElementContent,
+  parseList,
+  parseNamedElement,
+  parseTextContent,
+  readNextOpenTag,
+  readRequiredRootOpenTag,
+  removeWhitespace,
+  tokenizeXml,
+  writeElement,
+  writeList,
+  writeOptionalProperty,
+  writeProperty
+} from "./xmlcommon";
+
+export {
+  DeserializationError,
+  ElementSegment,
+  IndexSegment,
+  KeySegment,
+  Path,
+  SerializationError
+} from "./xmlcommon";
+export type { Segment } from "./xmlcommon";
+
+/**
+ * Read the next XML element from `cursor` and parse it with the parser which
+ * `parsersByLocalName` gives for the element's local name.
+ *
+ * An abstract class, a concrete class with descendants and a named union all
+ * prescribe no element tag of their own, so the tag is what tells us which
+ * parser to use. The set of local names which are accepted is the only thing
+ * which distinguishes one such dispatch from another, so it is the only thing
+ * which is generated -- the reading itself lives here.
+ *
+ * @param cursor - to read from
+ * @param expectedWhat - what we expected to read, for the error message
+ * @param parsersByLocalName - parser of the content, by the element's local name
+ * @returns parsed instance, or an error
+ * @typeParam T - type of the parsed instance
+ */
+function dispatchParseElement<T>(
+  cursor: XmlCursor,
+  expectedWhat: string,
+  parsersByLocalName: ReadonlyMap<string, ContentParser<T>>
+): OurCommon.Either<T, DeserializationError> {
+  const startTagOrError = readNextOpenTag(cursor);
+  if (startTagOrError.error !== null) {
+    return new OurCommon.Either<T, DeserializationError>(
+      null,
+      startTagOrError.error
+    );
+  }
+
+  const localName = localNameOfTag(startTagOrError.mustValue().tag);
+
+  const parseContent = parsersByLocalName.get(localName);
+  if (parseContent === undefined) {
+    return newDeserializationError<T>(
+      `Expected an instance of ${expectedWhat}, but got: ${localName}`
+    );
+  }
+
+  cursor.advance();
+
+  return parseElementContent(cursor, localName, parseContent);
+}
+
+/**
+ * Wrap `parseElement` so that its errors are reported at the element it parses.
+ *
+ * We use it where an instance is its own element, at the root or nested in
+ * a property, so that the path names the element of the instance, *e.g.*,
+ * `someRoot/property/someClass/someProperty`, as in the other SDKs. The items of
+ * a list and of a tuple are not wrapped, as their index already selects
+ * the element of the instance.
+ *
+ * @param parseElement - to parse the element whole, the tags included
+ * @returns the wrapped parser
+ * @typeParam T - type of the parsed instance
+ */
+function namingElement<T>(
+  parseElement: ContentParser<T>
+): ContentParser<T> {
+  return (cursor: XmlCursor) => {
+    const startTagOrError = readNextOpenTag(cursor);
+    const localName =
+      startTagOrError.error === null
+        ? localNameOfTag(startTagOrError.mustValue().tag)
+        : null;
+
+    const valueOrError = parseElement(cursor);
+    if (valueOrError.error !== null && localName !== null) {
+      valueOrError.error.path.prepend(new ElementSegment(localName));
+    }
+    return valueOrError;
+  };
+}
+
+/**
+ * Report that the property `localName` occurred more than once.
+ *
+ * The check itself sits in the property loop, right in front of the parse, since
+ * only the loop knows whether the property's variable has been set already. This
+ * is only the error, so that the message is written once instead of at every one
+ * of the property cases.
+ */
+function duplicatePropertyError(localName: string): DeserializationError {
+  return new DeserializationError(
+    "Property " + localName + " occurred more than once"
+  );
+}
+
+function parse_bool(
+  cursor: XmlCursor
+): OurCommon.Either<boolean, DeserializationError> {
+  const text = collapseWhitespace(parseTextContent(cursor));
+
+  if (text === "true" || text === "1") {
+    return new OurCommon.Either<boolean, DeserializationError>(true, null);
+  }
+  if (text === "false" || text === "0") {
+    return new OurCommon.Either<boolean, DeserializationError>(false, null);
+  }
+
+  return newDeserializationError<boolean>(
+    `Expected xs:boolean text, but got: ${text}`
+  );
+}
+
+function parse_int(
+  cursor: XmlCursor
+): OurCommon.Either<number, DeserializationError> {
+  const text = collapseWhitespace(parseTextContent(cursor));
+
+  if (!/^[+-]?\d+$/.test(text)) {
+    return newDeserializationError<number>(
+      `Expected integer text, but got: ${text}`
+    );
+  }
+
+  const value = Number(text);
+
+  // NOTE (mristin):
+  // An integer is a ``number`` in TypeScript, and a ``number`` holds only
+  // the integers up to 2^53 - 1 exactly. Beyond that ``Number`` rounds
+  // silently -- 9007199254740993 comes back as 9007199254740992, and
+  // 9223372036854775807 as 9223372036854776000, which is a perfectly
+  // well-formed but *different* xs:long. We refuse instead of corrupting.
+  //
+  // ``Number.isSafeInteger`` covers ``Number.isInteger`` as well, so
+  // a non-integer is refused here too.
+  if (!Number.isSafeInteger(value)) {
+    return newDeserializationError<number>(
+      `Expected an integer within the safe range of a number, `
+        + `but got: ${text}`
+    );
+  }
+
+  return new OurCommon.Either<number, DeserializationError>(value, null);
+}
+
+function parse_float(
+  cursor: XmlCursor
+): OurCommon.Either<number, DeserializationError> {
+  const text = collapseWhitespace(parseTextContent(cursor));
+
+  // NOTE (mristin):
+  // `+INF` is read although it is written as `INF`: XSD 1.1 admits it, its
+  // production being `(\+|-)?INF`, and being liberal in what we accept
+  // costs nothing here.
+  if (text === "INF" || text === "+INF") {
+    return new OurCommon.Either<number, DeserializationError>(Infinity, null);
+  }
+  if (text === "-INF") {
+    return new OurCommon.Either<number, DeserializationError>(-Infinity, null);
+  }
+  if (text === "NaN") {
+    return new OurCommon.Either<number, DeserializationError>(NaN, null);
+  }
+
+  // NOTE (mristin):
+  // ``Number`` is far too permissive to be trusted with the text: it reads
+  // an empty string and a run of whitespace as 0, a hexadecimal, binary or
+  // octal prefix as the number it spells -- ``0x10`` as 16 -- and
+  // ``Infinity`` as an infinity, none of which is a valid ``xs:double``.
+  //
+  // See: https://www.w3.org/TR/xmlschema-2/#double
+  if (!/^(\+|-)?([0-9]+(\.[0-9]*)?|\.[0-9]+)([Ee](\+|-)?[0-9]+)?$/.test(text)) {
+    return newDeserializationError<number>(
+      `Expected xs:double text, but got: ${text}`
+    );
+  }
+
+  const value = Number(text);
+  if (Number.isNaN(value)) {
+    return newDeserializationError<number>(
+      `Expected xs:double text, but got: ${text}`
+    );
+  }
+
+  return new OurCommon.Either<number, DeserializationError>(value, null);
+}
+
+function parse_str(
+  cursor: XmlCursor
+): OurCommon.Either<string, DeserializationError> {
+  return new OurCommon.Either<string, DeserializationError>(
+    parseTextContent(cursor),
+    null
+  );
+}
+
+function parse_bytes(
+  cursor: XmlCursor
+): OurCommon.Either<Uint8Array, DeserializationError> {
+  // NOTE (mristin):
+  // ``xs:base64Binary`` allows whitespace between the characters, and not
+  // only around them, while the decoder accepts none of it. So every
+  // whitespace character is dropped, and not merely collapsed.
+  //
+  // See: https://www.w3.org/TR/xmlschema-2/#base64Binary
+  const text = removeWhitespace(parseTextContent(cursor));
+
+  if (!matchesXsBase64Binary(text)) {
+    return newDeserializationError<Uint8Array>(
+      `Expected a text as base64-encoded bytes, but got: ${text}`
+    );
+  }
+
+  const decodedOrError = OurCommon.base64Decode(text);
+  if (decodedOrError.error !== null) {
+    return newDeserializationError<Uint8Array>(
+      decodedOrError.error
+    );
+  }
+
+  return new OurCommon.Either<Uint8Array, DeserializationError>(
+    decodedOrError.mustValue(),
+    null
+  );
+}
+
+function parseElement_SpecialItem(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.SpecialItem, DeserializationError> {
+  return parseNamedElement(
+    cursor,
+    "specialItem",
+    parseSpecialItemFromSequence
+  );
+}
+
+function parse_ListOf_IItem(
+  cursor: XmlCursor
+): OurCommon.Either<Array<OurTypes.IItem>, DeserializationError> {
+  return parseList<OurTypes.IItem>(
+    cursor,
+    dispatchParseItemElement
+  );
+}
+
+function parse_ListOf_SomeItem(
+  cursor: XmlCursor
+): OurCommon.Either<Array<OurTypes.SomeItem>, DeserializationError> {
+  return parseList<OurTypes.SomeItem>(
+    cursor,
+    dispatchParseSomeItemElement
+  );
+}
+
+function parse_ListOf_SpecialItem(
+  cursor: XmlCursor
+): OurCommon.Either<Array<OurTypes.SpecialItem>, DeserializationError> {
+  return parseList<OurTypes.SpecialItem>(
+    cursor,
+    parseElement_SpecialItem
+  );
+}
+
+/**
+ * Parse the sequence of properties of an instance
+ * of {@link types!SomeItem}.
+ *
+ * The opening tag is expected to have been already read by the caller, and
+ * the caller is expected to read and verify the corresponding closing tag
+ * after this function returns successfully. This is the contract of
+ * a `ContentParser`, so this function is used as one wherever an instance
+ * of {@link types!SomeItem} is embedded.
+ */
+function parseSomeItemFromSequence(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.SomeItem, DeserializationError> {
+  let theName: string | null = null;
+  let theNickname: string | null = null;
+
+  const className = OurTypes.SomeItem.name;
+
+  cursor.skipIgnorable();
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const nextTagOrError = nextPropertyOpenTag(cursor, className);
+    if (nextTagOrError === null) {
+      break;
+    }
+    if (nextTagOrError instanceof DeserializationError) {
+      return new OurCommon.Either<OurTypes.SomeItem, DeserializationError>(
+        null,
+        nextTagOrError
+      );
+    }
+
+    const propertyLocalName = localNameOfTag(nextTagOrError.tag);
+
+    let propertyError: DeserializationError | null = null;
+    switch (propertyLocalName) {
+      case "name": {
+        if (theName !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_str
+        );
+        propertyError = parsed.error;
+        theName = parsed.value;
+        break;
+      }
+
+      case "nickname": {
+        if (theNickname !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_str
+        );
+        propertyError = parsed.error;
+        theNickname = parsed.value;
+        break;
+      }
+
+      default: {
+        propertyError = new DeserializationError(
+          `Unexpected XML property: ${propertyLocalName}`
+        );
+        break;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(new ElementSegment(propertyLocalName));
+      return new OurCommon.Either<OurTypes.SomeItem, DeserializationError>(
+        null,
+        propertyError
+      );
+    }
+
+    cursor.skipIgnorable();
+  }
+
+  if (theName === null) {
+    return newDeserializationError<OurTypes.SomeItem>(
+      "The required property 'name' is missing"
+    );
+  }
+
+  const instance = new OurTypes.SomeItem(
+    theName,
+    theNickname
+  );
+  return new OurCommon.Either<OurTypes.SomeItem, DeserializationError>(
+    instance,
+    null
+  );
+}
+
+/**
+ * Parse the sequence of properties of an instance
+ * of {@link types!SpecialItem}.
+ *
+ * The opening tag is expected to have been already read by the caller, and
+ * the caller is expected to read and verify the corresponding closing tag
+ * after this function returns successfully. This is the contract of
+ * a `ContentParser`, so this function is used as one wherever an instance
+ * of {@link types!SpecialItem} is embedded.
+ */
+function parseSpecialItemFromSequence(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.SpecialItem, DeserializationError> {
+  let theName: string | null = null;
+  let theNickname: string | null = null;
+  let theLevel: number | null = null;
+
+  const className = OurTypes.SpecialItem.name;
+
+  cursor.skipIgnorable();
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const nextTagOrError = nextPropertyOpenTag(cursor, className);
+    if (nextTagOrError === null) {
+      break;
+    }
+    if (nextTagOrError instanceof DeserializationError) {
+      return new OurCommon.Either<OurTypes.SpecialItem, DeserializationError>(
+        null,
+        nextTagOrError
+      );
+    }
+
+    const propertyLocalName = localNameOfTag(nextTagOrError.tag);
+
+    let propertyError: DeserializationError | null = null;
+    switch (propertyLocalName) {
+      case "name": {
+        if (theName !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_str
+        );
+        propertyError = parsed.error;
+        theName = parsed.value;
+        break;
+      }
+
+      case "nickname": {
+        if (theNickname !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_str
+        );
+        propertyError = parsed.error;
+        theNickname = parsed.value;
+        break;
+      }
+
+      case "level": {
+        if (theLevel !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_int
+        );
+        propertyError = parsed.error;
+        theLevel = parsed.value;
+        break;
+      }
+
+      default: {
+        propertyError = new DeserializationError(
+          `Unexpected XML property: ${propertyLocalName}`
+        );
+        break;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(new ElementSegment(propertyLocalName));
+      return new OurCommon.Either<OurTypes.SpecialItem, DeserializationError>(
+        null,
+        propertyError
+      );
+    }
+
+    cursor.skipIgnorable();
+  }
+
+  if (theName === null) {
+    return newDeserializationError<OurTypes.SpecialItem>(
+      "The required property 'name' is missing"
+    );
+  }
+
+  if (theLevel === null) {
+    return newDeserializationError<OurTypes.SpecialItem>(
+      "The required property 'level' is missing"
+    );
+  }
+
+  const instance = new OurTypes.SpecialItem(
+    theName,
+    theLevel,
+    theNickname
+  );
+  return new OurCommon.Either<OurTypes.SpecialItem, DeserializationError>(
+    instance,
+    null
+  );
+}
+
+/**
+ * Parse the sequence of properties of an instance
+ * of {@link types!Container}.
+ *
+ * The opening tag is expected to have been already read by the caller, and
+ * the caller is expected to read and verify the corresponding closing tag
+ * after this function returns successfully. This is the contract of
+ * a `ContentParser`, so this function is used as one wherever an instance
+ * of {@link types!Container} is embedded.
+ */
+function parseContainerFromSequence(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.Container, DeserializationError> {
+  let theItems: Array<OurTypes.IItem> | null = null;
+  let theSomeItems: Array<OurTypes.SomeItem> | null = null;
+  let theSpecialItems: Array<OurTypes.SpecialItem> | null = null;
+
+  const className = OurTypes.Container.name;
+
+  cursor.skipIgnorable();
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const nextTagOrError = nextPropertyOpenTag(cursor, className);
+    if (nextTagOrError === null) {
+      break;
+    }
+    if (nextTagOrError instanceof DeserializationError) {
+      return new OurCommon.Either<OurTypes.Container, DeserializationError>(
+        null,
+        nextTagOrError
+      );
+    }
+
+    const propertyLocalName = localNameOfTag(nextTagOrError.tag);
+
+    let propertyError: DeserializationError | null = null;
+    switch (propertyLocalName) {
+      case "items": {
+        if (theItems !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_ListOf_IItem
+        );
+        propertyError = parsed.error;
+        theItems = parsed.value;
+        break;
+      }
+
+      case "someItems": {
+        if (theSomeItems !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_ListOf_SomeItem
+        );
+        propertyError = parsed.error;
+        theSomeItems = parsed.value;
+        break;
+      }
+
+      case "specialItems": {
+        if (theSpecialItems !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parse_ListOf_SpecialItem
+        );
+        propertyError = parsed.error;
+        theSpecialItems = parsed.value;
+        break;
+      }
+
+      default: {
+        propertyError = new DeserializationError(
+          `Unexpected XML property: ${propertyLocalName}`
+        );
+        break;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(new ElementSegment(propertyLocalName));
+      return new OurCommon.Either<OurTypes.Container, DeserializationError>(
+        null,
+        propertyError
+      );
+    }
+
+    cursor.skipIgnorable();
+  }
+
+  if (theItems === null) {
+    return newDeserializationError<OurTypes.Container>(
+      "The required property 'items' is missing"
+    );
+  }
+
+  if (theSomeItems === null) {
+    return newDeserializationError<OurTypes.Container>(
+      "The required property 'someItems' is missing"
+    );
+  }
+
+  const instance = new OurTypes.Container(
+    theItems,
+    theSomeItems,
+    theSpecialItems
+  );
+  return new OurCommon.Either<OurTypes.Container, DeserializationError>(
+    instance,
+    null
+  );
+}
+
+/**
+ * Parse the sequence of properties of an instance
+ * of {@link types!Wrapper}.
+ *
+ * The opening tag is expected to have been already read by the caller, and
+ * the caller is expected to read and verify the corresponding closing tag
+ * after this function returns successfully. This is the contract of
+ * a `ContentParser`, so this function is used as one wherever an instance
+ * of {@link types!Wrapper} is embedded.
+ */
+function parseWrapperFromSequence(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.Wrapper, DeserializationError> {
+  let theContainer: OurTypes.Container | null = null;
+
+  const className = OurTypes.Wrapper.name;
+
+  cursor.skipIgnorable();
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const nextTagOrError = nextPropertyOpenTag(cursor, className);
+    if (nextTagOrError === null) {
+      break;
+    }
+    if (nextTagOrError instanceof DeserializationError) {
+      return new OurCommon.Either<OurTypes.Wrapper, DeserializationError>(
+        null,
+        nextTagOrError
+      );
+    }
+
+    const propertyLocalName = localNameOfTag(nextTagOrError.tag);
+
+    let propertyError: DeserializationError | null = null;
+    switch (propertyLocalName) {
+      case "container": {
+        if (theContainer !== null) {
+          propertyError = duplicatePropertyError(propertyLocalName);
+          break;
+        }
+
+        const parsed = parseElementContent(
+          cursor,
+          propertyLocalName,
+          parseContainerFromSequence
+        );
+        propertyError = parsed.error;
+        theContainer = parsed.value;
+        break;
+      }
+
+      default: {
+        propertyError = new DeserializationError(
+          `Unexpected XML property: ${propertyLocalName}`
+        );
+        break;
+      }
+    }
+
+    if (propertyError !== null) {
+      propertyError.path.prepend(new ElementSegment(propertyLocalName));
+      return new OurCommon.Either<OurTypes.Wrapper, DeserializationError>(
+        null,
+        propertyError
+      );
+    }
+
+    cursor.skipIgnorable();
+  }
+
+  if (theContainer === null) {
+    return newDeserializationError<OurTypes.Wrapper>(
+      "The required property 'container' is missing"
+    );
+  }
+
+  const instance = new OurTypes.Wrapper(
+    theContainer
+  );
+  return new OurCommon.Either<OurTypes.Wrapper, DeserializationError>(
+    instance,
+    null
+  );
+}
+
+/**
+ * Write the properties of an instance
+ * of {@link types!SomeItem}, and neither the opening
+ * nor the closing tag of the element which holds them -- which is the contract of
+ * a `ContentWriter`, so this function is used as one.
+ */
+function writeSomeItemAsSequence(
+  parts: Array<string>,
+  that: OurTypes.SomeItem
+): void {
+  writeProperty(
+    parts,
+    "name",
+    that.name,
+    write_str
+  );
+  writeOptionalProperty(
+    parts,
+    "nickname",
+    that.nickname,
+    write_str
+  );
+}
+
+/**
+ * Write the properties of an instance
+ * of {@link types!SpecialItem}, and neither the opening
+ * nor the closing tag of the element which holds them -- which is the contract of
+ * a `ContentWriter`, so this function is used as one.
+ */
+function writeSpecialItemAsSequence(
+  parts: Array<string>,
+  that: OurTypes.SpecialItem
+): void {
+  writeProperty(
+    parts,
+    "name",
+    that.name,
+    write_str
+  );
+  writeOptionalProperty(
+    parts,
+    "nickname",
+    that.nickname,
+    write_str
+  );
+  writeProperty(
+    parts,
+    "level",
+    that.level,
+    write_int
+  );
+}
+
+/**
+ * Write the properties of an instance
+ * of {@link types!Container}, and neither the opening
+ * nor the closing tag of the element which holds them -- which is the contract of
+ * a `ContentWriter`, so this function is used as one.
+ */
+function writeContainerAsSequence(
+  parts: Array<string>,
+  that: OurTypes.Container
+): void {
+  writeProperty(
+    parts,
+    "items",
+    that.items,
+    writeListOfInstances
+  );
+  writeProperty(
+    parts,
+    "someItems",
+    that.someItems,
+    writeListOfInstances
+  );
+  writeOptionalProperty(
+    parts,
+    "specialItems",
+    that.specialItems,
+    writeListOfInstances
+  );
+}
+
+/**
+ * Write the properties of an instance
+ * of {@link types!Wrapper}, and neither the opening
+ * nor the closing tag of the element which holds them -- which is the contract of
+ * a `ContentWriter`, so this function is used as one.
+ */
+function writeWrapperAsSequence(
+  parts: Array<string>,
+  that: OurTypes.Wrapper
+): void {
+  writeProperty(
+    parts,
+    "container",
+    that.container,
+    writeContainerAsSequence
+  );
+}
+
+const PARSERS_OF_ITEM = new Map<
+  string,
+  ContentParser<OurTypes.IItem>
+>([
+  ["someItem", parseSomeItemFromSequence],
+  ["specialItem", parseSpecialItemFromSequence]
+]);
+
+/**
+ * Dispatch-parse an instance
+ * of {@link types!IItem} from the next
+ * XML element in `cursor`, based on the element's local name.
+ *
+ * @param cursor - to read from
+ * @returns the parsed instance, or an error
+ */
+function dispatchParseItemElement(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.IItem, DeserializationError> {
+  return dispatchParseElement(
+    cursor,
+    "IItem",
+    PARSERS_OF_ITEM
+  );
+}
+
+/**
+ * Parse an XML string as an instance
+ * of {@link types!IItem}.
+ *
+ * @param xml - XML string to parse
+ * @returns parsed instance, or an error
+ */
+export function itemFromXmlString(
+  xml: string
+): OurCommon.Either<OurTypes.IItem, DeserializationError> {
+  if (xml.length === 0) {
+    return newDeserializationError<OurTypes.IItem>(
+      "Expected an XML document, but got an empty string"
+    );
+  }
+
+  const tokensOrError = tokenizeXml(xml);
+  if (tokensOrError.error !== null) {
+    return new OurCommon.Either<OurTypes.IItem, DeserializationError>(
+      null,
+      tokensOrError.error
+    );
+  }
+
+  const cursor = new XmlCursor(tokensOrError.mustValue());
+
+  const instanceOrError = namingElement(dispatchParseItemElement)(cursor);
+  if (instanceOrError.error !== null) {
+    return instanceOrError;
+  }
+
+  cursor.skipIgnorable();
+  if (cursor.current() !== null) {
+    return newDeserializationError<OurTypes.IItem>(
+      "Expected no tokens after the root XML element, but got token kind: " +
+        currentTokenKind(cursor)
+    );
+  }
+
+  return instanceOrError;
+}
+
+const PARSERS_OF_SOME_ITEM = new Map<
+  string,
+  ContentParser<OurTypes.SomeItem>
+>([
+  ["specialItem", parseSpecialItemFromSequence],
+  ["someItem", parseSomeItemFromSequence]
+]);
+
+/**
+ * Dispatch-parse an instance
+ * of {@link types!SomeItem} from the next
+ * XML element in `cursor`, based on the element's local name.
+ *
+ * @param cursor - to read from
+ * @returns the parsed instance, or an error
+ */
+function dispatchParseSomeItemElement(
+  cursor: XmlCursor
+): OurCommon.Either<OurTypes.SomeItem, DeserializationError> {
+  return dispatchParseElement(
+    cursor,
+    "SomeItem",
+    PARSERS_OF_SOME_ITEM
+  );
+}
+
+/**
+ * Parse an XML string as an instance
+ * of {@link types!SomeItem}.
+ *
+ * @param xml - XML string to parse
+ * @returns parsed instance, or an error
+ */
+export function someItemFromXmlString(
+  xml: string
+): OurCommon.Either<OurTypes.SomeItem, DeserializationError> {
+  if (xml.length === 0) {
+    return newDeserializationError<OurTypes.SomeItem>(
+      "Expected an XML document, but got an empty string"
+    );
+  }
+
+  const tokensOrError = tokenizeXml(xml);
+  if (tokensOrError.error !== null) {
+    return new OurCommon.Either<OurTypes.SomeItem, DeserializationError>(
+      null,
+      tokensOrError.error
+    );
+  }
+
+  const cursor = new XmlCursor(tokensOrError.mustValue());
+
+  const instanceOrError = namingElement(dispatchParseSomeItemElement)(cursor);
+  if (instanceOrError.error !== null) {
+    return instanceOrError;
+  }
+
+  cursor.skipIgnorable();
+  if (cursor.current() !== null) {
+    return newDeserializationError<OurTypes.SomeItem>(
+      "Expected no tokens after the root XML element, but got token kind: " +
+        currentTokenKind(cursor)
+    );
+  }
+
+  return instanceOrError;
+}
+
+const ROOT_DISPATCH_BY_LOCAL_NAME = new Map<
+  string,
+  ContentParser<OurTypes.Class>
+>([
+  ["someItem", parseSomeItemFromSequence],
+  ["specialItem", parseSpecialItemFromSequence],
+  ["container", parseContainerFromSequence],
+  ["wrapper", parseWrapperFromSequence]
+]);
+
+/**
+ * Parse an XML string as a model instance.
+ *
+ * @param xml - XML string to parse
+ * @returns parsed model instance or an error
+ */
+export function fromXmlString(
+  xml: string
+): OurCommon.Either<OurTypes.Class, DeserializationError> {
+  if (xml.length === 0) {
+    return newDeserializationError<OurTypes.Class>(
+      "Expected an XML document, but got an empty string"
+    );
+  }
+
+  const tokensOrError = tokenizeXml(xml);
+  if (tokensOrError.error !== null) {
+    return new OurCommon.Either<OurTypes.Class, DeserializationError>(
+      null,
+      tokensOrError.error
+    );
+  }
+
+  const cursor = new XmlCursor(tokensOrError.mustValue());
+
+  const rootOpenTagOrError = readRequiredRootOpenTag(cursor);
+  if (rootOpenTagOrError.error !== null) {
+    return new OurCommon.Either<OurTypes.Class, DeserializationError>(
+      null,
+      rootOpenTagOrError.error
+    );
+  }
+
+  const rootOpenTag = rootOpenTagOrError.mustValue();
+  const rootLocalName = localNameOfTag(rootOpenTag.tag);
+
+  // NOTE (mristin):
+  // The errors within the root element are reported at it, as in the other SDKs.
+  const dispatch = ROOT_DISPATCH_BY_LOCAL_NAME.get(rootLocalName);
+  if (dispatch === undefined) {
+    const error = new DeserializationError(
+      `Unexpected root XML element: ${rootLocalName}`
+    );
+    error.path.prepend(new ElementSegment(rootLocalName));
+    return new OurCommon.Either<OurTypes.Class, DeserializationError>(
+      null,
+      error
+    );
+  }
+
+  const instanceOrError = dispatch(cursor);
+  if (instanceOrError.error !== null) {
+    instanceOrError.error.path.prepend(new ElementSegment(rootLocalName));
+    return instanceOrError;
+  }
+
+  const closeError = consumeCloseTag(cursor, rootLocalName);
+  if (closeError !== null) {
+    closeError.path.prepend(new ElementSegment(rootLocalName));
+    return new OurCommon.Either<OurTypes.Class, DeserializationError>(
+      null,
+      closeError
+    );
+  }
+
+  cursor.skipIgnorable();
+  if (cursor.current() !== null) {
+    return newDeserializationError<OurTypes.Class>(
+      "Expected no tokens after the root XML element, but got token kind: " +
+        currentTokenKind(cursor)
+    );
+  }
+
+  return instanceOrError;
+}
+
+/**
+ * Write the instances of `values`, each as its own, self-describing XML element.
+ *
+ * @remarks
+ *
+ * Every item goes through {@link writeClass} whatever its declared type is, so
+ * this one writer serves every list of instances in the meta-model.
+ */
+function writeListOfInstances(
+  parts: Array<string>,
+  values: Array<OurTypes.Class>
+): void {
+  writeList(parts, values, writeClass);
+}
+
+/**
+ * Write `that` as its own, self-describing XML element.
+ *
+ * @remarks
+ *
+ * Which element that is, is decided by the run-time type of `that`, so this one
+ * writer serves every abstract class, every named union, and the item of a list
+ * or of a tuple of any class at all. The reading, which has to decide what to
+ * construct before it has read anything, needs a dispatcher per interface instead.
+ */
+function writeClass(parts: Array<string>, that: OurTypes.Class): void {
+  SERIALIZER.visitWithContext(that, parts);
+}
+
+/**
+ * Write the literal `value` of the enumeration `enumerationName` as the content
+ * of an XML element.
+ *
+ * @remarks
+ *
+ * We deliberately go through the `toString` of the stringification module, which
+ * gives out `null` for a literal it does not know, and not through its `mustToString`,
+ * which throws an error of its own. An instance carrying a literal outside its
+ * enumeration is exactly the kind of failure this module reports with a path.
+ */
+function writeEnumerationContent<T>(
+  parts: Array<string>,
+  value: T,
+  enumerationName: string,
+  toString: (value: T) => string | null
+): void {
+  const text = toString(value);
+  if (text === null) {
+    throw new SerializationError(
+      `Invalid literal of ${enumerationName}: ${value}`
+    );
+  }
+
+  parts.push(escapeXmlText(text));
+}
+
+function write_bool(
+  parts: Array<string>,
+  value: boolean
+): void {
+  parts.push(value ? "true" : "false");
+}
+
+function write_int(
+  parts: Array<string>,
+  value: number
+): void {
+  // NOTE (mristin):
+  // Beyond 2^53 - 1 a ``number`` no longer holds every integer, so the value
+  // we were handed has already lost its identity -- writing it out would
+  // record a different xs:long without a word. ``Number.isSafeInteger``
+  // covers ``Number.isInteger`` as well.
+  if (!Number.isSafeInteger(value)) {
+    throw new SerializationError(
+      `Expected an integer within the safe range of a number, `
+        + `but got: ${value}`
+    );
+  }
+
+  parts.push(`${value}`);
+}
+
+function write_float(
+  parts: Array<string>,
+  value: number
+): void {
+  if (Number.isNaN(value)) {
+    parts.push("NaN");
+  } else if (value === Infinity) {
+    parts.push("INF");
+  } else if (value === -Infinity) {
+    parts.push("-INF");
+  } else if (Object.is(value, -0)) {
+    // NOTE (mristin):
+    // ``${-0}`` is "0", so the sign would be dropped, and a negative zero
+    // would come back as a positive one. ``-0`` is a valid xs:double, and
+    // the other SDKs keep the sign, so we keep it too. Mind that
+    // ``value === -0`` is true for a positive zero as well, which is why
+    // this asks ``Object.is``.
+    parts.push("-0");
+  } else {
+    parts.push(`${value}`);
+  }
+}
+
+function write_str(
+  parts: Array<string>,
+  value: string
+): void {
+  parts.push(escapeXmlText(value));
+}
+
+function write_bytes(
+  parts: Array<string>,
+  value: Uint8Array
+): void {
+  parts.push(escapeXmlText(OurCommon.base64Encode(value)));
+}
+
+/**
+ * Write the XML element of an instance, dispatching on its run-time type.
+ *
+ * Each method writes the whole element -- the tags included -- since the element
+ * is picked by the run-time type, which this dispatch has just established. The
+ * properties are written by the corresponding module-level `write{Cls}AsSequence`,
+ * which is the content writer of that very element.
+ */
+class Serializer extends OurTypes.AbstractVisitorWithContext<Array<string>> {
+  visitSomeItemWithContext(
+    that: OurTypes.SomeItem,
+    parts: Array<string>
+  ): void {
+    writeElement(
+      parts,
+      "someItem",
+      that,
+      writeSomeItemAsSequence
+    );
+  }
+
+  visitSpecialItemWithContext(
+    that: OurTypes.SpecialItem,
+    parts: Array<string>
+  ): void {
+    writeElement(
+      parts,
+      "specialItem",
+      that,
+      writeSpecialItemAsSequence
+    );
+  }
+
+  visitContainerWithContext(
+    that: OurTypes.Container,
+    parts: Array<string>
+  ): void {
+    writeElement(
+      parts,
+      "container",
+      that,
+      writeContainerAsSequence
+    );
+  }
+
+  visitWrapperWithContext(
+    that: OurTypes.Wrapper,
+    parts: Array<string>
+  ): void {
+    writeElement(
+      parts,
+      "wrapper",
+      that,
+      writeWrapperAsSequence
+    );
+  }
+}
+
+const SERIALIZER = new Serializer();
+
+/**
+ * Serialize a model instance as an XML string.
+ *
+ * @param that - model instance to serialize
+ * @returns serialized XML string
+ * @throws {@link SerializationError} if `that` can not be serialized, *e.g.*, if
+ * a property expected to be an integer holds a fractional number
+ */
+export function toXmlString(that: OurTypes.Class): string {
+  const parts = new Array<string>();
+  writeClass(parts, that);
+  return parts.join("");
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64.spec.ts
new file mode 100644
index 000000000..75ec0d285
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64.spec.ts
@@ -0,0 +1,212 @@
+/**
+ * Test base64 encoding and decoding.
+ */
+
+import * as OurCommon from "../src/common";
+
+function testEncodeDecode(text: string, expectedEncoded: string): void {
+  const bytes = Uint8Array.from(text.split("").map((c) => c.charCodeAt(0)));
+
+  const encoded = OurCommon.base64Encode(bytes);
+  expect(encoded).toEqual(expectedEncoded);
+
+  const decodedOrError: OurCommon.Either<Uint8Array, string> =
+    OurCommon.base64Decode(encoded);
+
+  expect(decodedOrError.error).toBeNull();
+  expect(decodedOrError.mustValue()).toEqual(bytes);
+}
+
+// NOTE (mristin):
+// The following tests come from:
+// https://www.rfc-editor.org/rfc/rfc4648#section-10
+
+test("empty", () => {
+  testEncodeDecode("", "");
+});
+
+test("Uint8Array from 'f' is encoded 'Zg=='", () => {
+  testEncodeDecode("f", "Zg==");
+});
+
+test("Uint8Array from 'fo' is encoded 'Zm8='", () => {
+  testEncodeDecode("fo", "Zm8=");
+});
+
+test("Uint8Array from 'foo' is encoded 'Zm9v'", () => {
+  testEncodeDecode("foo", "Zm9v");
+});
+
+test("Uint8Array from 'foob' is encoded 'Zm9vYg=='", () => {
+  testEncodeDecode("foob", "Zm9vYg==");
+});
+
+test("Uint8Array from 'fooba' is encoded 'Zm9vYmE='", () => {
+  testEncodeDecode("fooba", "Zm9vYmE=");
+});
+
+test("Uint8Array from 'foobar' is encoded 'Zm9vYmFy'", () => {
+  testEncodeDecode("foobar", "Zm9vYmFy");
+});
+
+test("unexpected padding in the middle", () => {
+  const encoded = "Zm9vYmFy";
+
+  for (let i = 0; i < encoded.length - 1; i++) {
+    const badEncoded =
+      encoded.substring(0, i) + "=" + encoded.substring(i + 1, encoded.length);
+
+    // Test the test
+    expect(badEncoded.length).toEqual(encoded.length);
+
+    const decodedOrError = OurCommon.base64Decode(badEncoded);
+    expect(decodedOrError.error).toEqual(
+      "Expected a valid character from " +
+        "base64-encoded string, but got at " +
+        `index ${i}: = (code: 61)`
+    );
+  }
+});
+
+test("Bytes representing an invalid UTF-8 sequence encode OK", () => {
+  // NOTE (mristin):
+  // We simply add a test to make sure our implementation does not suffer from
+  // issues raised in:
+  // https://stackoverflow.com/questions/30106476/using-javascripts-atob-to-decode-base64-doesnt-properly-decode-utf-8-strings
+
+  // From:
+  // https://stackoverflow.com/questions/1301402/example-invalid-utf8-string
+  const bytes = new Uint8Array([0xc3, 0x28]);
+
+  // NOTE (mristin):
+  // This encoding was obtained by Python `base64` module.
+  const expectedEncoded = "wyg=";
+
+  const encoded = OurCommon.base64Encode(bytes);
+  expect(encoded).toEqual(expectedEncoded);
+
+  const decodedOrError: OurCommon.Either<Uint8Array, string> =
+    OurCommon.base64Decode(encoded);
+
+  expect(decodedOrError.error).toBeNull();
+  expect(decodedOrError.mustValue()).toEqual(bytes);
+});
+
+// NOTE (mristin):
+// The following checks come from: https://eprint.iacr.org/2022/361.pdf
+
+test("'Hello' as 'SGVsbG8=' OK", () => {
+  testEncodeDecode("Hello", "SGVsbG8=");
+});
+
+test("our implementation suffers from padding inconsistency of 'Hello' as 'SGVsbG9='", () => {
+  // NOTE (mristin):
+  // This is not a test case, but we merely document that there is a possible
+  // attack vector where different strings encode the *same* byte sequence.
+
+  const badEncoded = "SGVsbG9=";
+
+  const decodedOrError = OurCommon.base64Decode(badEncoded);
+  expect(decodedOrError.mustValue()).toEqual(
+    new Uint8Array(
+      // "Hello"
+      [72, 101, 108, 108, 111]
+    )
+  );
+  expect(decodedOrError.error).toBeNull();
+});
+
+test("table from rickkas7/Base64RK", () => {
+  // NOTE (mristin):
+  // The following tests have been scraped from:
+  // https://github.com/rickkas7/Base64RK/blob/183d20e62b96ef9b0230c80c7a172715ca6f661e/test/unit-test/unit-test.cpp
+
+  const arraysExpectedEncodeds: Array<[Array<number>, string]> = [
+    [[28], "HA=="],
+    [[174, 208], "rtA="],
+    [[50, 224, 208], "MuDQ"],
+    [[45, 18, 235, 6], "LRLrBg=="],
+    [[117, 199, 153, 221, 160], "dceZ3aA="],
+    [[141, 12, 188, 48, 173, 45], "jQy8MK0t"],
+    [[69, 143, 148, 125, 213, 3, 148], "RY+UfdUDlA=="],
+    [[251, 162, 166, 60, 129, 131, 46, 13], "+6KmPIGDLg0="],
+    [[207, 40, 204, 254, 77, 71, 61, 8, 128], "zyjM/k1HPQiA"],
+    [[156, 150, 213, 174, 117, 59, 70, 220, 210, 63], "nJbVrnU7RtzSPw=="],
+    [[192, 54, 173, 19, 126, 84, 26, 250, 167, 5, 50], "wDatE35UGvqnBTI="],
+    [[20, 1, 15, 77, 224, 141, 153, 47, 186, 170, 200, 227], "FAEPTeCNmS+6qsjj"],
+    [
+      [85, 166, 130, 169, 193, 117, 194, 81, 238, 64, 180, 228, 127],
+      "VaaCqcF1wlHuQLTkfw=="
+    ],
+    [
+      [65, 130, 145, 17, 247, 99, 158, 36, 117, 8, 192, 1, 193, 234],
+      "QYKREfdjniR1CMABweo="
+    ],
+    [
+      [9, 55, 253, 179, 203, 93, 237, 58, 252, 200, 168, 145, 115, 53, 31],
+      "CTf9s8td7Tr8yKiRczUf"
+    ],
+    [
+      [
+        254, 76, 140, 77, 16, 52, 119, 229, 186, 225, 109, 181, 134, 34, 229, 153, 235,
+        1, 16, 126, 17, 14, 13, 12, 138, 248, 230, 60, 73, 128, 116, 204, 207
+      ],
+      "/kyMTRA0d+W64W21hiLlmesBEH4RDg0MivjmPEmAdMzP"
+    ],
+    [
+      [
+        155, 159, 208, 168, 221, 216, 113, 8, 58, 136, 77, 93, 86, 50, 80, 91, 14, 102,
+        10, 54, 2, 158, 195, 75, 40, 245, 84, 177, 116, 54, 235, 217, 124, 232, 205,
+        113, 111, 33, 231, 251, 246, 136, 41, 167, 201, 234, 20, 83, 225, 67, 131, 210,
+        97, 194, 1, 252, 158, 253, 84, 135, 119, 1, 254, 11, 182, 208
+      ],
+      "m5/QqN3YcQg6iE1dVjJQWw5mCjYCnsNLKPVUsXQ269l86M1xbyHn+/aIKafJ6hRT4UOD0mHCAfye/VSHdwH+C7bQ"
+    ],
+    [
+      [
+        101, 43, 33, 221, 108, 128, 221, 221, 52, 11, 40, 166, 120, 198, 79, 0, 141,
+        127, 183, 226, 197, 232, 52, 29, 136, 1, 16, 27, 216, 71, 149, 251, 131, 94, 22,
+        118, 25, 255, 214, 119, 91, 182, 203, 228, 67, 22, 88, 180, 161, 42, 182, 125,
+        183, 239, 186, 216, 23, 11, 17, 144, 124, 201, 177, 3, 83, 68, 131, 249, 52,
+        189, 2, 28, 74, 172, 214, 117, 126, 249, 239, 90, 22, 204, 161, 243, 232, 166,
+        103, 150, 20, 240, 60, 93, 187, 67, 57, 231, 1, 102, 221, 194, 76, 162, 8, 89,
+        72, 150, 146, 247, 181, 134, 242, 205, 179, 19, 155, 68, 94, 82, 214, 56, 1,
+        111, 109, 78, 155, 216, 73, 7, 80, 243
+      ],
+      "ZSsh3WyA3d00CyimeMZPAI1/t+LF6DQdiAEQG9hHlfuDXhZ2Gf/Wd1u2y+RDFli0oSq2fbfvutgXCxGQfMmxA1NEg/k0vQIcSqzWdX7571oWzKHz6KZnlhTwPF27QznnAWbdwkyiCFlIlpL3tYbyzbMTm0ReUtY4AW9tTpvYSQdQ8w=="
+    ],
+    [
+      [
+        177, 224, 149, 210, 54, 194, 123, 141, 157, 224, 99, 1, 189, 114, 37, 230, 250,
+        149, 161, 158, 138, 226, 5, 18, 131, 169, 202, 130, 46, 109, 102, 35, 113, 199,
+        109, 178, 98, 137, 249, 69, 227, 130, 232, 246, 105, 101, 97, 234, 120, 151, 31,
+        41, 90, 20, 15, 246, 90, 214, 39, 139, 86, 52, 78, 174, 35, 95, 63, 226, 241,
+        127, 164, 219, 174, 140, 255, 17, 120, 118, 97, 131, 133, 35, 231, 117, 215, 74,
+        14, 110, 70, 42, 110, 7, 37, 234, 139, 210, 224, 36, 71, 227, 68, 155, 236, 191,
+        61, 83, 11, 189, 88, 60, 208, 3, 109, 121, 32, 71, 169, 58, 125, 112, 116, 16,
+        153, 200, 74, 242, 89, 141, 143, 25, 211, 92, 179, 227, 223, 183, 219, 18, 54,
+        208, 80, 253, 11, 76, 69, 150, 4, 48, 238, 73, 165, 25, 133, 200, 80, 207, 84,
+        182, 64, 251, 156, 76, 255, 112, 227, 235, 154, 29, 191, 86, 217, 118, 219, 51,
+        38, 173, 6, 111, 14, 55, 195, 13, 45, 236, 66, 180, 39, 109, 110, 7, 47, 61,
+        103, 100, 117, 55, 89, 35, 64, 106, 106, 42, 238, 37, 70, 20, 8, 128, 34, 131,
+        56, 120, 103, 125, 149, 182, 130, 217, 38, 102, 24, 170, 111, 47, 113, 79, 142,
+        4, 167, 80, 12, 174, 102, 74, 129, 109, 204, 12, 252, 200, 95, 97, 51, 215, 169,
+        148, 191, 113, 155, 228, 145, 235, 35, 252, 53, 177
+      ],
+      "seCV0jbCe42d4GMBvXIl5vqVoZ6K4gUSg6nKgi5tZiNxx22yYon5ReOC6PZpZWHqeJcfKVoUD/Za1ieLVjROriNfP+Lxf6Tbroz/EXh2YYOFI+d110oObkYqbgcl6ovS4CRH40Sb7L89Uwu9WDzQA215IEepOn1wdBCZyEryWY2PGdNcs+Pft9sSNtBQ/QtMRZYEMO5JpRmFyFDPVLZA+5xM/3Dj65odv1bZdtszJq0Gbw43ww0t7EK0J21uBy89Z2R1N1kjQGpqKu4lRhQIgCKDOHhnfZW2gtkmZhiqby9xT44Ep1AMrmZKgW3MDPzIX2Ez16mUv3Gb5JHrI/w1sQ=="
+    ]
+  ];
+
+  for (const [array, expectedEncoded] of arraysExpectedEncodeds) {
+    const bytes = new Uint8Array(array);
+
+    const encoded = OurCommon.base64Encode(bytes);
+    expect(encoded).toEqual(expectedEncoded);
+
+    const decodedOrError: OurCommon.Either<Uint8Array, string> =
+      OurCommon.base64Decode(encoded);
+
+    expect(decodedOrError.error).toBeNull();
+    expect(decodedOrError.mustValue()).toEqual(bytes);
+  }
+});
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64url.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64url.spec.ts
new file mode 100644
index 000000000..9bd7d0d77
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.base64url.spec.ts
@@ -0,0 +1,145 @@
+/**
+ * Test base64url encoding and decoding.
+ */
+
+import * as OurCommon from "../src/common";
+
+function testBase64UrlEncodeDecode(text: string, expectedEncoded: string): void {
+  const bytes = Uint8Array.from(text.split("").map((c) => c.charCodeAt(0)));
+
+  const encoded = OurCommon.base64UrlEncode(bytes);
+  expect(encoded).toEqual(expectedEncoded);
+
+  const decodedOrError: OurCommon.Either<Uint8Array, string> =
+    OurCommon.base64UrlDecode(encoded);
+
+  expect(decodedOrError.error).toBeNull();
+  expect(decodedOrError.mustValue()).toEqual(bytes);
+}
+
+test("empty string", () => {
+  testBase64UrlEncodeDecode("", "");
+});
+
+test("'f' is encoded 'Zg'", () => {
+  testBase64UrlEncodeDecode("f", "Zg");
+});
+
+test("'fo' is encoded 'Zm8'", () => {
+  testBase64UrlEncodeDecode("fo", "Zm8");
+});
+
+test("'foo' is encoded 'Zm9v'", () => {
+  testBase64UrlEncodeDecode("foo", "Zm9v");
+});
+
+test("'foob' is encoded 'Zm9vYg'", () => {
+  testBase64UrlEncodeDecode("foob", "Zm9vYg");
+});
+
+test("'fooba' is encoded 'Zm9vYmE'", () => {
+  testBase64UrlEncodeDecode("fooba", "Zm9vYmE");
+});
+
+test("'foobar' is encoded 'Zm9vYmFy'", () => {
+  testBase64UrlEncodeDecode("foobar", "Zm9vYmFy");
+});
+
+test("RFC 4648 test vectors", () => {
+  const testVectors: Array<[string, string]> = [
+    ["", ""],
+    ["f", "Zg"],
+    ["fo", "Zm8"],
+    ["foo", "Zm9v"],
+    ["foob", "Zm9vYg"],
+    ["fooba", "Zm9vYmE"],
+    ["foobar", "Zm9vYmFy"]
+  ];
+
+  for (const [input, expected] of testVectors) {
+    testBase64UrlEncodeDecode(input, expected);
+  }
+});
+
+test("characters that differ from base64", () => {
+  const bytes = new Uint8Array([0x3e, 0x3f, 0xfc, 0xff]);
+
+  const base64 = OurCommon.base64Encode(bytes);
+  const base64url = OurCommon.base64UrlEncode(bytes);
+
+  expect(base64).toEqual("Pj/8/w==");
+  expect(base64url).toEqual("Pj_8_w");
+  expect(base64url).not.toContain("+");
+  expect(base64url).not.toContain("/");
+  expect(base64url).not.toContain("=");
+});
+
+test("decode with missing padding", () => {
+  const testCases = ["Zg", "Zm8", "Zm9vYg", "Zm9vYmE"];
+
+  for (const encoded of testCases) {
+    const decodedOrError = OurCommon.base64UrlDecode(encoded);
+    expect(decodedOrError.error).toBeNull();
+  }
+});
+
+test("decode URL-safe characters", () => {
+  const encoded = "Pj_8_w";
+  const decodedOrError = OurCommon.base64UrlDecode(encoded);
+
+  expect(decodedOrError.error).toBeNull();
+  expect(decodedOrError.mustValue()).toEqual(new Uint8Array([0x3e, 0x3f, 0xfc, 0xff]));
+});
+
+test("round-trip with binary data", () => {
+  const bytes = new Uint8Array(256);
+  for (let i = 0; i < 256; i++) {
+    bytes[i] = i;
+  }
+
+  const encoded = OurCommon.base64UrlEncode(bytes);
+  const decodedOrError = OurCommon.base64UrlDecode(encoded);
+
+  expect(decodedOrError.error).toBeNull();
+  expect(decodedOrError.mustValue()).toEqual(bytes);
+  expect(encoded).not.toContain("+");
+  expect(encoded).not.toContain("/");
+  expect(encoded).not.toContain("=");
+});
+
+test("specific byte sequences that produce URL-unsafe characters", () => {
+  const testCases: Array<[number[], string]> = [
+    [[62], "Pg"],
+    [[63], "Pw"],
+    [[250], "-g"], // Base64 would start with `+`
+    [[251], "-w"],
+    [[252], "_A"], // Base64 would start with `/`
+    [[253], "_Q"],
+    [[254], "_g"],
+    [[255], "_w"],
+    [[62, 63], "Pj8"],
+    [[252, 253], "_P0"],
+    [[254, 255], "_v8"]
+  ];
+
+  for (const [numberArray, expectedEncoded] of testCases) {
+    const bytes = new Uint8Array(numberArray);
+    const encoded = OurCommon.base64UrlEncode(bytes);
+
+    expect(encoded).toEqual(expectedEncoded);
+
+    const decodedOrError = OurCommon.base64UrlDecode(encoded);
+    expect(decodedOrError.error).toBeNull();
+    expect(decodedOrError.mustValue()).toEqual(bytes);
+  }
+});
+
+test("invalid characters in input", () => {
+  const invalidInputs = ["Zm9v+", "Zm9v/", "Zm9v=", "Zm9v YmFy", "Zm9v\n", "Zm9v\t"];
+
+  for (const invalid of invalidInputs) {
+    const decodedOrError = OurCommon.base64UrlDecode(invalid);
+    expect(decodedOrError.error).not.toBeNull();
+    expect(decodedOrError.value).toBeNull();
+  }
+});
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.stringHelpers.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.stringHelpers.spec.ts
new file mode 100644
index 000000000..84ea2c591
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.stringHelpers.spec.ts
@@ -0,0 +1,205 @@
+/**
+ * Test `len`, the slicing of strings and `find` as used in the transpiled code.
+ *
+ * @remarks
+ * The transpiled code follows the Python implementation, since Python is
+ * the language of the meta-model specifications. Hence, the lengths and
+ * the positions count the characters (code points). The expected values have
+ * been computed with Python, and all the SDKs test against the very same cases.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurCommon from "../src/common";
+
+test("len('') gives 0: empty text", () => {
+  expect(OurCommon.lenStr("")).toStrictEqual(0);
+});
+
+test("len('abc') gives 3: ASCII text", () => {
+  expect(OurCommon.lenStr("abc")).toStrictEqual(3);
+});
+
+test("len('é-') gives 2: character of two UTF-8 bytes", () => {
+  expect(OurCommon.lenStr("é-")).toStrictEqual(2);
+});
+
+test("len('😀-') gives 2: character beyond the Basic Multilingual Plane", () => {
+  expect(OurCommon.lenStr("😀-")).toStrictEqual(2);
+});
+
+test("len('aé😀b😀') gives 5: mixed characters", () => {
+  expect(OurCommon.lenStr("aé😀b😀")).toStrictEqual(5);
+});
+
+test("'abcde'[1:3] gives 'bc': start and end", () => {
+  expect(OurCommon.sliceStr("abcde", 1, 3)).toStrictEqual("bc");
+});
+
+test("'abcde'[:2] gives 'ab': no start", () => {
+  expect(OurCommon.sliceStr("abcde", 0, 2)).toStrictEqual("ab");
+});
+
+test("'abcde'[3:] gives 'de': no end", () => {
+  expect(OurCommon.sliceStr("abcde", 3)).toStrictEqual("de");
+});
+
+test("'abcde'[:] gives 'abcde': neither start nor end", () => {
+  expect(OurCommon.sliceStr("abcde", 0)).toStrictEqual("abcde");
+});
+
+test("'abcde'[-2:] gives 'de': negative start counts from the end", () => {
+  expect(OurCommon.sliceStr("abcde", -2)).toStrictEqual("de");
+});
+
+test("'abcde'[:-2] gives 'abc': negative end counts from the end", () => {
+  expect(OurCommon.sliceStr("abcde", 0, -2)).toStrictEqual("abc");
+});
+
+test("'abcde'[-4:-1] gives 'bcd': negative start and end", () => {
+  expect(OurCommon.sliceStr("abcde", -4, -1)).toStrictEqual("bcd");
+});
+
+test("'abcde'[-10:2] gives 'ab': negative start before the beginning is clamped", () => {
+  expect(OurCommon.sliceStr("abcde", -10, 2)).toStrictEqual("ab");
+});
+
+test("'abcde'[2:10] gives 'cde': end beyond the end is clamped", () => {
+  expect(OurCommon.sliceStr("abcde", 2, 10)).toStrictEqual("cde");
+});
+
+test("'abcde'[10:] gives '': start beyond the end gives empty", () => {
+  expect(OurCommon.sliceStr("abcde", 10)).toStrictEqual("");
+});
+
+test("'abcde'[3:1] gives '': start after end gives empty", () => {
+  expect(OurCommon.sliceStr("abcde", 3, 1)).toStrictEqual("");
+});
+
+test("'abcde'[-1:-3] gives '': negative start after negative end gives empty", () => {
+  expect(OurCommon.sliceStr("abcde", -1, -3)).toStrictEqual("");
+});
+
+test("'abcde'[5:5] gives '': start equal to end gives empty", () => {
+  expect(OurCommon.sliceStr("abcde", 5, 5)).toStrictEqual("");
+});
+
+test("''[0:0] gives '': empty text", () => {
+  expect(OurCommon.sliceStr("", 0, 0)).toStrictEqual("");
+});
+
+test("''[-1:] gives '': negative start on empty text", () => {
+  expect(OurCommon.sliceStr("", -1)).toStrictEqual("");
+});
+
+test("''[:5] gives '': end beyond the end of empty text", () => {
+  expect(OurCommon.sliceStr("", 0, 5)).toStrictEqual("");
+});
+
+test("'é-x'[1:] gives '-x': after a character of two UTF-8 bytes", () => {
+  expect(OurCommon.sliceStr("é-x", 1)).toStrictEqual("-x");
+});
+
+test("'aéb'[1:2] gives 'é': character of two UTF-8 bytes", () => {
+  expect(OurCommon.sliceStr("aéb", 1, 2)).toStrictEqual("é");
+});
+
+test("'a😀b'[1:2] gives '😀': character beyond the Basic Multilingual Plane", () => {
+  expect(OurCommon.sliceStr("a😀b", 1, 2)).toStrictEqual("😀");
+});
+
+test("'😀-x'[1:] gives '-x': after a character beyond the Basic Multilingual Plane", () => {
+  expect(OurCommon.sliceStr("😀-x", 1)).toStrictEqual("-x");
+});
+
+test("'aé😀b😀'[-3:-1] gives '😀b': negative start on characters beyond ASCII", () => {
+  expect(OurCommon.sliceStr("aé😀b😀", -3, -1)).toStrictEqual("😀b");
+});
+
+test("'abcabc'.find('b') gives 1: found", () => {
+  expect(OurCommon.findStr("abcabc", "b")).toStrictEqual(1);
+});
+
+test("'abcabc'.find('x') gives -1: not found", () => {
+  expect(OurCommon.findStr("abcabc", "x")).toStrictEqual(-1);
+});
+
+test("'abcabc'.find('') gives 0: empty sub", () => {
+  expect(OurCommon.findStr("abcabc", "")).toStrictEqual(0);
+});
+
+test("'ab'.find('abc') gives -1: sub longer than text", () => {
+  expect(OurCommon.findStr("ab", "abc")).toStrictEqual(-1);
+});
+
+test("'abcabc'.find('b', 2) gives 4: found after start", () => {
+  expect(OurCommon.findStr("abcabc", "b", 2)).toStrictEqual(4);
+});
+
+test("'abcabc'.find('b', 5) gives -1: found only before start", () => {
+  expect(OurCommon.findStr("abcabc", "b", 5)).toStrictEqual(-1);
+});
+
+test("'abcabc'.find('c', -1) gives 5: negative start counts from the end", () => {
+  expect(OurCommon.findStr("abcabc", "c", -1)).toStrictEqual(5);
+});
+
+test("'abcabc'.find('a', -3) gives 3: negative start finds the later occurrence", () => {
+  expect(OurCommon.findStr("abcabc", "a", -3)).toStrictEqual(3);
+});
+
+test("'abcabc'.find('a', -10) gives 0: negative start before the beginning is clamped", () => {
+  expect(OurCommon.findStr("abcabc", "a", -10)).toStrictEqual(0);
+});
+
+test("'abcabc'.find('', 6) gives 6: empty sub at the end", () => {
+  expect(OurCommon.findStr("abcabc", "", 6)).toStrictEqual(6);
+});
+
+test("'abcabc'.find('', 7) gives -1: empty sub beyond the end gives -1", () => {
+  expect(OurCommon.findStr("abcabc", "", 7)).toStrictEqual(-1);
+});
+
+test("'abcabc'.find('c', 10) gives -1: start beyond the end gives -1", () => {
+  expect(OurCommon.findStr("abcabc", "c", 10)).toStrictEqual(-1);
+});
+
+test("''.find('') gives 0: empty sub in empty text", () => {
+  expect(OurCommon.findStr("", "")).toStrictEqual(0);
+});
+
+test("''.find('', 1) gives -1: empty sub beyond the end of empty text gives -1", () => {
+  expect(OurCommon.findStr("", "", 1)).toStrictEqual(-1);
+});
+
+test("''.find('x') gives -1: not found in empty text", () => {
+  expect(OurCommon.findStr("", "x")).toStrictEqual(-1);
+});
+
+test("'é-'.find('-') gives 1: after a character of two UTF-8 bytes", () => {
+  expect(OurCommon.findStr("é-", "-")).toStrictEqual(1);
+});
+
+test("'😀-'.find('-') gives 1: after a character beyond the Basic Multilingual Plane", () => {
+  expect(OurCommon.findStr("😀-", "-")).toStrictEqual(1);
+});
+
+test("'a😀b'.find('😀') gives 1: character beyond the Basic Multilingual Plane", () => {
+  expect(OurCommon.findStr("a😀b", "😀")).toStrictEqual(1);
+});
+
+test("'😀a😀a'.find('a', 2) gives 3: start after a character beyond ASCII", () => {
+  expect(OurCommon.findStr("😀a😀a", "a", 2)).toStrictEqual(3);
+});
+
+test("'😀a😀a'.find('😀', -2) gives 2: negative start on characters beyond ASCII", () => {
+  expect(OurCommon.findStr("😀a😀a", "😀", -2)).toStrictEqual(2);
+});
+
+test("'é😀'.find('', 3) gives -1: start beyond the end of characters beyond ASCII", () => {
+  expect(OurCommon.findStr("é😀", "", 3)).toStrictEqual(-1);
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.ts
new file mode 100644
index 000000000..42a5f9de4
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/common.ts
@@ -0,0 +1,380 @@
+/**
+ * Provide common functionality to be re-used across different tests
+ * such as reading of commonly-used environment variables.
+ */
+
+import * as fs from "fs";
+import * as path from "path";
+
+import * as OurTypes from "../src/types";
+import * as OurVerification from "../src/verification";
+import * as OurJsonization from "../src/jsonization";
+import { Path } from "../src/jsonization";
+
+// NOTE (mristin):
+// It is tedious to record manually all the expected error messages. Therefore we include this variable
+// to steer the automatic recording. We intentionally inter-twine the recording code with the test code
+// to keep them close to each other so that they are easier to maintain.
+export const RECORD_MODE_ENVIRONMENT_VARIABLE_NAME =
+  "DUMMY_TEST_RECORD_MODE";
+
+const RECORD_MODE_TEXT =
+  process.env[RECORD_MODE_ENVIRONMENT_VARIABLE_NAME]?.toLowerCase();
+export const RECORD_MODE: boolean =
+  RECORD_MODE_TEXT === "true" || RECORD_MODE_TEXT === "1" || RECORD_MODE_TEXT === "on";
+
+export const TEST_DATA_DIR = process.env[
+  "DUMMY_TEST_DATA_DIR"
+];
+if (TEST_DATA_DIR === null || TEST_DATA_DIR === undefined) {
+  throw new Error(
+    "The path to the test data directory is missing in the environment: " +
+      "DUMMY_TEST_DATA_DIR"
+  );
+}
+if (!fs.existsSync(TEST_DATA_DIR)) {
+  throw new Error(
+    "The path read from environment variable " +
+      "DUMMY_TEST_DATA_DIR does not exist: " +
+      TEST_DATA_DIR
+  );
+}
+if (!fs.lstatSync(TEST_DATA_DIR).isDirectory()) {
+  throw new Error(
+    "The path read from environment variable " +
+      "DUMMY_TEST_DATA_DIR is not a directory: " +
+      TEST_DATA_DIR
+  );
+}
+
+/**
+ * Read a JSON value from a file.
+ *
+ * @param aPath - to the file
+ * @returns a JSON value read from the file
+ */
+export function readJsonFromFileSync(aPath: string): OurJsonization.JsonValue {
+  const text = fs.readFileSync(aPath, "utf-8");
+  let jsonable: OurJsonization.JsonValue | null = null;
+  try {
+    jsonable = JSON.parse(text);
+  } catch (error) {
+    throw new Error(`Failed to parse JSON from: ${aPath}`);
+  }
+
+  if (jsonable === null) {
+    throw new Error(`Unexpected null value as JSON from: ${aPath}`);
+  }
+
+  return <OurJsonization.JsonValue>jsonable;
+}
+
+/**
+ * Find the first instance beneath and including the `container` which satisfies
+ * `condition`.
+ *
+ * @param container - where to search
+ * @param condition - that needs to be fulfilled
+ * @throws an {@link Error} if no instance could be found which satisfies
+ * `condition`
+ */
+export function mustFind(
+  container: OurTypes.Class,
+  condition: (instance: OurTypes.Class) => boolean
+) {
+  if (condition(container)) {
+    return container;
+  }
+
+  for (const instance of container.descend()) {
+    if (condition(instance)) {
+      return instance;
+    }
+  }
+
+  throw new Error("No instance could be found which satisfies the condition.");
+}
+
+/**
+ * Assert that there are no verification errors in the `iterable`.
+ *
+ * @param errors - iterable of verification errors
+ * @param aPath - to the file specifying the instance
+ * @throws an {@link Error} with an informative message
+ */
+export function assertNoVerificationErrors(
+  errors: IterableIterator<OurVerification.VerificationError>,
+  aPath: string
+): void {
+  const errorArray = errors instanceof Array ? errors : Array.from(errors);
+
+  if (errorArray.length !== 0) {
+    let message =
+      "Expected no errors when verifying the instance de-serialized " +
+      `from ${aPath}, but got ${errorArray.length} error(s):`;
+
+    for (let i = 0; i < errorArray.length; i++) {
+      const error = errorArray[i];
+
+      message += `\n\nError ${i + 1}:\n${error.path}: ${error.message}`;
+    }
+    throw new Error(message);
+  }
+}
+
+/**
+ * Assert that `errors` either correspond to the errors recorded to the disk,
+ * or re-record the errors, if {@link RECORD_MODE} is set.
+ *
+ * @param errors - iterable of verification errors on an instance
+ * @param aPath - to the instance
+ * @throws an {@link Error} if {@link RECORD_MODE} unset and the observed and
+ * recorded errors do not coincide
+ */
+export function assertExpectedOrRecordedVerificationErrors(
+  errors: IterableIterator<OurVerification.VerificationError>,
+  aPath: string
+): void {
+  const errorArray = errors instanceof Array ? errors : Array.from(errors);
+
+  if (errorArray.length === 0) {
+    throw new Error(
+      "Expected at least one verification error when " +
+        `verifying ${path}, but got none`
+    );
+  }
+
+  const got = errorArray.map((error) => `${error.path}: ${error.message}`).join(";\n");
+
+  const errorsPath = aPath + ".errors";
+  if (RECORD_MODE) {
+    fs.writeFileSync(errorsPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(errorsPath)) {
+      throw new Error(
+        `The file with the recorded verification errors does not ` +
+          `exist: ${errorsPath}; you probably want to set the environment ` +
+          `variable ${RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected = fs.readFileSync(errorsPath, "utf-8");
+    if (expected !== got) {
+      throw new Error(
+        `Expected verification errors from ${path}:\n` +
+          `${expected}\n, but got:\n${got}`
+      );
+    }
+  }
+}
+
+/**
+ * Represent the `instance` as a human-readable line of an iteration trace.
+ *
+ * @param instance - to leave a mark in the trace
+ * @returns the mark in the trace
+ */
+export function traceMark(instance: OurTypes.Class): string {
+  return instance.constructor.name;
+}
+
+/**
+ * Iterate over all the files beneath `directory` with the given `suffix` path.
+ *
+ * @param directory - to iterate through recursively
+ * @param suffix - expected suffix of the file name
+ */
+export function* findFilesBySuffixRecursively(
+  directory: string,
+  suffix: string
+): IterableIterator<string> {
+  for (const filename of fs.readdirSync(directory)) {
+    const pth = path.join(directory, filename);
+    const stat = fs.lstatSync(pth);
+    if (stat.isDirectory()) {
+      yield* findFilesBySuffixRecursively(pth, suffix);
+    } else {
+      if (filename.endsWith(suffix)) {
+        yield pth;
+      }
+    }
+  }
+}
+
+/**
+ * Iterate over all the immediate subdirectories `directory`.
+ *
+ * @param directory - to iterate through
+ */
+export function* findImmediateSubdirectories(
+  directory: string
+): IterableIterator<string> {
+  for (const filename of fs.readdirSync(directory)) {
+    const pth = path.join(directory, filename);
+    const stat = fs.lstatSync(pth);
+    if (stat.isDirectory()) {
+      yield pth;
+    }
+  }
+}
+
+/**
+ * Signal that two JSON-able structures are unequal.
+ */
+export class InequalityError {
+  /**
+   * Human-readable explanation of the error
+   */
+  readonly message: string;
+
+  /**
+   * Relative path to the erroneous value
+   */
+  readonly path: OurJsonization.Path;
+
+  constructor(message: string, path: OurJsonization.Path | null = null) {
+    this.message = message;
+    this.path = path ?? new Path();
+  }
+}
+
+/**
+ * Check that the `expected` JSON-able structure strictly equals `got`
+ * JSON-able structure.
+ *
+ * @param expected - JSON-able structure
+ * @param got - JSON-able structure
+ */
+export function checkJsonablesEqual(
+  expected: OurJsonization.JsonValue | null,
+  got: OurJsonization.JsonValue | null
+): OurJsonization.DeserializationError | null {
+  if (
+    expected === null ||
+    typeof expected === "boolean" ||
+    typeof expected === "number" ||
+    typeof expected === "string"
+  ) {
+    if (expected !== got) {
+      if (
+        got === null ||
+        typeof got === "boolean" ||
+        typeof got === "number" ||
+        typeof got === "string"
+      ) {
+        return new InequalityError(
+          `Expected ${JSON.stringify(expected)}, ` + `but got ${JSON.stringify(got)}`
+        );
+      } else {
+        return new InequalityError(
+          `Expected ${JSON.stringify(expected)}, ` +
+            `but got an instance of ${got.constructor.name}`
+        );
+      }
+    }
+  } else if (
+    typeof expected === "object" &&
+    typeof expected[Symbol.iterator] === "function"
+  ) {
+    if (typeof got !== "object") {
+      return new InequalityError(
+        `Expected an iterable, ` + `but got ${JSON.stringify(got)}`
+      );
+    }
+
+    if (typeof got[Symbol.iterator] !== "function") {
+      return new InequalityError(
+        `Expected an iterable, ` + `but got an instance of ${got.constructor.name}`
+      );
+    }
+
+    const expectedIt = <Iterator<OurJsonization.JsonValue>>expected[Symbol.iterator]();
+
+    const gotIt = <Iterator<OurJsonization.JsonValue>>got[Symbol.iterator]();
+
+    let i = 0;
+    // eslint-disable-next-line no-constant-condition
+    while (true) {
+      const expectedResult = expectedIt.next();
+      const gotResult = gotIt.next();
+
+      if (expectedResult.done && gotResult.done) {
+        break;
+      }
+
+      if (expectedResult.done && !gotResult.done) {
+        return new InequalityError(
+          `Expected an iterable with ${i + 1} items, ` +
+            `but got an iterable with more items`
+        );
+      }
+
+      if (!expectedResult.done && gotResult.done) {
+        return new InequalityError(
+          `Expected an iterable with more than ${i + 1} item(s), ` +
+            `but got an iterable with only ${i + 1} item(s)`
+        );
+      }
+
+      const expectedItem = expectedResult.value;
+      const gotItem = expectedResult.value;
+
+      const error = checkJsonablesEqual(expectedItem, gotItem);
+      if (error !== null) {
+        error.path.prepend(
+          new OurJsonization.IndexSegment(<OurJsonization.JsonArray>expected, i)
+        );
+        return error;
+      }
+
+      i++;
+    }
+  } else if (typeof expected === "object") {
+    const expectedKeys = new Set<string>(
+      Object.keys(expected).filter((key) =>
+        Object.prototype.hasOwnProperty.call(expected, key)
+      )
+    );
+
+    const gotKeys = new Set<string>(
+      Object.keys(expected).filter((key) =>
+        Object.prototype.hasOwnProperty.call(got, key)
+      )
+    );
+
+    for (const key of expectedKeys) {
+      if (!gotKeys.has(key)) {
+        return new InequalityError(
+          `Expected an object with key ${JSON.stringify(key)}, ` +
+            `but got an object without that key`
+        );
+      }
+    }
+
+    for (const key of gotKeys) {
+      if (!expectedKeys.has(key)) {
+        return new InequalityError(
+          `Expected an object without the key ${JSON.stringify(key)}, ` +
+            `but got an object with that key`
+        );
+      }
+    }
+
+    for (const key of expectedKeys) {
+      const expectedValue = expected[key];
+      const gotValue = got[key];
+
+      const error = checkJsonablesEqual(expectedValue, gotValue);
+      if (error !== null) {
+        error.path.prepend(
+          new OurJsonization.PropertySegment(<OurJsonization.JsonObject>expected, key)
+        );
+        return error;
+      }
+    }
+  } else {
+    throw new Error(`Unexpected expected value: ${expected}`);
+  }
+
+  return null;
+}
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonJsonization.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonJsonization.ts
new file mode 100644
index 000000000..fb7ed37c2
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonJsonization.ts
@@ -0,0 +1,272 @@
+/**
+ * Provide functions for loading generated examples of model instances.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as path from "path";
+
+import * as OurTypes from "../src/types";
+import * as OurJsonization from "../src/jsonization";
+
+import * as TestCommon from "./common";
+
+/**
+ * Load a maximal example of {@link types.SomeItem} from
+ * the test data directory.
+ */
+export function loadMaximalSomeItem(
+): OurTypes.SomeItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "SomeItem",
+    "maximal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSomeItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SomeItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal example of {@link types.SomeItem} from
+ * the test data directory.
+ */
+export function loadMinimalSomeItem(
+): OurTypes.SomeItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "SomeItem",
+    "minimal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSomeItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SomeItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal example of {@link types.SpecialItem} from
+ * the test data directory.
+ */
+export function loadMaximalSpecialItem(
+): OurTypes.SpecialItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "SpecialItem",
+    "maximal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.specialItemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSpecialItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SpecialItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal example of {@link types.SpecialItem} from
+ * the test data directory.
+ */
+export function loadMinimalSpecialItem(
+): OurTypes.SpecialItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "SpecialItem",
+    "minimal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.specialItemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSpecialItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SpecialItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal example of {@link types.Container} from
+ * the test data directory.
+ */
+export function loadMaximalContainer(
+): OurTypes.Container {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "Container",
+    "maximal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.containerFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asContainer(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Container in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal example of {@link types.Container} from
+ * the test data directory.
+ */
+export function loadMinimalContainer(
+): OurTypes.Container {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "Container",
+    "minimal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.containerFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asContainer(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Container in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal example of {@link types.Wrapper} from
+ * the test data directory.
+ */
+export function loadMaximalWrapper(
+): OurTypes.Wrapper {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "Wrapper",
+    "maximal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.wrapperFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asWrapper(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Wrapper in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal example of {@link types.Wrapper} from
+ * the test data directory.
+ */
+export function loadMinimalWrapper(
+): OurTypes.Wrapper {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Json",
+    "Expected",
+    "Wrapper",
+    "minimal.json"
+  );
+
+  const jsonable = TestCommon.readJsonFromFileSync(aPath);
+
+  const instanceOrError = OurJsonization.wrapperFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asWrapper(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Wrapper in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonXmlization.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonXmlization.ts
new file mode 100644
index 000000000..3935e75ad
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/commonXmlization.ts
@@ -0,0 +1,273 @@
+/**
+ * Provide functions for loading generated XML examples of model instances.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as fs from "fs";
+import * as path from "path";
+
+import * as OurTypes from "../src/types";
+import * as OurXmlization from "../src/xmlization";
+
+import * as TestCommon from "./common";
+
+/**
+ * Load a maximal XML example of {@link types.SomeItem}
+ * from the test data directory.
+ */
+export function loadMaximalSomeItem(
+): OurTypes.SomeItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "someItem",
+    "maximal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSomeItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SomeItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal XML example of {@link types.SomeItem}
+ * from the test data directory.
+ */
+export function loadMinimalSomeItem(
+): OurTypes.SomeItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "someItem",
+    "minimal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSomeItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SomeItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal XML example of {@link types.SpecialItem}
+ * from the test data directory.
+ */
+export function loadMaximalSpecialItem(
+): OurTypes.SpecialItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "specialItem",
+    "maximal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSpecialItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SpecialItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal XML example of {@link types.SpecialItem}
+ * from the test data directory.
+ */
+export function loadMinimalSpecialItem(
+): OurTypes.SpecialItem {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "specialItem",
+    "minimal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asSpecialItem(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of SpecialItem in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal XML example of {@link types.Container}
+ * from the test data directory.
+ */
+export function loadMaximalContainer(
+): OurTypes.Container {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "container",
+    "maximal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asContainer(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Container in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal XML example of {@link types.Container}
+ * from the test data directory.
+ */
+export function loadMinimalContainer(
+): OurTypes.Container {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "container",
+    "minimal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asContainer(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Container in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a maximal XML example of {@link types.Wrapper}
+ * from the test data directory.
+ */
+export function loadMaximalWrapper(
+): OurTypes.Wrapper {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "wrapper",
+    "maximal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asWrapper(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Wrapper in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+/**
+ * Load a minimal XML example of {@link types.Wrapper}
+ * from the test data directory.
+ */
+export function loadMinimalWrapper(
+): OurTypes.Wrapper {
+  const aPath = path.join(
+    TestCommon.TEST_DATA_DIR,
+    "Xml",
+    "Expected",
+    "wrapper",
+    "minimal.xml"
+  );
+
+  const text = fs.readFileSync(aPath, "utf-8");
+
+  const instanceOrError = OurXmlization.fromXmlString(
+    text
+  );
+  expect(instanceOrError.error).toBeNull();
+  const instance = instanceOrError.mustValue();
+
+  const casted = OurTypes.asWrapper(instance);
+  if (casted === null) {
+    throw new Error(
+      `Expected instance of Wrapper in ${aPath}, ` +
+      `but got: ${typeof instance}`
+    );
+  }
+  return casted;
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.common.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.common.spec.ts
new file mode 100644
index 000000000..27d3621cb
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.common.spec.ts
@@ -0,0 +1,31 @@
+/**
+ * Execute all common JSONization loader helpers once.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as TestCommonJsonization from "./commonJsonization";
+
+test("commonJsonization loaders for SomeItem", () => {
+  expect(TestCommonJsonization.loadMinimalSomeItem()).not.toBeNull();
+  expect(TestCommonJsonization.loadMaximalSomeItem()).not.toBeNull();
+});
+
+test("commonJsonization loaders for SpecialItem", () => {
+  expect(TestCommonJsonization.loadMinimalSpecialItem()).not.toBeNull();
+  expect(TestCommonJsonization.loadMaximalSpecialItem()).not.toBeNull();
+});
+
+test("commonJsonization loaders for Container", () => {
+  expect(TestCommonJsonization.loadMinimalContainer()).not.toBeNull();
+  expect(TestCommonJsonization.loadMaximalContainer()).not.toBeNull();
+});
+
+test("commonJsonization loaders for Wrapper", () => {
+  expect(TestCommonJsonization.loadMinimalWrapper()).not.toBeNull();
+  expect(TestCommonJsonization.loadMaximalWrapper()).not.toBeNull();
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.concreteClasses.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.concreteClasses.spec.ts
new file mode 100644
index 000000000..c3c9159fa
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.concreteClasses.spec.ts
@@ -0,0 +1,764 @@
+/**
+ * Test JSON de/serialization of concrete classes.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as fs from "fs";
+import * as path from "path";
+
+import * as OurJsonization from "../src/jsonization";
+import * as OurTypes from "../src/types";
+import * as OurVerification from "../src/verification";
+
+import * as TestCommon from "./common";
+
+/**
+ * Assert that the result of the chain JSON → de-serialize → object → serialize → JSON
+ * gives the input.
+ */
+function assertSerializeDeserializeEqualsOriginal(
+  originalJsonable: OurJsonization.JsonValue,
+  instance: OurTypes.Class,
+  aPath: string
+): void {
+  let jsonable: OurJsonization.JsonValue | null = null;
+  try {
+    jsonable = OurJsonization.toJsonable(instance);
+  } catch (error) {
+    throw new Error(
+      "Expected no exception during JSON serialization " +
+      `of an instance of ${instance.constructor.name} from ${aPath}, ` +
+      `but got: ${error}`
+    );
+  }
+
+  const inequalityError = TestCommon.checkJsonablesEqual(
+    originalJsonable,
+    jsonable
+  );
+  if (inequalityError !== null) {
+    throw new Error(
+      `The original JSON from ${aPath} is unequal the serialized JSON: ` +
+      `${inequalityError.path}: ${inequalityError.message}`
+    );
+  }
+}
+
+/**
+ * Assert that the deserialization error equals the expected golden one,
+ * or, if {@link common.RECORD_MODE} set, re-record the expected error.
+ *
+ * @param error - obtained error during the de-serialization
+ * @param aPath - to the JSON file which caused the de-serialization error
+ * @throws an {@link Error} if assertion fails
+ */
+function assertDeserializationErrorEqualsExpectedOrRecord(
+  error: OurJsonization.DeserializationError,
+  aPath: string
+): void {
+  const errorPath = aPath + ".error";
+  const got = `${error.path}: ${error.message}\n`;
+
+  if (TestCommon.RECORD_MODE) {
+    fs.writeFileSync(errorPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(errorPath)) {
+      throw new Error(
+        `The file with the recorded deserialization error does ` +
+        `not exist: ${errorPath}; you probably want to set ` +
+        `the environment variable ${TestCommon.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected =
+      fs.readFileSync(errorPath, "utf-8")
+      .replace(/\r\n/g, "\n");
+    if (expected !== got) {
+      throw new Error(
+        `Expected the error:\n${JSON.stringify(expected)}\n, ` +
+        `but got:\n${JSON.stringify(got)}\n` +
+        `when de-serializing from ${aPath}`
+      );
+    }
+  }
+}
+
+/**
+ * Assert that the obtained verification errors equal the expected verification errors,
+ * or, if {@link common.RECORD_MODE} set, re-record the expected errors.
+ *
+ * @param errors - obtained verification errors
+ * @param aPath - to the JSON file which caused the verification errors
+ * @throws an {@link Error} if assertion fails
+ */
+function assertVerificationErrorsEqualExpectedOrRecord(
+  errors: Array<OurVerification.VerificationError>,
+  aPath: string
+): void {
+  const errorsPath = aPath + ".errors";
+
+  const lines = new Array<string>();
+  for (const error of errors) {
+    lines.push(`${error.path}: ${error.message}`);
+  }
+  // NOTE (mristin):
+  // We add a new line for POSIX systems which prefer a new line
+  // at the end of the file.
+  lines.push("");
+  const got = lines.join("\n");
+
+  if (TestCommon.RECORD_MODE) {
+    fs.writeFileSync(errorsPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(errorsPath)) {
+      throw new Error(
+        `The file with the recorded verification errors ` +
+        `does not exist: ${errorsPath}; you probably want to set the environment ` +
+        `variable ${TestCommon.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected =
+      fs.readFileSync(errorsPath, "utf-8")
+      .replace(/\r\n/g, "\n");
+    if (expected !== got) {
+      throw new Error(
+        `Expected the error(s):\n${JSON.stringify(expected)}\n, ` +
+        `but got:\n${JSON.stringify(got)}\n` +
+        `when verifying ${aPath}`
+      );
+    }
+  }
+}
+
+test("SomeItem round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Expected",
+        "SomeItem"
+      ),
+      ".json"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+    const instanceOrError = OurJsonization.someItemFromJsonable(
+      jsonable
+    );
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(instance), pth);
+
+    assertSerializeDeserializeEqualsOriginal(
+      jsonable,
+      instance,
+      pth
+    );
+  }
+});
+
+test("SomeItem deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    // NOTE (mristin):
+    // Unlike other SDKs, we can not be really sure what additional properties
+    // JavaScript might bring about. Therefore, we leave out the tests with
+    // the validation of additional properties.
+    if (path.basename(causeDir) == "UnexpectedAdditionalProperty") {
+      continue;
+    }
+
+    const clsDir = path.join(
+      causeDir,
+      "SomeItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.someItemFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error === null) {
+        throw new Error(`Expected a de-serialization error for ${pth}, but got none`);
+      }
+
+      assertDeserializationErrorEqualsExpectedOrRecord(
+        instanceOrError.error,
+        pth
+      );
+    }
+  }
+});
+
+test("SomeItem verification fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Invalid"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "SomeItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.someItemFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error !== null) {
+        throw new Error(
+          `Expected no de-serialization error for ${pth}, ` +
+          `but got: ${instanceOrError.error.message}: ${instanceOrError.error.path}`
+        );
+      }
+
+      const instance = instanceOrError.mustValue();
+
+      const verificationErrors = Array.from(OurVerification.verify(instance));
+      assertVerificationErrorsEqualExpectedOrRecord(
+        verificationErrors,
+        pth
+      );
+    }
+  }
+});
+
+test("SpecialItem round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Expected",
+        "SpecialItem"
+      ),
+      ".json"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+    const instanceOrError = OurJsonization.specialItemFromJsonable(
+      jsonable
+    );
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(instance), pth);
+
+    assertSerializeDeserializeEqualsOriginal(
+      jsonable,
+      instance,
+      pth
+    );
+  }
+});
+
+test("SpecialItem deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    // NOTE (mristin):
+    // Unlike other SDKs, we can not be really sure what additional properties
+    // JavaScript might bring about. Therefore, we leave out the tests with
+    // the validation of additional properties.
+    if (path.basename(causeDir) == "UnexpectedAdditionalProperty") {
+      continue;
+    }
+
+    const clsDir = path.join(
+      causeDir,
+      "SpecialItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.specialItemFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error === null) {
+        throw new Error(`Expected a de-serialization error for ${pth}, but got none`);
+      }
+
+      assertDeserializationErrorEqualsExpectedOrRecord(
+        instanceOrError.error,
+        pth
+      );
+    }
+  }
+});
+
+test("SpecialItem verification fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Invalid"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "SpecialItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.specialItemFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error !== null) {
+        throw new Error(
+          `Expected no de-serialization error for ${pth}, ` +
+          `but got: ${instanceOrError.error.message}: ${instanceOrError.error.path}`
+        );
+      }
+
+      const instance = instanceOrError.mustValue();
+
+      const verificationErrors = Array.from(OurVerification.verify(instance));
+      assertVerificationErrorsEqualExpectedOrRecord(
+        verificationErrors,
+        pth
+      );
+    }
+  }
+});
+
+test("Container round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Expected",
+        "Container"
+      ),
+      ".json"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+    const instanceOrError = OurJsonization.containerFromJsonable(
+      jsonable
+    );
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(instance), pth);
+
+    assertSerializeDeserializeEqualsOriginal(
+      jsonable,
+      instance,
+      pth
+    );
+  }
+});
+
+test("Container deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    // NOTE (mristin):
+    // Unlike other SDKs, we can not be really sure what additional properties
+    // JavaScript might bring about. Therefore, we leave out the tests with
+    // the validation of additional properties.
+    if (path.basename(causeDir) == "UnexpectedAdditionalProperty") {
+      continue;
+    }
+
+    const clsDir = path.join(
+      causeDir,
+      "Container"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.containerFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error === null) {
+        throw new Error(`Expected a de-serialization error for ${pth}, but got none`);
+      }
+
+      assertDeserializationErrorEqualsExpectedOrRecord(
+        instanceOrError.error,
+        pth
+      );
+    }
+  }
+});
+
+test("Container verification fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Invalid"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "Container"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.containerFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error !== null) {
+        throw new Error(
+          `Expected no de-serialization error for ${pth}, ` +
+          `but got: ${instanceOrError.error.message}: ${instanceOrError.error.path}`
+        );
+      }
+
+      const instance = instanceOrError.mustValue();
+
+      const verificationErrors = Array.from(OurVerification.verify(instance));
+      assertVerificationErrorsEqualExpectedOrRecord(
+        verificationErrors,
+        pth
+      );
+    }
+  }
+});
+
+test("Wrapper round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Expected",
+        "Wrapper"
+      ),
+      ".json"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+    const instanceOrError = OurJsonization.wrapperFromJsonable(
+      jsonable
+    );
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(instance), pth);
+
+    assertSerializeDeserializeEqualsOriginal(
+      jsonable,
+      instance,
+      pth
+    );
+  }
+});
+
+test("Wrapper deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    // NOTE (mristin):
+    // Unlike other SDKs, we can not be really sure what additional properties
+    // JavaScript might bring about. Therefore, we leave out the tests with
+    // the validation of additional properties.
+    if (path.basename(causeDir) == "UnexpectedAdditionalProperty") {
+      continue;
+    }
+
+    const clsDir = path.join(
+      causeDir,
+      "Wrapper"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.wrapperFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error === null) {
+        throw new Error(`Expected a de-serialization error for ${pth}, but got none`);
+      }
+
+      assertDeserializationErrorEqualsExpectedOrRecord(
+        instanceOrError.error,
+        pth
+      );
+    }
+  }
+});
+
+test("Wrapper verification fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Unexpected",
+        "Invalid"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "Wrapper"
+    );
+    if (!fs.existsSync(clsDir)) {
+      // NOTE (mristin):
+      // Some classes indeed lack the invalid examples.
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".json"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const jsonable = TestCommon.readJsonFromFileSync(pth);
+
+      const instanceOrError = OurJsonization.wrapperFromJsonable(
+        jsonable
+      );
+      if (instanceOrError.error !== null) {
+        throw new Error(
+          `Expected no de-serialization error for ${pth}, ` +
+          `but got: ${instanceOrError.error.message}: ${instanceOrError.error.path}`
+        );
+      }
+
+      const instance = instanceOrError.mustValue();
+
+      const verificationErrors = Array.from(OurVerification.verify(instance));
+      assertVerificationErrorsEqualExpectedOrRecord(
+        verificationErrors,
+        pth
+      );
+    }
+  }
+});
+
+/**
+ * Load the first recorded example of the `modelType`.
+ */
+function loadTheFirstExpected(modelType: string): OurJsonization.JsonValue {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Json",
+        "Expected",
+        modelType
+      ),
+      ".json"
+    )
+  );
+  pths.sort();
+
+  if (pths.length === 0) {
+    throw new Error(
+      `Expected at least one recorded example of ${modelType}, but got none`
+    );
+  }
+
+  return TestCommon.readJsonFromFileSync(pths[0]);
+}
+
+test(
+  "Special_item serialization fails on an integer outside the range representable in JSON "
+  + "at .level",
+  () => {
+    for (const value of [9007199254740992, -9007199254740992]) {
+      const instance = OurJsonization.specialItemFromJsonable(
+        loadTheFirstExpected("SpecialItem")
+      ).mustValue();
+
+      instance.level = value;
+
+      let caught: unknown = null;
+      try {
+        OurJsonization.toJsonable(instance);
+      } catch (error) {
+        caught = error;
+      }
+
+      if (!(caught instanceof OurJsonization.SerializationError)) {
+        throw new Error(
+          `Expected a SerializationError, but got: ${caught}`
+        );
+      }
+
+      expect(caught.path).toStrictEqual(".level");
+    }
+  }
+);
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.enums.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.enums.spec.ts
new file mode 100644
index 000000000..4c4901aa1
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.enums.spec.ts
@@ -0,0 +1,12 @@
+/**
+ * Test JSON de/serialization of enumeration literals.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurJsonization from "../src/jsonization";
+import * as OurTypes from "../src/types";
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.interfaces.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.interfaces.spec.ts
new file mode 100644
index 000000000..d48f514f0
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.interfaces.spec.ts
@@ -0,0 +1,155 @@
+/**
+ * Test JSON de/serialization of interfaces.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurJsonization from "../src/jsonization";
+import * as TestCommon from "./common";
+import * as TestCommonJsonization from "./commonJsonization";
+
+test(
+  "IItem round-trip " +
+  "starting from SomeItem OK",
+  () => {
+  const instance = TestCommonJsonization.loadMinimalSomeItem();
+
+  const jsonable = OurJsonization.toJsonable(instance);
+
+  const anotherInstanceOrError = OurJsonization.itemFromJsonable(
+    jsonable
+  );
+  expect(anotherInstanceOrError.error).toBeNull();
+  const anotherInstance = anotherInstanceOrError.mustValue();
+
+  const anotherJsonable = OurJsonization.toJsonable(anotherInstance);
+
+  const inequalityError = TestCommon.checkJsonablesEqual(
+    jsonable,
+    anotherJsonable
+  );
+  if (inequalityError !== null) {
+    throw new Error(
+      "The minimal example of IItem " +
+      "as an instance of SomeItem serialized " +
+      "to JSON, then de-serialized and serialized again does not match " +
+      `the first JSON: ${inequalityError.path}: ${inequalityError.message}`
+    );
+  }
+});
+
+test(
+  "IItem round-trip " +
+  "starting from SpecialItem OK",
+  () => {
+  const instance = TestCommonJsonization.loadMinimalSpecialItem();
+
+  const jsonable = OurJsonization.toJsonable(instance);
+
+  const anotherInstanceOrError = OurJsonization.itemFromJsonable(
+    jsonable
+  );
+  expect(anotherInstanceOrError.error).toBeNull();
+  const anotherInstance = anotherInstanceOrError.mustValue();
+
+  const anotherJsonable = OurJsonization.toJsonable(anotherInstance);
+
+  const inequalityError = TestCommon.checkJsonablesEqual(
+    jsonable,
+    anotherJsonable
+  );
+  if (inequalityError !== null) {
+    throw new Error(
+      "The minimal example of IItem " +
+      "as an instance of SpecialItem serialized " +
+      "to JSON, then de-serialized and serialized again does not match " +
+      `the first JSON: ${inequalityError.path}: ${inequalityError.message}`
+    );
+  }
+});
+
+test("IItem deserialization fail", () => {
+  const jsonable = "This is not a IItem.";
+
+  const instanceOrError = OurJsonization.itemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error.message).toStrictEqual(
+    "Expected a JSON object, but got: string"
+  );
+});
+
+test(
+  "ISomeItem round-trip " +
+  "starting from SpecialItem OK",
+  () => {
+  const instance = TestCommonJsonization.loadMinimalSpecialItem();
+
+  const jsonable = OurJsonization.toJsonable(instance);
+
+  const anotherInstanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+  expect(anotherInstanceOrError.error).toBeNull();
+  const anotherInstance = anotherInstanceOrError.mustValue();
+
+  const anotherJsonable = OurJsonization.toJsonable(anotherInstance);
+
+  const inequalityError = TestCommon.checkJsonablesEqual(
+    jsonable,
+    anotherJsonable
+  );
+  if (inequalityError !== null) {
+    throw new Error(
+      "The minimal example of ISomeItem " +
+      "as an instance of SpecialItem serialized " +
+      "to JSON, then de-serialized and serialized again does not match " +
+      `the first JSON: ${inequalityError.path}: ${inequalityError.message}`
+    );
+  }
+});
+
+test(
+  "ISomeItem round-trip " +
+  "starting from SomeItem OK",
+  () => {
+  const instance = TestCommonJsonization.loadMinimalSomeItem();
+
+  const jsonable = OurJsonization.toJsonable(instance);
+
+  const anotherInstanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+  expect(anotherInstanceOrError.error).toBeNull();
+  const anotherInstance = anotherInstanceOrError.mustValue();
+
+  const anotherJsonable = OurJsonization.toJsonable(anotherInstance);
+
+  const inequalityError = TestCommon.checkJsonablesEqual(
+    jsonable,
+    anotherJsonable
+  );
+  if (inequalityError !== null) {
+    throw new Error(
+      "The minimal example of ISomeItem " +
+      "as an instance of SomeItem serialized " +
+      "to JSON, then de-serialized and serialized again does not match " +
+      `the first JSON: ${inequalityError.path}: ${inequalityError.message}`
+    );
+  }
+});
+
+test("ISomeItem deserialization fail", () => {
+  const jsonable = "This is not a ISomeItem.";
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+  expect(instanceOrError.error.message).toStrictEqual(
+    "Expected a JSON object, but got: string"
+  );
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.negative.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.negative.spec.ts
new file mode 100644
index 000000000..0f84adc23
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/jsonization.negative.spec.ts
@@ -0,0 +1,77 @@
+/**
+ * Test failure modes in JSON parsing to exercise defensive branches.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as path from "path";
+
+import * as OurJsonization from "../src/jsonization";
+
+import * as TestCommon from "./common";
+
+function readExpectedJson(
+    classJsonName: string,
+    fileName: "minimal.json" | "maximal.json"
+): OurJsonization.JsonValue {
+  const pth = path.join(TestCommon.TEST_DATA_DIR, "Json", "Expected", classJsonName, fileName);
+  return TestCommon.readJsonFromFileSync(pth);
+}
+
+function mustBeJsonObject(jsonable: OurJsonization.JsonValue): OurJsonization.JsonObject {
+  if (
+    typeof jsonable !== "object" ||
+    jsonable === null ||
+    typeof jsonable[Symbol.iterator] === "function"
+  ) {
+    throw new Error(`Expected a JSON object, but got: ${JSON.stringify(jsonable)}`);
+  }
+
+  return <OurJsonization.JsonObject>jsonable;
+}
+
+test("SomeItem deserialization fails on non-object", () => {
+  const jsonable = "This is not a JSON object.";
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonable
+  );
+
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test("SomeItem deserialization fails with missing required property", () => {
+  const jsonable = readExpectedJson(
+    "SomeItem",
+    "minimal.json"
+  );
+
+  const jsonObject = { ...mustBeJsonObject(jsonable) };
+  delete jsonObject["name"];
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonObject
+  );
+
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test("SomeItem deserialization fails with property type mismatch", () => {
+  const jsonable = readExpectedJson(
+    "SomeItem",
+    "minimal.json"
+  );
+
+  const jsonObject = { ...mustBeJsonObject(jsonable) };
+  jsonObject["name"] = { definitely: "unexpected-object" };
+
+  const instanceOrError = OurJsonization.someItemFromJsonable(
+    jsonObject
+  );
+
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/stringification.enums.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/stringification.enums.spec.ts
new file mode 100644
index 000000000..4f812f49c
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/stringification.enums.spec.ts
@@ -0,0 +1,12 @@
+/**
+ * Test string de/serialization of enumeration literals.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurStringification from "../src/stringification";
+import * as OurTypes from "../src/types";
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.casts.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.casts.spec.ts
new file mode 100644
index 000000000..28a4f6e4d
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.casts.spec.ts
@@ -0,0 +1,172 @@
+/**
+ * Test `as*` and `is*` functions.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "../src/types";
+import * as TestCommonJsonization from "./commonJsonization";
+
+test("casts over an instance of SomeItem", () => {
+  const theSomeItem =
+    TestCommonJsonization.loadMinimalSomeItem();
+
+  expect(
+    OurTypes.isItem(theSomeItem)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asItem(theSomeItem)
+  ).toStrictEqual(theSomeItem);
+
+  expect(
+    OurTypes.isSomeItem(theSomeItem)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asSomeItem(theSomeItem)
+  ).toStrictEqual(theSomeItem);
+
+  expect(
+    OurTypes.isSpecialItem(theSomeItem)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asSpecialItem(theSomeItem)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isContainer(theSomeItem)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asContainer(theSomeItem)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isWrapper(theSomeItem)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asWrapper(theSomeItem)
+  ).toBeNull();
+});
+
+test("casts over an instance of SpecialItem", () => {
+  const theSpecialItem =
+    TestCommonJsonization.loadMinimalSpecialItem();
+
+  expect(
+    OurTypes.isItem(theSpecialItem)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asItem(theSpecialItem)
+  ).toStrictEqual(theSpecialItem);
+
+  expect(
+    OurTypes.isSomeItem(theSpecialItem)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asSomeItem(theSpecialItem)
+  ).toStrictEqual(theSpecialItem);
+
+  expect(
+    OurTypes.isSpecialItem(theSpecialItem)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asSpecialItem(theSpecialItem)
+  ).toStrictEqual(theSpecialItem);
+
+  expect(
+    OurTypes.isContainer(theSpecialItem)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asContainer(theSpecialItem)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isWrapper(theSpecialItem)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asWrapper(theSpecialItem)
+  ).toBeNull();
+});
+
+test("casts over an instance of Container", () => {
+  const theContainer =
+    TestCommonJsonization.loadMinimalContainer();
+
+  expect(
+    OurTypes.isItem(theContainer)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asItem(theContainer)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isSomeItem(theContainer)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asSomeItem(theContainer)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isSpecialItem(theContainer)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asSpecialItem(theContainer)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isContainer(theContainer)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asContainer(theContainer)
+  ).toStrictEqual(theContainer);
+
+  expect(
+    OurTypes.isWrapper(theContainer)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asWrapper(theContainer)
+  ).toBeNull();
+});
+
+test("casts over an instance of Wrapper", () => {
+  const theWrapper =
+    TestCommonJsonization.loadMinimalWrapper();
+
+  expect(
+    OurTypes.isItem(theWrapper)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asItem(theWrapper)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isSomeItem(theWrapper)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asSomeItem(theWrapper)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isSpecialItem(theWrapper)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asSpecialItem(theWrapper)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isContainer(theWrapper)
+  ).toStrictEqual(false);
+  expect(
+    OurTypes.asContainer(theWrapper)
+  ).toBeNull();
+
+  expect(
+    OurTypes.isWrapper(theWrapper)
+  ).toStrictEqual(true);
+  expect(
+    OurTypes.asWrapper(theWrapper)
+  ).toStrictEqual(theWrapper);
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendAndPassThroughVisitor.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendAndPassThroughVisitor.spec.ts
new file mode 100644
index 000000000..8ddeb1cc4
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendAndPassThroughVisitor.spec.ts
@@ -0,0 +1,178 @@
+/**
+ * Test `descend*` functions and `PassThroughVisitor`.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as path from "path";
+import * as fs from "fs";
+
+import * as OurTypes from "../src/types";
+import * as TestCommon from "./common";
+import * as TestCommonJsonization from "./commonJsonization";
+
+/**
+ * Record a human-readable trace of a descent over an object tree.
+ */
+class TracingVisitor extends OurTypes.PassThroughVisitor {
+  readonly log = new Array<string>();
+
+  visit(that: OurTypes.Class) {
+    this.log.push(TestCommon.traceMark(that));
+    super.visit(that);
+  }
+}
+
+/**
+ * Expect that the trace from {@link types.Class.descend} and
+ * {@link TracingVisitor} are equal.
+ *
+ * @param instance - to be descended through
+ * @throws an {@link Error} if the two traces are not equal
+ */
+function expectDescendAndPassThroughVisitorSame(
+  instance: OurTypes.Class
+): void {
+  const traceFromDescend = new Array<string>();
+  for (const subInstance of instance.descend()) {
+    traceFromDescend.push(TestCommon.traceMark(subInstance));
+  }
+
+  const visitor = new TracingVisitor();
+  visitor.visit(instance);
+  const traceFromVisitor = visitor.log;
+
+  expect(traceFromVisitor.length).toBeGreaterThan(0);
+  expect(TestCommon.traceMark(instance)).toStrictEqual(traceFromVisitor[0]);
+
+  traceFromVisitor.shift();
+
+  expect(traceFromVisitor).toStrictEqual(traceFromDescend);
+}
+
+/**
+ * Compare the trace against the golden one from the test data,
+ * or re-record the trace if {@link common.RECORD_MODE}.
+ *
+ * @param instance - to be traced
+ * @param expectedPath - path to the golden trace
+ */
+function compareOrRecordTrace(
+  instance: OurTypes.Class,
+  expectedPath: string
+) {
+  const lines = new Array<string>();
+  for (const descendant of instance.descend()) {
+    lines.push(TestCommon.traceMark(descendant));
+  }
+  // NOTE (mristin):
+  // We add a new line for POSIX systems which prefer a new line
+  // at the end of the file.
+  lines.push("");
+  const got = lines.join("\n");
+
+  if (TestCommon.RECORD_MODE) {
+    const parent = path.dirname(expectedPath);
+    if (!fs.existsSync(parent)) {
+      fs.mkdirSync(parent, {recursive: true});
+    }
+    fs.writeFileSync(expectedPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(expectedPath)) {
+      throw new Error(
+        `The file with the recorded trace does not exist: ${expectedPath}; ` +
+        `you probably want to set the environment ` +
+        `variable ${TestCommon.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected =
+      fs.readFileSync(expectedPath, "utf-8")
+      .replace(/\r\n/g, "\n");
+    expect(got).toStrictEqual(expected);
+  }
+}
+
+test("descend of SomeItem", () => {
+  const instance = TestCommonJsonization.loadMaximalSomeItem();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descend",
+      "SomeItem",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descend against PassThroughVisitor", () => {
+  const instance = TestCommonJsonization.loadMaximalSomeItem();
+
+  expectDescendAndPassThroughVisitorSame(instance);
+});
+
+test("descend of SpecialItem", () => {
+  const instance = TestCommonJsonization.loadMaximalSpecialItem();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descend",
+      "SpecialItem",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descend against PassThroughVisitor", () => {
+  const instance = TestCommonJsonization.loadMaximalSpecialItem();
+
+  expectDescendAndPassThroughVisitorSame(instance);
+});
+
+test("descend of Container", () => {
+  const instance = TestCommonJsonization.loadMaximalContainer();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descend",
+      "Container",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descend against PassThroughVisitor", () => {
+  const instance = TestCommonJsonization.loadMaximalContainer();
+
+  expectDescendAndPassThroughVisitorSame(instance);
+});
+
+test("descend of Wrapper", () => {
+  const instance = TestCommonJsonization.loadMaximalWrapper();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descend",
+      "Wrapper",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descend against PassThroughVisitor", () => {
+  const instance = TestCommonJsonization.loadMaximalWrapper();
+
+  expectDescendAndPassThroughVisitorSame(instance);
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendOnce.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendOnce.spec.ts
new file mode 100644
index 000000000..e5e3a3211
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.descendOnce.spec.ts
@@ -0,0 +1,115 @@
+/**
+ * Test `descendOnce*` functions.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as path from "path";
+import * as fs from "fs";
+
+import * as OurTypes from "../src/types";
+import * as TestCommon from "./common";
+import * as TestCommonJsonization from "./commonJsonization";
+
+/**
+ * Compare the trace against the golden one from the test data,
+ * or re-record the trace if {@link common.RECORD_MODE}.
+ *
+ * @param instance - to be traced
+ * @param expectedPath - path to the golden trace
+ */
+function compareOrRecordTrace(
+  instance: OurTypes.Class,
+  expectedPath: string
+) {
+  const lines = new Array<string>();
+  for (const descendant of instance.descendOnce()) {
+    lines.push(TestCommon.traceMark(descendant));
+  }
+  // NOTE (mristin):
+  // We add a new line for POSIX systems which prefer a new line
+  // at the end of the file.
+  lines.push("");
+  const got = lines.join("\n");
+
+  if (TestCommon.RECORD_MODE) {
+    const parent = path.dirname(expectedPath);
+    if (!fs.existsSync(parent)) {
+      fs.mkdirSync(parent, {recursive: true});
+    }
+    fs.writeFileSync(expectedPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(expectedPath)) {
+      throw new Error(
+        `The file with the recorded trace does not exist: ${expectedPath}; ` +
+        `you probably want to set the environment ` +
+        `variable ${TestCommon.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected =
+      fs.readFileSync(expectedPath, "utf-8")
+      .replace(/\r\n/g, "\n");
+    expect(got).toStrictEqual(expected);
+  }
+}
+
+test("descendOnce of SomeItem", () => {
+  const instance = TestCommonJsonization.loadMaximalSomeItem();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descendOnce",
+      "SomeItem",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descendOnce of SpecialItem", () => {
+  const instance = TestCommonJsonization.loadMaximalSpecialItem();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descendOnce",
+      "SpecialItem",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descendOnce of Container", () => {
+  const instance = TestCommonJsonization.loadMaximalContainer();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descendOnce",
+      "Container",
+      "maximal.json.trace"
+    )
+  );
+});
+
+test("descendOnce of Wrapper", () => {
+  const instance = TestCommonJsonization.loadMaximalWrapper();
+
+  compareOrRecordTrace(
+    instance,
+    path.join(
+      TestCommon.TEST_DATA_DIR,
+      "descendOnce",
+      "Wrapper",
+      "maximal.json.trace"
+    )
+  );
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.modelType.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.modelType.spec.ts
new file mode 100644
index 000000000..bdf3f4c51
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.modelType.spec.ts
@@ -0,0 +1,148 @@
+/**
+ * Test `modelType()` methods.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "../src/types";
+import * as OurStringification from "../src/stringification";
+import * as TestCommonJsonization from "./commonJsonization";
+
+test("model type of SomeItem", () => {
+  const instance = TestCommonJsonization.loadMinimalSomeItem();
+
+  expect(instance.modelType()).toStrictEqual(
+    OurTypes.ModelType.SomeItem
+  );
+});
+
+test("model type from string of SomeItem", () => {
+  const text = "SomeItem";
+  const literal = OurStringification.modelTypeFromString(
+    text
+  );
+
+  expect(literal).toStrictEqual(
+    OurTypes.ModelType.SomeItem
+  );
+});
+
+test("model type to string of SomeItem", () => {
+  const text = OurStringification.mustModelTypeToString(
+    OurTypes.ModelType.SomeItem
+  );
+
+  expect(text).toStrictEqual(
+    "SomeItem"
+  );
+});
+
+test("model type of SpecialItem", () => {
+  const instance = TestCommonJsonization.loadMinimalSpecialItem();
+
+  expect(instance.modelType()).toStrictEqual(
+    OurTypes.ModelType.SpecialItem
+  );
+});
+
+test("model type from string of SpecialItem", () => {
+  const text = "SpecialItem";
+  const literal = OurStringification.modelTypeFromString(
+    text
+  );
+
+  expect(literal).toStrictEqual(
+    OurTypes.ModelType.SpecialItem
+  );
+});
+
+test("model type to string of SpecialItem", () => {
+  const text = OurStringification.mustModelTypeToString(
+    OurTypes.ModelType.SpecialItem
+  );
+
+  expect(text).toStrictEqual(
+    "SpecialItem"
+  );
+});
+
+test("model type of Container", () => {
+  const instance = TestCommonJsonization.loadMinimalContainer();
+
+  expect(instance.modelType()).toStrictEqual(
+    OurTypes.ModelType.Container
+  );
+});
+
+test("model type from string of Container", () => {
+  const text = "Container";
+  const literal = OurStringification.modelTypeFromString(
+    text
+  );
+
+  expect(literal).toStrictEqual(
+    OurTypes.ModelType.Container
+  );
+});
+
+test("model type to string of Container", () => {
+  const text = OurStringification.mustModelTypeToString(
+    OurTypes.ModelType.Container
+  );
+
+  expect(text).toStrictEqual(
+    "Container"
+  );
+});
+
+test("model type of Wrapper", () => {
+  const instance = TestCommonJsonization.loadMinimalWrapper();
+
+  expect(instance.modelType()).toStrictEqual(
+    OurTypes.ModelType.Wrapper
+  );
+});
+
+test("model type from string of Wrapper", () => {
+  const text = "Wrapper";
+  const literal = OurStringification.modelTypeFromString(
+    text
+  );
+
+  expect(literal).toStrictEqual(
+    OurTypes.ModelType.Wrapper
+  );
+});
+
+test("model type to string of Wrapper", () => {
+  const text = OurStringification.mustModelTypeToString(
+    OurTypes.ModelType.Wrapper
+  );
+
+  expect(text).toStrictEqual(
+    "Wrapper"
+  );
+});
+
+test("model type from invalid string", () => {
+  const text = "This is definitely not a valid model type.";
+  const literal = OurStringification.modelTypeFromString(
+    text
+  );
+
+  expect(literal).toBeNull();
+});
+
+test("invalid model type to string", () => {
+  // The number 9007199254740991 is the maximum safe integer.
+  const literal = <OurTypes.ModelType>9007199254740991;
+  const text = OurStringification.modelTypeToString(
+    literal
+  );
+
+  expect(text).toBeNull();
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overEnum.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overEnum.spec.ts
new file mode 100644
index 000000000..3727b3cdc
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overEnum.spec.ts
@@ -0,0 +1,11 @@
+/**
+ * Test `over{Enum}` functions.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "../src/types";
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overXOrEmpty.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overXOrEmpty.spec.ts
new file mode 100644
index 000000000..87bdaebab
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.overXOrEmpty.spec.ts
@@ -0,0 +1,37 @@
+/**
+ * Test `over*OrEmpty` methods.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as TestCommonJsonization from "./commonJsonization";
+
+test("Container.overSpecialItemsOrEmpty on maximal", () => {
+  const instance = TestCommonJsonization.loadMaximalContainer();
+
+  let count = 0;
+  for (const _ of instance.overSpecialItemsOrEmpty()) {
+    count++;
+  }
+
+  expect(count).toStrictEqual(
+    instance.specialItems?.length ?? 0,
+  );
+});
+
+test("Container.overSpecialItemsOrEmpty on minimal", () => {
+  const instance = TestCommonJsonization.loadMinimalContainer();
+
+  let count = 0;
+  for (const _ of instance.overSpecialItemsOrEmpty()) {
+    count++;
+  }
+
+  expect(count).toStrictEqual(
+    instance.specialItems?.length ?? 0,
+  );
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.typeMatches.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.typeMatches.spec.ts
new file mode 100644
index 000000000..15b725679
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.typeMatches.spec.ts
@@ -0,0 +1,140 @@
+/**
+ * Test `typesMatch`.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "../src/types";
+import * as TestCommonJsonization from "./commonJsonization";
+
+const THE_SOME_ITEM = TestCommonJsonization.loadMinimalSomeItem();
+
+const THE_SPECIAL_ITEM = TestCommonJsonization.loadMinimalSpecialItem();
+
+const THE_CONTAINER = TestCommonJsonization.loadMinimalContainer();
+
+const THE_WRAPPER = TestCommonJsonization.loadMinimalWrapper();
+
+test("type matches for SomeItem", () => {
+  expect(
+    OurTypes.typesMatch(
+      THE_SOME_ITEM,
+      THE_SOME_ITEM
+    )
+  ).toStrictEqual(true);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SOME_ITEM,
+      THE_SPECIAL_ITEM
+    )
+  ).toStrictEqual(true);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SOME_ITEM,
+      THE_CONTAINER
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SOME_ITEM,
+      THE_WRAPPER
+    )
+  ).toStrictEqual(false);
+});
+
+test("type matches for SpecialItem", () => {
+  expect(
+    OurTypes.typesMatch(
+      THE_SPECIAL_ITEM,
+      THE_SOME_ITEM
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SPECIAL_ITEM,
+      THE_SPECIAL_ITEM
+    )
+  ).toStrictEqual(true);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SPECIAL_ITEM,
+      THE_CONTAINER
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_SPECIAL_ITEM,
+      THE_WRAPPER
+    )
+  ).toStrictEqual(false);
+});
+
+test("type matches for Container", () => {
+  expect(
+    OurTypes.typesMatch(
+      THE_CONTAINER,
+      THE_SOME_ITEM
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_CONTAINER,
+      THE_SPECIAL_ITEM
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_CONTAINER,
+      THE_CONTAINER
+    )
+  ).toStrictEqual(true);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_CONTAINER,
+      THE_WRAPPER
+    )
+  ).toStrictEqual(false);
+});
+
+test("type matches for Wrapper", () => {
+  expect(
+    OurTypes.typesMatch(
+      THE_WRAPPER,
+      THE_SOME_ITEM
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_WRAPPER,
+      THE_SPECIAL_ITEM
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_WRAPPER,
+      THE_CONTAINER
+    )
+  ).toStrictEqual(false);
+
+  expect(
+    OurTypes.typesMatch(
+      THE_WRAPPER,
+      THE_WRAPPER
+    )
+  ).toStrictEqual(true);
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.xOrDefault.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.xOrDefault.spec.ts
new file mode 100644
index 000000000..3253e6f79
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/types.xOrDefault.spec.ts
@@ -0,0 +1,88 @@
+/**
+ * Test `*OrDefault` functions.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as path from "path";
+import * as fs from "fs";
+
+import * as OurStringification from "../src/stringification";
+import * as OurTypes from "../src/types";
+import * as TestCommon from "./common";
+import * as TestCommonJsonization from "./commonJsonization";
+
+/**
+ * Represent explicitly a literal of an enumeration.
+ */
+class EnumerationLiteral {
+  constructor(public enumerationName: string, public literalName) {
+    // Intentionally empty.
+  }
+
+  toString(): string {
+    return `${this.enumerationName}.${this.literalName}`;
+  }
+}
+
+/**
+ * Represent a value such that we can immediately check whether it is the default value
+ * or the set one.
+ *
+ * @remark
+ * We compare it against the recorded golden file, if not {@link common.RECORD_MODE}.
+ * Otherwise, when {@link common.RECORD_MODE} is set, we re-record the golden file.
+ *
+ * @param value - to be represented
+ * @param expectedPath - to the golden file
+ */
+function compareOrRecordValue(
+  value: boolean | number | string | null | EnumerationLiteral | OurTypes.Class,
+  expectedPath: string
+): void {
+  let got = "";
+  if (
+    typeof value === "boolean"
+    || typeof value === "number"
+    || typeof value === "string"
+    || value === null
+  ) {
+    got = JSON.stringify(value);
+  } else if (value instanceof EnumerationLiteral) {
+    got = value.toString();
+  } else if (value instanceof OurTypes.Class) {
+    got = TestCommon.traceMark(value);
+  } else {
+    throw new Error(`We do not know how to represent the value ${value}`);
+  }
+
+  // NOTE (mristin):
+  // We add a new line for POSIX systems which prefer a new line
+  // at the end of the file.
+  got += "\n";
+
+  if (TestCommon.RECORD_MODE) {
+    const parent = path.dirname(expectedPath);
+    if (!fs.existsSync(parent)) {
+      fs.mkdirSync(parent, {recursive: true});
+    }
+    fs.writeFileSync(expectedPath, got, "utf-8");
+  } else {
+    if (!fs.existsSync(expectedPath)) {
+      throw new Error(
+        `The file with the recorded value does not exist: ${expectedPath}; ` +
+        `you probably want to set the environment ` +
+        `variable ${TestCommon.RECORD_MODE_ENVIRONMENT_VARIABLE_NAME}?`
+      );
+    }
+
+    const expected =
+      fs.readFileSync(expectedPath, "utf-8")
+      .replace(/\r\n/g, "\n");
+    expect(got).toStrictEqual(expected);
+  }
+}
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/verification.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/verification.spec.ts
new file mode 100644
index 000000000..5ee1ece36
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/verification.spec.ts
@@ -0,0 +1,49 @@
+/**
+ * Test verification helper classes and string-based verification functions.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurTypes from "../src/types";
+import * as OurVerification from "../src/verification";
+
+test("verification path and segments format", () => {
+  const path = new OurVerification.Path();
+
+  path.prepend(
+    new OurVerification.IndexSegment(
+      <Array<OurTypes.Class>>[],
+      2
+    )
+  );
+  path.prepend(
+    new OurVerification.PropertySegment(
+      <OurTypes.Class>{},
+      "something"
+    )
+  );
+
+  expect(path.toString()).toStrictEqual(".something[2]");
+});
+
+test("verification error stores provided path", () => {
+  const path = new OurVerification.Path();
+  path.prepend(
+    new OurVerification.PropertySegment(
+      <OurTypes.Class>{},
+      "idShort"
+    )
+  );
+
+  const error = new OurVerification.VerificationError(
+    "Some verification error",
+    path
+  );
+
+  expect(error.message).toStrictEqual("Some verification error");
+  expect(error.path.toString()).toStrictEqual(".idShort");
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.basic.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.basic.spec.ts
new file mode 100644
index 000000000..18592ec9d
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.basic.spec.ts
@@ -0,0 +1,68 @@
+/**
+ * Test basic XMLization helper classes and malformed XML inputs.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurXmlization from "../src/xmlization";
+
+test("xmlization path renders as a relative XPath", () => {
+  const path = new OurXmlization.Path();
+
+  path.prepend(new OurXmlization.IndexSegment(3));
+  path.prepend(new OurXmlization.ElementSegment("something"));
+
+  expect(path.toString()).toStrictEqual("something/*[4]");
+});
+
+test("xmlization key segment renders as a predicate on the name", () => {
+  const path = new OurXmlization.Path();
+
+  path.prepend(new OurXmlization.ElementSegment("value"));
+  path.prepend(new OurXmlization.KeySegment("a \"tricky\" <key>"));
+  path.prepend(new OurXmlization.ElementSegment("struct"));
+
+  expect(path.toString()).toStrictEqual(
+    "struct/member[name=\"a &quot;tricky&quot; &lt;key&gt;\"]/value"
+  );
+});
+
+test("xmlization errors default to empty path", () => {
+  const deserializationError = new OurXmlization.DeserializationError("broken XML");
+  expect(deserializationError.message).toStrictEqual("broken XML");
+  expect(deserializationError.path.toString()).toStrictEqual("");
+
+  const serializationError = new OurXmlization.SerializationError("broken object graph");
+  expect(serializationError.message).toStrictEqual("broken object graph");
+  expect(serializationError.path).toStrictEqual("");
+});
+
+test("xmlization serialization path renders as an access expression", () => {
+  const error = new OurXmlization.SerializationError("broken object graph");
+
+  error.prependKey("a b");
+  error.prependIndex(3);
+  error.prependProperty("something");
+
+  expect(error.path).toStrictEqual('.something[3]["a b"]');
+});
+
+test("xmlization fails on malformed XML", () => {
+  const malformedXml = "<something><notClosed>";
+  const instanceOrError = OurXmlization.fromXmlString(malformedXml);
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test("xmlization fails on empty XML", () => {
+  const instanceOrError = OurXmlization.fromXmlString("");
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test("xmlization fails on non-XML text", () => {
+  const instanceOrError = OurXmlization.fromXmlString("Definitely not XML");
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.common.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.common.spec.ts
new file mode 100644
index 000000000..25dc04250
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.common.spec.ts
@@ -0,0 +1,31 @@
+/**
+ * Execute all common XMLization loader helpers once.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as TestCommonXmlization from "./commonXmlization";
+
+test("commonXmlization loaders for SomeItem", () => {
+  expect(TestCommonXmlization.loadMinimalSomeItem()).not.toBeNull();
+  expect(TestCommonXmlization.loadMaximalSomeItem()).not.toBeNull();
+});
+
+test("commonXmlization loaders for SpecialItem", () => {
+  expect(TestCommonXmlization.loadMinimalSpecialItem()).not.toBeNull();
+  expect(TestCommonXmlization.loadMaximalSpecialItem()).not.toBeNull();
+});
+
+test("commonXmlization loaders for Container", () => {
+  expect(TestCommonXmlization.loadMinimalContainer()).not.toBeNull();
+  expect(TestCommonXmlization.loadMaximalContainer()).not.toBeNull();
+});
+
+test("commonXmlization loaders for Wrapper", () => {
+  expect(TestCommonXmlization.loadMinimalWrapper()).not.toBeNull();
+  expect(TestCommonXmlization.loadMaximalWrapper()).not.toBeNull();
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.concreteClasses.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.concreteClasses.spec.ts
new file mode 100644
index 000000000..5435fad54
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.concreteClasses.spec.ts
@@ -0,0 +1,306 @@
+/**
+ * Test XML de/serialization of concrete classes.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as fs from "fs";
+import * as path from "path";
+
+import * as OurXmlization from "../src/xmlization";
+import * as OurTypes from "../src/types";
+import * as OurVerification from "../src/verification";
+
+import * as TestCommon from "./common";
+
+test("SomeItem XML round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Expected",
+        "someItem"
+      ),
+      ".xml"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const text = fs.readFileSync(pth, "utf-8");
+
+    const instanceOrError = OurXmlization.fromXmlString(text);
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    const casted = OurTypes.asSomeItem(instance);
+    if (casted === null) {
+      throw new Error(
+        `Expected instance of SomeItem in ${pth}, ` +
+        `but got: ${typeof instance}`
+      );
+    }
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(casted), pth);
+
+    const roundTripText = OurXmlization.toXmlString(casted);
+    expect(roundTripText.length).toBeGreaterThan(0);
+  }
+});
+
+test("SomeItem XML deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "someItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".xml"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const text = fs.readFileSync(pth, "utf-8");
+      const instanceOrError = OurXmlization.fromXmlString(text);
+      expect(instanceOrError.error).not.toBeNull();
+    }
+  }
+});
+
+test("SpecialItem XML round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Expected",
+        "specialItem"
+      ),
+      ".xml"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const text = fs.readFileSync(pth, "utf-8");
+
+    const instanceOrError = OurXmlization.fromXmlString(text);
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    const casted = OurTypes.asSpecialItem(instance);
+    if (casted === null) {
+      throw new Error(
+        `Expected instance of SpecialItem in ${pth}, ` +
+        `but got: ${typeof instance}`
+      );
+    }
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(casted), pth);
+
+    const roundTripText = OurXmlization.toXmlString(casted);
+    expect(roundTripText.length).toBeGreaterThan(0);
+  }
+});
+
+test("SpecialItem XML deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "specialItem"
+    );
+    if (!fs.existsSync(clsDir)) {
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".xml"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const text = fs.readFileSync(pth, "utf-8");
+      const instanceOrError = OurXmlization.fromXmlString(text);
+      expect(instanceOrError.error).not.toBeNull();
+    }
+  }
+});
+
+test("Container XML round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Expected",
+        "container"
+      ),
+      ".xml"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const text = fs.readFileSync(pth, "utf-8");
+
+    const instanceOrError = OurXmlization.fromXmlString(text);
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    const casted = OurTypes.asContainer(instance);
+    if (casted === null) {
+      throw new Error(
+        `Expected instance of Container in ${pth}, ` +
+        `but got: ${typeof instance}`
+      );
+    }
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(casted), pth);
+
+    const roundTripText = OurXmlization.toXmlString(casted);
+    expect(roundTripText.length).toBeGreaterThan(0);
+  }
+});
+
+test("Container XML deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "container"
+    );
+    if (!fs.existsSync(clsDir)) {
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".xml"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const text = fs.readFileSync(pth, "utf-8");
+      const instanceOrError = OurXmlization.fromXmlString(text);
+      expect(instanceOrError.error).not.toBeNull();
+    }
+  }
+});
+
+test("Wrapper XML round-trip OK", () => {
+  const pths = Array.from(
+    TestCommon.findFilesBySuffixRecursively(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Expected",
+        "wrapper"
+      ),
+      ".xml"
+    )
+  );
+  pths.sort();
+
+  for (const pth of pths) {
+    const text = fs.readFileSync(pth, "utf-8");
+
+    const instanceOrError = OurXmlization.fromXmlString(text);
+    expect(instanceOrError.error).toBeNull();
+    const instance = instanceOrError.mustValue();
+
+    const casted = OurTypes.asWrapper(instance);
+    if (casted === null) {
+      throw new Error(
+        `Expected instance of Wrapper in ${pth}, ` +
+        `but got: ${typeof instance}`
+      );
+    }
+
+    TestCommon.assertNoVerificationErrors(OurVerification.verify(casted), pth);
+
+    const roundTripText = OurXmlization.toXmlString(casted);
+    expect(roundTripText.length).toBeGreaterThan(0);
+  }
+});
+
+test("Wrapper XML deserialization fail", () => {
+  for (
+    const causeDir of
+    TestCommon.findImmediateSubdirectories(
+      path.join(
+        TestCommon.TEST_DATA_DIR,
+        "Xml",
+        "Unexpected",
+        "Unserializable"
+      )
+    )
+  ) {
+    const clsDir = path.join(
+      causeDir,
+      "wrapper"
+    );
+    if (!fs.existsSync(clsDir)) {
+      continue;
+    }
+
+    const pths = Array.from(
+      TestCommon.findFilesBySuffixRecursively(
+        clsDir,
+        ".xml"
+      )
+    );
+    pths.sort();
+
+    for (const pth of pths) {
+      const text = fs.readFileSync(pth, "utf-8");
+      const instanceOrError = OurXmlization.fromXmlString(text);
+      expect(instanceOrError.error).not.toBeNull();
+    }
+  }
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.enums.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.enums.spec.ts
new file mode 100644
index 000000000..db7bcb130
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.enums.spec.ts
@@ -0,0 +1,14 @@
+/**
+ * Test XML de/serialization of enumeration literals.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurXmlization from "../src/xmlization";
+import * as OurTypes from "../src/types";
+
+import * as TestCommonXmlization from "./commonXmlization";
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.interfaces.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.interfaces.spec.ts
new file mode 100644
index 000000000..8eadbda48
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.interfaces.spec.ts
@@ -0,0 +1,166 @@
+/**
+ * Test XML de/serialization of interfaces.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as OurXmlization from "../src/xmlization";
+import * as OurTypes from "../src/types";
+
+import * as TestCommonXmlization from "./commonXmlization";
+
+test(
+  "IItem XML round-trip " +
+  "starting from SomeItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSomeItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.fromXmlString(xmlText);
+    expect(anotherInstanceOrError.error).toBeNull();
+    const anotherInstance = anotherInstanceOrError.mustValue();
+
+    const asInterface = OurTypes.asItem(anotherInstance);
+    expect(asInterface).not.toBeNull();
+  }
+);
+
+test(
+  "IItem XML round-trip via " +
+  "itemFromXmlString starting from SomeItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSomeItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.itemFromXmlString(
+      xmlText
+    );
+    expect(anotherInstanceOrError.error).toBeNull();
+  }
+);
+
+test(
+  "IItem XML round-trip " +
+  "starting from SpecialItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSpecialItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.fromXmlString(xmlText);
+    expect(anotherInstanceOrError.error).toBeNull();
+    const anotherInstance = anotherInstanceOrError.mustValue();
+
+    const asInterface = OurTypes.asItem(anotherInstance);
+    expect(asInterface).not.toBeNull();
+  }
+);
+
+test(
+  "IItem XML round-trip via " +
+  "itemFromXmlString starting from SpecialItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSpecialItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.itemFromXmlString(
+      xmlText
+    );
+    expect(anotherInstanceOrError.error).toBeNull();
+  }
+);
+
+test("IItem XML deserialization fail", () => {
+  const instanceOrError = OurXmlization.fromXmlString("This is not XML.");
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test(
+  "IItem XML deserialization fail via " +
+  "itemFromXmlString",
+  () => {
+    const instanceOrError = OurXmlization.itemFromXmlString(
+      "This is not XML."
+    );
+    expect(instanceOrError.error).not.toBeNull();
+  }
+);
+
+test(
+  "ISomeItem XML round-trip " +
+  "starting from SpecialItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSpecialItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.fromXmlString(xmlText);
+    expect(anotherInstanceOrError.error).toBeNull();
+    const anotherInstance = anotherInstanceOrError.mustValue();
+
+    const asInterface = OurTypes.asSomeItem(anotherInstance);
+    expect(asInterface).not.toBeNull();
+  }
+);
+
+test(
+  "ISomeItem XML round-trip via " +
+  "someItemFromXmlString starting from SpecialItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSpecialItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.someItemFromXmlString(
+      xmlText
+    );
+    expect(anotherInstanceOrError.error).toBeNull();
+  }
+);
+
+test(
+  "ISomeItem XML round-trip " +
+  "starting from SomeItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSomeItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.fromXmlString(xmlText);
+    expect(anotherInstanceOrError.error).toBeNull();
+    const anotherInstance = anotherInstanceOrError.mustValue();
+
+    const asInterface = OurTypes.asSomeItem(anotherInstance);
+    expect(asInterface).not.toBeNull();
+  }
+);
+
+test(
+  "ISomeItem XML round-trip via " +
+  "someItemFromXmlString starting from SomeItem OK",
+  () => {
+    const instance = TestCommonXmlization.loadMinimalSomeItem();
+
+    const xmlText = OurXmlization.toXmlString(instance);
+    const anotherInstanceOrError = OurXmlization.someItemFromXmlString(
+      xmlText
+    );
+    expect(anotherInstanceOrError.error).toBeNull();
+  }
+);
+
+test("ISomeItem XML deserialization fail", () => {
+  const instanceOrError = OurXmlization.fromXmlString("This is not XML.");
+  expect(instanceOrError.error).not.toBeNull();
+});
+
+test(
+  "ISomeItem XML deserialization fail via " +
+  "someItemFromXmlString",
+  () => {
+    const instanceOrError = OurXmlization.someItemFromXmlString(
+      "This is not XML."
+    );
+    expect(instanceOrError.error).not.toBeNull();
+  }
+);
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.negative.spec.ts b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.negative.spec.ts
new file mode 100644
index 000000000..eb108073a
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/expected_output/test/xmlization.negative.spec.ts
@@ -0,0 +1,133 @@
+/**
+ * Test failure modes in XML parsing to exercise defensive branches.
+ */
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
+
+import * as fs from "fs";
+import * as path from "path";
+
+// NOTE (mristin):
+// Initially, we used string operations to manipulate the XML files, but that lead
+// to maintainability problems. For example, we suddenly had to take care of edge
+// cases such as self-closing elements (e.g., `<something />`). Instead, we decided
+// to use a proper library. There is a DOMParser in XMLSerializer provided in
+// the browser, but node.js does not ship with them, unless we explicitly add "dom".
+//
+// In the end, we decided to use an external library as development dependency since
+// all the other approaches (gymnastics with jest, tsconfig and tsconfig.test) turned
+// out to be much more complicated.
+import { DOMParser, XMLSerializer } from "@xmldom/xmldom";
+import type { Document } from "@xmldom/xmldom";
+
+import * as OurXmlization from "../src/xmlization";
+
+import * as TestCommon from "./common";
+
+function parseXml(xmlText: string): [Document, null] | [null, string] {
+  let errorMessage: string | null = null;
+
+  const document = new DOMParser({
+    errorHandler: (level: string, msg: string) => {
+      if (level === "error" || level === "fatalError") {
+        errorMessage = msg;
+      }
+    }
+  }).parseFromString(xmlText, "application/xml");
+
+  return errorMessage !== null ? [null, errorMessage] : [document, null];
+}
+
+function expectDeserializationError(xmlText: string): void {
+  const instanceOrError = OurXmlization.fromXmlString(xmlText);
+  expect(instanceOrError.error).not.toBeNull();
+}
+
+test("XML namespace mismatch fails", () => {
+  const pth = path.join(
+    TestCommon.TEST_DATA_DIR, "Xml", "Expected", "someItem", "minimal.xml"
+  );
+  const text = fs.readFileSync(pth, "utf-8");
+  const brokenText = text.replace(
+    /xmlns="[^"]*"/,
+    'xmlns="urn:aas-core-codegen:broken"'
+  );
+
+  expect(brokenText).not.toStrictEqual(text);
+  expectDeserializationError(brokenText);
+});
+
+test("XML wrong root closing element fails", () => {
+  const pth = path.join(
+    TestCommon.TEST_DATA_DIR, "Xml", "Expected", "someItem", "minimal.xml"
+  );
+  const text = fs.readFileSync(pth, "utf-8");
+
+  // NOTE (mristin):
+  // The root element might be self-closing (*e.g.*, `<someItem .../>`)
+  // if it has no content, in which case there is no separate closing tag to
+  // corrupt. We handle the two cases distinctly.
+  const selfClosingRegex = new RegExp("<someItem(?=[^>]*/>)");
+  const selfClosingMatch = text.match(selfClosingRegex);
+
+  let brokenText: string;
+  if (selfClosingMatch !== null && selfClosingMatch.index !== undefined) {
+    brokenText =
+      text.slice(0, selfClosingMatch.index) +
+      "<someItem_BROKEN" +
+      text.slice(selfClosingMatch.index + selfClosingMatch[0].length);
+  } else {
+    const expectedClosing = "</someItem>";
+    const insertionIndex = text.lastIndexOf(expectedClosing);
+    if (insertionIndex < 0) {
+      throw new Error(`Failed to find root closing tag: ${expectedClosing}`);
+    }
+
+    const brokenClosing = "</someItem_BROKEN>";
+    brokenText =
+      text.slice(0, insertionIndex) +
+      brokenClosing +
+      text.slice(insertionIndex + expectedClosing.length);
+  }
+
+  expect(brokenText).not.toStrictEqual(text);
+  expectDeserializationError(brokenText);
+});
+
+test("XML duplicate property fails", () => {
+  const propertyName = "name";
+
+  const pth = path.join(
+    TestCommon.TEST_DATA_DIR, "Xml", "Expected", "someItem", "minimal.xml"
+  );
+  const [document, parseError] = parseXml(fs.readFileSync(pth, "utf-8"));
+  if (parseError !== null) {
+    throw new Error(`Invalid XML fixture: ${parseError}`);
+  }
+
+  const root = document.documentElement;
+  if (root.tagName !== "someItem") {
+    throw new Error(
+      `Expected root element <someItem>, ` +
+      `got <${root.tagName}>`
+    );
+  }
+
+  const property = Array.from(root.children).find(
+    (child) => child.tagName === propertyName
+  );
+
+  if (property === undefined) {
+    throw new Error(`Failed to find property element: ${propertyName}`);
+  }
+
+  root.appendChild(property.cloneNode(true));
+
+  const brokenText = new XMLSerializer().serializeToString(document);
+
+  expectDeserializationError(brokenText);
+});
+
+// This code has been automatically generated by aas-core-codegen.
+// Do NOT edit or append.
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_documentation.txt b/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_documentation.txt
new file mode 100644
index 000000000..9f755e913
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_documentation.txt
@@ -0,0 +1 @@
+Provide dummy SDK.
\ No newline at end of file
diff --git a/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_identifier.txt b/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_identifier.txt
new file mode 100644
index 000000000..edcbd8ba9
--- /dev/null
+++ b/dev/test_data/main/typescript/expected/variance_of_containers/input/snippets/package_identifier.txt
@@ -0,0 +1 @@
+@dummy-works/dummy
diff --git a/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/schema.xsd b/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/schema.xsd
new file mode 100644
index 000000000..b25f41e08
--- /dev/null
+++ b/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/schema.xsd
@@ -0,0 +1,88 @@
+<?xml version="1.0" ?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="https://dummy.com" elementFormDefault="qualified" targetNamespace="https://dummy.com">
+  <xs:group name="container">
+    <xs:sequence>
+      <xs:element name="items">
+        <xs:complexType>
+          <xs:sequence>
+            <xs:group ref="item_choice" minOccurs="0" maxOccurs="unbounded"/>
+          </xs:sequence>
+        </xs:complexType>
+      </xs:element>
+      <xs:element name="someItems">
+        <xs:complexType>
+          <xs:sequence>
+            <xs:group ref="someItem_choice" minOccurs="0" maxOccurs="unbounded"/>
+          </xs:sequence>
+        </xs:complexType>
+      </xs:element>
+      <xs:element name="specialItems" minOccurs="0" maxOccurs="1">
+        <xs:complexType>
+          <xs:sequence>
+            <xs:element name="specialItem" type="specialItem_t" minOccurs="0" maxOccurs="unbounded"/>
+          </xs:sequence>
+        </xs:complexType>
+      </xs:element>
+    </xs:sequence>
+  </xs:group>
+  <xs:group name="item">
+    <xs:sequence>
+      <xs:element name="name" type="xs:string"/>
+      <xs:element name="nickname" type="xs:string" minOccurs="0" maxOccurs="1"/>
+    </xs:sequence>
+  </xs:group>
+  <xs:group name="item_choice">
+    <xs:choice>
+      <xs:element name="someItem" type="someItem_t"/>
+      <xs:element name="specialItem" type="specialItem_t"/>
+    </xs:choice>
+  </xs:group>
+  <xs:group name="someItem">
+    <xs:sequence>
+      <xs:group ref="item"/>
+    </xs:sequence>
+  </xs:group>
+  <xs:group name="someItem_choice">
+    <xs:choice>
+      <xs:element name="someItem" type="someItem_t"/>
+      <xs:element name="specialItem" type="specialItem_t"/>
+    </xs:choice>
+  </xs:group>
+  <xs:group name="specialItem">
+    <xs:sequence>
+      <xs:group ref="someItem"/>
+      <xs:element name="level" type="xs:long"/>
+    </xs:sequence>
+  </xs:group>
+  <xs:group name="wrapper">
+    <xs:sequence>
+      <xs:element name="container" type="container_t"/>
+    </xs:sequence>
+  </xs:group>
+  <xs:complexType name="container_t">
+    <xs:sequence>
+      <xs:group ref="container"/>
+    </xs:sequence>
+  </xs:complexType>
+  <xs:complexType name="item_t">
+    <xs:sequence>
+      <xs:group ref="item"/>
+    </xs:sequence>
+  </xs:complexType>
+  <xs:complexType name="someItem_t">
+    <xs:sequence>
+      <xs:group ref="someItem"/>
+    </xs:sequence>
+  </xs:complexType>
+  <xs:complexType name="specialItem_t">
+    <xs:sequence>
+      <xs:group ref="specialItem"/>
+    </xs:sequence>
+  </xs:complexType>
+  <xs:complexType name="wrapper_t">
+    <xs:sequence>
+      <xs:group ref="wrapper"/>
+    </xs:sequence>
+  </xs:complexType>
+  <xs:element name="container" type="container_t"/>
+</xs:schema>
diff --git a/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/stdout.txt b/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/stdout.txt
new file mode 100644
index 000000000..2d755fc5a
--- /dev/null
+++ b/dev/test_data/main/xsd/expected/variance_of_containers/expected_output/stdout.txt
@@ -0,0 +1 @@
+Code generated to: <output dir>
diff --git a/dev/test_data/main/xsd/expected/variance_of_containers/input/snippets/root_element.xml b/dev/test_data/main/xsd/expected/variance_of_containers/input/snippets/root_element.xml
new file mode 100644
index 000000000..392e7c032
--- /dev/null
+++ b/dev/test_data/main/xsd/expected/variance_of_containers/input/snippets/root_element.xml
@@ -0,0 +1,8 @@
+<xs:schema
+        xmlns:xs="http://www.w3.org/2001/XMLSchema"
+        xmlns="https://dummy.com"
+        elementFormDefault="qualified"
+        targetNamespace="https://dummy.com"
+>
+    <xs:element name="container" type="container_t" />
+</xs:schema>
diff --git a/dev/test_data/parse/common_meta_models/variance_of_containers/expected_symbol_table.txt b/dev/test_data/parse/common_meta_models/variance_of_containers/expected_symbol_table.txt
new file mode 100644
index 000000000..c400ec748
--- /dev/null
+++ b/dev/test_data/parse/common_meta_models/variance_of_containers/expected_symbol_table.txt
@@ -0,0 +1,2252 @@
+UnverifiedSymbolTable(
+  our_types=[
+    AbstractClass(
+      name='Item',
+      inheritances=[],
+      properties=[
+        Property(
+          name='name',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='str',
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...),
+        Property(
+          name='nickname',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Optional',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='str',
+                node=...)],
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...)],
+      methods=[
+        ConstructorToBeUnderstood(
+          name='__init__',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='name',
+              type_annotation=AtomicTypeAnnotation(
+                identifier='str',
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='nickname',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='Optional',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='str',
+                    node=...)],
+                node=...),
+              default=Default(
+                node=...),
+              node=...)],
+          returns=None,
+          description=None,
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=False,
+          node=...,
+          arguments_by_name=...,
+          body=...)],
+      invariants=[],
+      serialization=Serialization(
+        with_model_type=True),
+      description=None,
+      node=...,
+      properties_by_name=...,
+      methods_by_name=...),
+    ConcreteClass(
+      name='Some_item',
+      inheritances=[
+        'Item'],
+      properties=[],
+      methods=[
+        ConstructorToBeUnderstood(
+          name='__init__',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='name',
+              type_annotation=AtomicTypeAnnotation(
+                identifier='str',
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='nickname',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='Optional',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='str',
+                    node=...)],
+                node=...),
+              default=Default(
+                node=...),
+              node=...)],
+          returns=None,
+          description=None,
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=False,
+          node=...,
+          arguments_by_name=...,
+          body=...)],
+      invariants=[],
+      serialization=None,
+      description=None,
+      node=...,
+      properties_by_name=...,
+      methods_by_name=...),
+    ConcreteClass(
+      name='Special_item',
+      inheritances=[
+        'Some_item'],
+      properties=[
+        Property(
+          name='level',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='int',
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...)],
+      methods=[
+        ConstructorToBeUnderstood(
+          name='__init__',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='name',
+              type_annotation=AtomicTypeAnnotation(
+                identifier='str',
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='level',
+              type_annotation=AtomicTypeAnnotation(
+                identifier='int',
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='nickname',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='Optional',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='str',
+                    node=...)],
+                node=...),
+              default=Default(
+                node=...),
+              node=...)],
+          returns=None,
+          description=None,
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=False,
+          node=...,
+          arguments_by_name=...,
+          body=...)],
+      invariants=[],
+      serialization=None,
+      description=None,
+      node=...,
+      properties_by_name=...,
+      methods_by_name=...),
+    ConcreteClass(
+      name='Container',
+      inheritances=[],
+      properties=[
+        Property(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='List',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...),
+        Property(
+          name='some_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='List',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Some_item',
+                node=...)],
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...),
+        Property(
+          name='special_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Optional',
+            subscripts=[
+              SubscriptedTypeAnnotation(
+                identifier='List',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Special_item',
+                    node=...)],
+                node=...)],
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...)],
+      methods=[
+        UnderstoodMethod(
+          name='count_items',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='items',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='Sequence',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Item',
+                    node=...)],
+                node=...),
+              default=None,
+              node=...)],
+          returns=AtomicTypeAnnotation(
+            identifier='int',
+            node=...),
+          description=Description(
+            document=...,
+            node=...),
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=True,
+          body=[
+            textwrap.dedent("""\
+              Return(
+                value=FunctionCall(
+                  name='len',
+                  args=[
+                    Name(
+                      identifier='items',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...)""")],
+          node=...,
+          arguments_by_name=...),
+        ConstructorToBeUnderstood(
+          name='__init__',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='items',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='List',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Item',
+                    node=...)],
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='some_items',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='List',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Some_item',
+                    node=...)],
+                node=...),
+              default=None,
+              node=...),
+            Argument(
+              name='special_items',
+              type_annotation=SubscriptedTypeAnnotation(
+                identifier='Optional',
+                subscripts=[
+                  SubscriptedTypeAnnotation(
+                    identifier='List',
+                    subscripts=[
+                      AtomicTypeAnnotation(
+                        identifier='Special_item',
+                        node=...)],
+                    node=...)],
+                node=...),
+              default=Default(
+                node=...),
+              node=...)],
+          returns=None,
+          description=None,
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=False,
+          node=...,
+          arguments_by_name=...,
+          body=...)],
+      invariants=[
+        Invariant(
+          description='Each special item must be among the special items.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=All(
+                generator=ForEach(
+                  variable=Name(
+                    identifier='special_item',
+                    original_node=...),
+                  iteration=Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...),
+                  original_node=...),
+                condition=FunctionCall(
+                  name='contains_special_item',
+                  args=[
+                    Name(
+                      identifier='special_item',
+                      original_node=...),
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='special_items',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='If there are some items, they must overlap with the items.',
+          body=textwrap.dedent("""\
+            Or(
+              values=[
+                Comparison(
+                  left=FunctionCall(
+                    name='len',
+                    args=[
+                      Member(
+                        instance=Name(
+                          identifier='self',
+                          original_node=...),
+                        name='some_items',
+                        original_node=...)],
+                    original_node=...),
+                  op='EQ',
+                  right=Constant(
+                    value=0,
+                    original_node=...),
+                  original_node=...),
+                FunctionCall(
+                  name='items_overlap',
+                  args=[
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='items',
+                      original_node=...),
+                    Member(
+                      instance=Name(
+                        identifier='self',
+                        original_node=...),
+                      name='some_items',
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Some items must be among the items.',
+          body=textwrap.dedent("""\
+            All(
+              generator=ForEach(
+                variable=Name(
+                  identifier='some_item',
+                  original_node=...),
+                iteration=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                original_node=...),
+              condition=FunctionCall(
+                name='contains_some_item',
+                args=[
+                  Name(
+                    identifier='some_item',
+                    original_node=...),
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of some items and of special items must be unique through aliases.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='aliased_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of the items and of some items must be disjoint.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_disjoint',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Constant(
+                  value='x',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='If there is a special item with level, the last item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=FunctionCall(
+                name='some_special_item_has_level',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              consequent=FunctionCall(
+                name='last_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Levels of the special items among the items must be positive.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='levels_of_special_items_are_positive',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Nicknames of some items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='nicknames_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Count of the items must match the number of the items.',
+          body=textwrap.dedent("""\
+            Comparison(
+              left=MethodCall(
+                member=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='count_items',
+                  original_node=...),
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              op='EQ',
+              right=FunctionCall(
+                name='len',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of the special items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='optional_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='The first special item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=FunctionCall(
+                name='first_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Levels of the special items must be positive.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=IsNotNone(
+                value=Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...),
+                original_node=...),
+              consequent=FunctionCall(
+                name='levels_are_positive',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='special_items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='If there is a special item with level, the first item must be special.',
+          body=textwrap.dedent("""\
+            Implication(
+              antecedent=FunctionCall(
+                name='some_special_item_has_level',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              consequent=FunctionCall(
+                name='first_is_special',
+                args=[
+                  Member(
+                    instance=Name(
+                      identifier='self',
+                      original_node=...),
+                    name='items',
+                    original_node=...)],
+                original_node=...),
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of some items must be non-empty.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_non_empty',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of some items and of special items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='some_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='some_items',
+                  original_node=...),
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='special_items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...),
+        Invariant(
+          description='Names of the items must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='items',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...)],
+      serialization=None,
+      description=None,
+      node=...,
+      properties_by_name=...,
+      methods_by_name=...),
+    ConcreteClass(
+      name='Wrapper',
+      inheritances=[],
+      properties=[
+        Property(
+          name='container',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='Container',
+            node=...),
+          description=None,
+          json_name=None,
+          xml_name=None,
+          node=...)],
+      methods=[
+        ConstructorToBeUnderstood(
+          name='__init__',
+          verification=False,
+          visibility='PUBLIC',
+          arguments=[
+            Argument(
+              name='self',
+              type_annotation=SelfTypeAnnotation(),
+              default=None,
+              node=...),
+            Argument(
+              name='container',
+              type_annotation=AtomicTypeAnnotation(
+                identifier='Container',
+                node=...),
+              default=None,
+              node=...)],
+          returns=None,
+          description=None,
+          contracts=Contracts(
+            preconditions=[],
+            snapshots=[],
+            postconditions=[]),
+          non_mutating=False,
+          node=...,
+          arguments_by_name=...,
+          body=...)],
+      invariants=[
+        Invariant(
+          description='Names of some items of the container must be unique.',
+          body=textwrap.dedent("""\
+            FunctionCall(
+              name='container_names_are_unique',
+              args=[
+                Member(
+                  instance=Name(
+                    identifier='self',
+                    original_node=...),
+                  name='container',
+                  original_node=...)],
+              original_node=...)"""),
+          node=...)],
+      serialization=None,
+      description=None,
+      node=...,
+      properties_by_name=...,
+      methods_by_name=...)],
+  named_unions=[],
+  constants=[],
+  verification_functions=[
+    UnderstoodMethod(
+      name='names_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='name_set',
+              original_node=...),
+            value=FunctionCall(
+              name='set',
+              args=[],
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Set',
+                original_node=...),
+              index=Name(
+                identifier='str',
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          For(
+            generator=ForEach(
+              variable=Name(
+                identifier='item',
+                original_node=...),
+              iteration=Name(
+                identifier='items',
+                original_node=...),
+              original_node=...),
+            body=[
+              If(
+                branches=[
+                  IfBranch(
+                    condition=IsIn(
+                      member=Member(
+                        instance=Name(
+                          identifier='item',
+                          original_node=...),
+                        name='name',
+                        original_node=...),
+                      container=Name(
+                        identifier='name_set',
+                        original_node=...),
+                      original_node=...),
+                    body=[
+                      Return(
+                        value=Constant(
+                          value=False,
+                          original_node=...),
+                        original_node=...)],
+                    original_node=...)],
+                default=None,
+                original_node=...),
+              ExpressionStatement(
+                expression=MethodCall(
+                  member=Member(
+                    instance=Name(
+                      identifier='name_set',
+                      original_node=...),
+                    name='add',
+                    original_node=...),
+                  args=[
+                    Member(
+                      instance=Name(
+                        identifier='item',
+                        original_node=...),
+                      name='name',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...)],
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=Constant(
+              value=True,
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='names_are_non_empty',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=All(
+              generator=ForEach(
+                variable=Name(
+                  identifier='item',
+                  original_node=...),
+                iteration=Name(
+                  identifier='items',
+                  original_node=...),
+                original_node=...),
+              condition=Comparison(
+                left=FunctionCall(
+                  name='len',
+                  args=[
+                    Member(
+                      instance=Name(
+                        identifier='item',
+                        original_node=...),
+                      name='name',
+                      original_node=...)],
+                  original_node=...),
+                op='GT',
+                right=Constant(
+                  value=0,
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='some_special_item_has_level',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=Any(
+              generator=ForEach(
+                variable=Name(
+                  identifier='item',
+                  original_node=...),
+                iteration=Name(
+                  identifier='items',
+                  original_node=...),
+                original_node=...),
+              condition=And(
+                values=[
+                  IsInstance(
+                    value=Name(
+                      identifier='item',
+                      original_node=...),
+                    classes=[
+                      Name(
+                        identifier='Special_item',
+                        original_node=...)],
+                    original_node=...),
+                  Comparison(
+                    left=Member(
+                      instance=Name(
+                        identifier='item',
+                        original_node=...),
+                      name='level',
+                      original_node=...),
+                    op='GT',
+                    right=Constant(
+                      value=0,
+                      original_node=...),
+                    original_node=...)],
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='first_is_special',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          If(
+            branches=[
+              IfBranch(
+                condition=Comparison(
+                  left=FunctionCall(
+                    name='len',
+                    args=[
+                      Name(
+                        identifier='items',
+                        original_node=...)],
+                    original_node=...),
+                  op='EQ',
+                  right=Constant(
+                    value=0,
+                    original_node=...),
+                  original_node=...),
+                body=[
+                  Return(
+                    value=Constant(
+                      value=False,
+                      original_node=...),
+                    original_node=...)],
+                original_node=...)],
+            default=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='first',
+              original_node=...),
+            value=Index(
+              collection=Name(
+                identifier='items',
+                original_node=...),
+              index=Constant(
+                value=0,
+                original_node=...),
+              original_node=...),
+            annotation=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          If(
+            branches=[
+              IfBranch(
+                condition=IsInstance(
+                  value=Name(
+                    identifier='first',
+                    original_node=...),
+                  classes=[
+                    Name(
+                      identifier='Special_item',
+                      original_node=...)],
+                  original_node=...),
+                body=[
+                  Return(
+                    value=Comparison(
+                      left=Member(
+                        instance=Name(
+                          identifier='first',
+                          original_node=...),
+                        name='level',
+                        original_node=...),
+                      op='GT',
+                      right=Constant(
+                        value=0,
+                        original_node=...),
+                      original_node=...),
+                    original_node=...)],
+                original_node=...)],
+            default=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=Constant(
+              value=False,
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='nicknames_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='nickname_set',
+              original_node=...),
+            value=FunctionCall(
+              name='set',
+              args=[],
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Set',
+                original_node=...),
+              index=Name(
+                identifier='str',
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          For(
+            generator=ForEach(
+              variable=Name(
+                identifier='item',
+                original_node=...),
+              iteration=Name(
+                identifier='items',
+                original_node=...),
+              original_node=...),
+            body=[
+              Assignment(
+                target=Name(
+                  identifier='nickname',
+                  original_node=...),
+                value=Member(
+                  instance=Name(
+                    identifier='item',
+                    original_node=...),
+                  name='nickname',
+                  original_node=...),
+                annotation=None,
+                original_node=...),
+              If(
+                branches=[
+                  IfBranch(
+                    condition=IsNone(
+                      value=Name(
+                        identifier='nickname',
+                        original_node=...),
+                      original_node=...),
+                    body=[
+                      Continue(
+                        original_node=...)],
+                    original_node=...)],
+                default=None,
+                original_node=...),
+              If(
+                branches=[
+                  IfBranch(
+                    condition=IsIn(
+                      member=Name(
+                        identifier='nickname',
+                        original_node=...),
+                      container=Name(
+                        identifier='nickname_set',
+                        original_node=...),
+                      original_node=...),
+                    body=[
+                      Return(
+                        value=Constant(
+                          value=False,
+                          original_node=...),
+                        original_node=...)],
+                    original_node=...)],
+                default=None,
+                original_node=...),
+              ExpressionStatement(
+                expression=MethodCall(
+                  member=Member(
+                    instance=Name(
+                      identifier='nickname_set',
+                      original_node=...),
+                    name='add',
+                    original_node=...),
+                  args=[
+                    Name(
+                      identifier='nickname',
+                      original_node=...)],
+                  original_node=...),
+                original_node=...)],
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=Constant(
+              value=True,
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='levels_of_special_items_are_positive',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          For(
+            generator=ForEach(
+              variable=Name(
+                identifier='item',
+                original_node=...),
+              iteration=Name(
+                identifier='items',
+                original_node=...),
+              original_node=...),
+            body=[
+              If(
+                branches=[
+                  IfBranch(
+                    condition=IsInstance(
+                      value=Name(
+                        identifier='item',
+                        original_node=...),
+                      classes=[
+                        Name(
+                          identifier='Special_item',
+                          original_node=...)],
+                      original_node=...),
+                    body=[
+                      If(
+                        branches=[
+                          IfBranch(
+                            condition=Comparison(
+                              left=Member(
+                                instance=Name(
+                                  identifier='item',
+                                  original_node=...),
+                                name='level',
+                                original_node=...),
+                              op='LE',
+                              right=Constant(
+                                value=0,
+                                original_node=...),
+                              original_node=...),
+                            body=[
+                              Return(
+                                value=Constant(
+                                  value=False,
+                                  original_node=...),
+                                original_node=...)],
+                            original_node=...)],
+                        default=None,
+                        original_node=...)],
+                    original_node=...)],
+                default=None,
+                original_node=...)],
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=Constant(
+              value=True,
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='last_is_special',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          If(
+            branches=[
+              IfBranch(
+                condition=Comparison(
+                  left=FunctionCall(
+                    name='len',
+                    args=[
+                      Name(
+                        identifier='items',
+                        original_node=...)],
+                    original_node=...),
+                  op='EQ',
+                  right=Constant(
+                    value=0,
+                    original_node=...),
+                  original_node=...),
+                body=[
+                  Return(
+                    value=Constant(
+                      value=False,
+                      original_node=...),
+                    original_node=...)],
+                original_node=...)],
+            default=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='last',
+              original_node=...),
+            value=Index(
+              collection=Name(
+                identifier='items',
+                original_node=...),
+              index=Sub(
+                left=FunctionCall(
+                  name='len',
+                  args=[
+                    Name(
+                      identifier='items',
+                      original_node=...)],
+                  original_node=...),
+                right=Constant(
+                  value=1,
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Final',
+                original_node=...),
+              index=Name(
+                identifier='Item',
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          If(
+            branches=[
+              IfBranch(
+                condition=IsInstance(
+                  value=Name(
+                    identifier='last',
+                    original_node=...),
+                  classes=[
+                    Name(
+                      identifier='Special_item',
+                      original_node=...)],
+                  original_node=...),
+                body=[
+                  Return(
+                    value=Comparison(
+                      left=Member(
+                        instance=Name(
+                          identifier='last',
+                          original_node=...),
+                        name='level',
+                        original_node=...),
+                      op='GT',
+                      right=Constant(
+                        value=0,
+                        original_node=...),
+                      original_node=...),
+                    original_node=...)],
+                original_node=...)],
+            default=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=Constant(
+              value=False,
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='names_are_disjoint',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='other_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Some_item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='shared_name',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='str',
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=All(
+              generator=ForEach(
+                variable=Name(
+                  identifier='item',
+                  original_node=...),
+                iteration=Name(
+                  identifier='items',
+                  original_node=...),
+                original_node=...),
+              condition=All(
+                generator=ForEach(
+                  variable=Name(
+                    identifier='other_item',
+                    original_node=...),
+                  iteration=Name(
+                    identifier='other_items',
+                    original_node=...),
+                  original_node=...),
+                condition=Or(
+                  values=[
+                    Comparison(
+                      left=Member(
+                        instance=Name(
+                          identifier='item',
+                          original_node=...),
+                        name='name',
+                        original_node=...),
+                      op='NE',
+                      right=Member(
+                        instance=Name(
+                          identifier='other_item',
+                          original_node=...),
+                        name='name',
+                        original_node=...),
+                      original_node=...),
+                    Comparison(
+                      left=Member(
+                        instance=Name(
+                          identifier='item',
+                          original_node=...),
+                        name='name',
+                        original_node=...),
+                      op='EQ',
+                      right=Name(
+                        identifier='shared_name',
+                        original_node=...),
+                      original_node=...)],
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='aliased_names_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='optional_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Optional',
+            subscripts=[
+              SubscriptedTypeAnnotation(
+                identifier='Sequence',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Item',
+                    node=...)],
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='alias',
+              original_node=...),
+            value=Name(
+              identifier='items',
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Final',
+                original_node=...),
+              index=Index(
+                collection=Name(
+                  identifier='Sequence',
+                  original_node=...),
+                index=Name(
+                  identifier='Item',
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='alias_of_alias',
+              original_node=...),
+            value=Name(
+              identifier='alias',
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Final',
+                original_node=...),
+              index=Index(
+                collection=Name(
+                  identifier='Sequence',
+                  original_node=...),
+                index=Name(
+                  identifier='Item',
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='optional_alias',
+              original_node=...),
+            value=Name(
+              identifier='optional_items',
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Final',
+                original_node=...),
+              index=Index(
+                collection=Name(
+                  identifier='Optional',
+                  original_node=...),
+                index=Index(
+                  collection=Name(
+                    identifier='Sequence',
+                    original_node=...),
+                  index=Name(
+                    identifier='Item',
+                    original_node=...),
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          For(
+            generator=ForEach(
+              variable=Name(
+                identifier='item',
+                original_node=...),
+              iteration=Name(
+                identifier='alias',
+                original_node=...),
+              original_node=...),
+            body=[
+              If(
+                branches=[
+                  IfBranch(
+                    condition=IsInstance(
+                      value=Name(
+                        identifier='item',
+                        original_node=...),
+                      classes=[
+                        Name(
+                          identifier='Special_item',
+                          original_node=...)],
+                      original_node=...),
+                    body=[
+                      If(
+                        branches=[
+                          IfBranch(
+                            condition=Comparison(
+                              left=Member(
+                                instance=Name(
+                                  identifier='item',
+                                  original_node=...),
+                                name='level',
+                                original_node=...),
+                              op='LE',
+                              right=Constant(
+                                value=0,
+                                original_node=...),
+                              original_node=...),
+                            body=[
+                              Return(
+                                value=Constant(
+                                  value=False,
+                                  original_node=...),
+                                original_node=...)],
+                            original_node=...)],
+                        default=None,
+                        original_node=...)],
+                    original_node=...)],
+                default=None,
+                original_node=...)],
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=And(
+              values=[
+                All(
+                  generator=ForEach(
+                    variable=Name(
+                      identifier='item',
+                      original_node=...),
+                    iteration=Name(
+                      identifier='alias_of_alias',
+                      original_node=...),
+                    original_node=...),
+                  condition=Comparison(
+                    left=FunctionCall(
+                      name='len',
+                      args=[
+                        Member(
+                          instance=Name(
+                            identifier='item',
+                            original_node=...),
+                          name='name',
+                          original_node=...)],
+                      original_node=...),
+                    op='GT',
+                    right=Constant(
+                      value=0,
+                      original_node=...),
+                    original_node=...),
+                  original_node=...),
+                FunctionCall(
+                  name='names_are_unique',
+                  args=[
+                    Name(
+                      identifier='alias_of_alias',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='optional_names_are_unique',
+                  args=[
+                    Name(
+                      identifier='optional_alias',
+                      original_node=...)],
+                  original_node=...),
+                Or(
+                  values=[
+                    IsNone(
+                      value=Name(
+                        identifier='optional_alias',
+                        original_node=...),
+                      original_node=...),
+                    FunctionCall(
+                      name='names_are_unique',
+                      args=[
+                        Name(
+                          identifier='optional_alias',
+                          original_node=...)],
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='contains_some_item',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='some_item',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='Some_item',
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=IsIn(
+              member=Name(
+                identifier='some_item',
+                original_node=...),
+              container=Name(
+                identifier='items',
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='items_overlap',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='other_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Some_item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=Any(
+              generator=ForEach(
+                variable=Name(
+                  identifier='other_item',
+                  original_node=...),
+                iteration=Name(
+                  identifier='other_items',
+                  original_node=...),
+                original_node=...),
+              condition=IsIn(
+                member=Name(
+                  identifier='other_item',
+                  original_node=...),
+                container=Name(
+                  identifier='items',
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='contains_special_item',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='special_item',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='Special_item',
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Special_item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=IsIn(
+              member=Name(
+                identifier='special_item',
+                original_node=...),
+              container=Name(
+                identifier='items',
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='container_names_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='container',
+          type_annotation=AtomicTypeAnnotation(
+            identifier='Container',
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='some_items',
+              original_node=...),
+            value=Member(
+              instance=Name(
+                identifier='container',
+                original_node=...),
+              name='some_items',
+              original_node=...),
+            annotation=None,
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Assignment(
+            target=Name(
+              identifier='all_some_items',
+              original_node=...),
+            value=Member(
+              instance=Name(
+                identifier='container',
+                original_node=...),
+              name='some_items',
+              original_node=...),
+            annotation=Index(
+              collection=Name(
+                identifier='Final',
+                original_node=...),
+              index=Index(
+                collection=Name(
+                  identifier='Sequence',
+                  original_node=...),
+                index=Name(
+                  identifier='Some_item',
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)"""),
+        textwrap.dedent("""\
+          Return(
+            value=And(
+              values=[
+                FunctionCall(
+                  name='names_are_unique',
+                  args=[
+                    Name(
+                      identifier='some_items',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='names_are_unique',
+                  args=[
+                    Name(
+                      identifier='all_some_items',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='optional_names_are_unique',
+                  args=[
+                    Name(
+                      identifier='all_some_items',
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='optional_names_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Optional',
+            subscripts=[
+              SubscriptedTypeAnnotation(
+                identifier='Sequence',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Item',
+                    node=...)],
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=Or(
+              values=[
+                IsNone(
+                  value=Name(
+                    identifier='items',
+                    original_node=...),
+                  original_node=...),
+                FunctionCall(
+                  name='names_are_unique',
+                  args=[
+                    Name(
+                      identifier='items',
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='some_names_are_unique',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='some_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Some_item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...),
+        Argument(
+          name='special_items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Optional',
+            subscripts=[
+              SubscriptedTypeAnnotation(
+                identifier='Sequence',
+                subscripts=[
+                  AtomicTypeAnnotation(
+                    identifier='Special_item',
+                    node=...)],
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=And(
+              values=[
+                FunctionCall(
+                  name='names_are_unique',
+                  args=[
+                    Name(
+                      identifier='some_items',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='optional_names_are_unique',
+                  args=[
+                    Name(
+                      identifier='some_items',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='optional_names_are_unique',
+                  args=[
+                    Name(
+                      identifier='special_items',
+                      original_node=...)],
+                  original_node=...),
+                FunctionCall(
+                  name='optional_names_are_unique',
+                  args=[
+                    Constant(
+                      value=None,
+                      original_node=...)],
+                  original_node=...),
+                Or(
+                  values=[
+                    IsNone(
+                      value=Name(
+                        identifier='special_items',
+                        original_node=...),
+                      original_node=...),
+                    FunctionCall(
+                      name='names_are_unique',
+                      args=[
+                        Name(
+                          identifier='special_items',
+                          original_node=...)],
+                      original_node=...)],
+                  original_node=...)],
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...),
+    UnderstoodMethod(
+      name='levels_are_positive',
+      verification=True,
+      visibility='PUBLIC',
+      arguments=[
+        Argument(
+          name='items',
+          type_annotation=SubscriptedTypeAnnotation(
+            identifier='Sequence',
+            subscripts=[
+              AtomicTypeAnnotation(
+                identifier='Special_item',
+                node=...)],
+            node=...),
+          default=None,
+          node=...)],
+      returns=AtomicTypeAnnotation(
+        identifier='bool',
+        node=...),
+      description=Description(
+        document=...,
+        node=...),
+      contracts=Contracts(
+        preconditions=[],
+        snapshots=[],
+        postconditions=[]),
+      non_mutating=False,
+      body=[
+        textwrap.dedent("""\
+          Return(
+            value=All(
+              generator=ForEach(
+                variable=Name(
+                  identifier='item',
+                  original_node=...),
+                iteration=Name(
+                  identifier='items',
+                  original_node=...),
+                original_node=...),
+              condition=Comparison(
+                left=Member(
+                  instance=Name(
+                    identifier='item',
+                    original_node=...),
+                  name='level',
+                  original_node=...),
+                op='GT',
+                right=Constant(
+                  value=0,
+                  original_node=...),
+                original_node=...),
+              original_node=...),
+            original_node=...)""")],
+      node=...,
+      arguments_by_name=...)],
+  meta_model=MetaModel(
+    description=Description(
+      document=...,
+      node=...),
+    version='dummy',
+    xml_namespace='https://dummy.com'))
\ No newline at end of file
diff --git a/dev/tests/intermediate/test_type_inference.py b/dev/tests/intermediate/test_type_inference.py
index cfe0d18c3..ee59a7462 100644
--- a/dev/tests/intermediate/test_type_inference.py
+++ b/dev/tests/intermediate/test_type_inference.py
@@ -4808,6 +4808,37 @@ def some_func(numbers: List[int]) -> bool:
         )
 
 
+_COLLECTION_INVARIANCE_EXPLANATION: Final[str] = (
+    "The lists and the sets are invariant, so their items need to be of exactly "
+    "the same type. A mutable List[...] can not hold the instances of a subclass, "
+    "since the callee could insert an instance of another subclass into it. Only "
+    "a read-only Sequence[...] argument of a verification function accepts "
+    "the instances of a subclass, since the targets with invariant lists declare "
+    "it generic: Go with a type parameter, C++ with a template, C# with "
+    "IReadOnlyList<T> and Java with List<? extends T>. The methods can not accept "
+    "them, since Go methods can not have type parameters, and C++ virtual methods "
+    "can not be templates. We do not copy the list implicitly either, as that "
+    "would cost linear time and memory on each call. Please declare the argument "
+    "with the exact type of the items."
+)
+
+
+def _generic_sequence_explanation(name: str) -> str:
+    return (
+        f"The argument {name!r} is a read-only Sequence[...] of a class with "
+        f"descendants, so the targets declare it generic to accept the sequences "
+        f"of the descendants without a copy: Go with a type parameter, C++ with "
+        f"a template, C# with IReadOnlyList<T>, and Java with List<? extends T>. "
+        f"Hence, we support it only as the collection of a for-loop or of "
+        f"all/any, the collection of an index, the container of in, the argument "
+        f"of len, the value of a nullness check, an argument of a verification "
+        f"function, and the value of an immutable alias of the very same type, "
+        f"*e.g.*, ``alias: Final[Sequence[...]] = {name}``. Elsewhere, *e.g.*, "
+        f"passed to a method, assigned to a mutable variable or copied with list, "
+        f"the targets would expect the non-generic list."
+    )
+
+
 _SET_PRELUDE: Final[
     str
 ] = """\
@@ -4835,6 +4866,286 @@ def collect(text: str, texts: Set[str]) -> bool:
 """
 
 
+class Test_invariant_list_arguments(unittest.TestCase):
+    @staticmethod
+    def source_with_verification(verification: str) -> str:
+        return f"""\
+class Abstract_item(DBC):
+    @implementation_specific
+    @non_mutating
+    def count(self, items: Sequence["Abstract_item"]) -> int:
+        pass
+
+
+class Some_item(Abstract_item):
+    def __init__(self) -> None:
+        pass
+
+
+@verification
+def check(items: Sequence[Abstract_item]) -> bool:
+    return len(items) > 0
+
+
+@verification
+def fill(items: List[Abstract_item]) -> bool:
+    return len(items) > 0
+
+
+@verification
+@implementation_specific
+def check_specifically(items: Sequence[Abstract_item]) -> bool:
+    pass
+
+
+@verification
+@implementation_specific
+def check_optional_specifically(items: Optional[Sequence[Abstract_item]]) -> bool:
+    pass
+
+
+@verification
+@implementation_specific
+def fill_specifically(items: List[Abstract_item]) -> bool:
+    pass
+
+
+{verification}
+
+
+__version__ = "dummy"
+__xml_namespace__ = "https://dummy.com"
+"""
+
+    def test_sequence_of_same_items(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: List[Abstract_item]) -> bool:
+    return check(items) and fill(items) and check_specifically(items)"""
+            )
+        )
+
+    def test_sequence_of_descendants_to_implementation_specific(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(
+    items: Sequence[Some_item], optional_items: Optional[Sequence[Some_item]]
+) -> bool:
+    return (
+        check_specifically(items)
+        and check_optional_specifically(items)
+        and check_optional_specifically(optional_items)
+    )"""
+            )
+        )
+
+    def test_sequence_of_descendants_to_transpiled_verification(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Sequence[Some_item]) -> bool:
+    return check(items)"""
+            )
+        )
+
+    def test_supported_usages_of_generic_sequence(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(
+    items: Sequence[Abstract_item], optional_items: Optional[Sequence[Abstract_item]]
+) -> bool:
+    for item in items:
+        if not isinstance(item, Some_item):
+            return False
+
+    if optional_items is not None:
+        if len(optional_items) > 0:
+            return check(optional_items)
+
+    return (
+        len(items) > 0
+        and isinstance(items[0], Some_item)
+        and all(isinstance(item, Some_item) for item in items)
+        and check(items)
+        and check_specifically(items)
+        and check_optional_specifically(optional_items)
+    )"""
+            )
+        )
+
+    def test_generic_sequence_to_method_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(item: Some_item, items: Sequence[Abstract_item]) -> bool:
+    return item.count(items) > 0"""
+            ),
+            expected_joined_message=_generic_sequence_explanation("items"),
+        )
+
+    def test_generic_sequence_assigned_to_variable_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Sequence[Abstract_item]) -> bool:
+    alias: Sequence[Abstract_item] = items
+    return len(alias) > 0"""
+            ),
+            expected_joined_message=_generic_sequence_explanation("items"),
+        )
+
+    def test_immutable_alias_of_generic_sequence(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(
+    items: Sequence[Abstract_item], optional_items: Optional[Sequence[Abstract_item]]
+) -> bool:
+    alias: Final[Sequence[Abstract_item]] = items
+    alias_of_alias: Final[Sequence[Abstract_item]] = alias
+    optional_alias: Final[Optional[Sequence[Abstract_item]]] = optional_items
+    return (
+        all(isinstance(item, Some_item) for item in alias_of_alias)
+        and check(alias)
+        and (optional_alias is None or check(optional_alias))
+    )"""
+            )
+        )
+
+    def test_immutable_alias_of_another_type_fails(self) -> None:
+        # NOTE (mristin):
+        # The optional alias does not share the type annotation of the required
+        # generic sequence, so the targets would need to convert it.
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Sequence[Abstract_item]) -> bool:
+    alias: Final[Optional[Sequence[Abstract_item]]] = items
+    return alias is not None"""
+            ),
+            expected_joined_message=_generic_sequence_explanation("items"),
+        )
+
+    def test_copy_of_immutable_alias_of_generic_sequence_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Sequence[Abstract_item]) -> bool:
+    alias: Final[Sequence[Abstract_item]] = items
+    copy = list(alias)
+    return len(copy) > 0"""
+            ),
+            expected_joined_message=_generic_sequence_explanation("alias"),
+        )
+
+    def test_generic_sequence_copied_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Sequence[Abstract_item]) -> bool:
+    copy = list(items)
+    return len(copy) > 0"""
+            ),
+            expected_joined_message=_generic_sequence_explanation("items"),
+        )
+
+    def test_generic_sequence_as_container_of_in(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(item: Some_item, items: Sequence[Abstract_item]) -> bool:
+    return item in items"""
+            )
+        )
+
+    def test_sequence_without_descendants_is_not_generic(self) -> None:
+        Test_with_smoke.execute(
+            Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(item: Some_item, items: Sequence[Some_item]) -> bool:
+    copy = list(items)
+    return len(copy) > 0"""
+            )
+        )
+
+    def test_mutable_list_of_descendants_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: List[Some_item]) -> bool:
+    return fill(items)"""
+            ),
+            expected_joined_message=(
+                "The argument 'items' of the verification function 'fill' is "
+                "of type List[Abstract_item], but got: List[Some_item]. "
+                + _COLLECTION_INVARIANCE_EXPLANATION
+            ),
+        )
+
+    def test_mutable_list_of_descendants_to_implementation_specific_fails(
+        self,
+    ) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: List[Some_item]) -> bool:
+    return fill_specifically(items)"""
+            ),
+            expected_joined_message=(
+                "The argument 'items' of the verification function "
+                "'fill_specifically' is of type List[Abstract_item], but got: "
+                "List[Some_item]. " + _COLLECTION_INVARIANCE_EXPLANATION
+            ),
+        )
+
+    def test_optional_sequence_of_descendants_to_non_optional_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(items: Optional[Sequence[Some_item]]) -> bool:
+    return check_specifically(items)"""
+            ),
+            expected_joined_message=(
+                "The argument 'items' of the verification function "
+                "'check_specifically' is of type List[Abstract_item], but got: "
+                "Optional[List[Some_item]]. " + _COLLECTION_INVARIANCE_EXPLANATION
+            ),
+        )
+
+    def test_sequence_of_descendants_to_method_fails(self) -> None:
+        Test_with_smoke().expect_type_inference_to_fail(
+            source=Test_invariant_list_arguments.source_with_verification(
+                """\
+@verification
+def some_func(item: Some_item, items: Sequence[Some_item]) -> bool:
+    return item.count(items) > 0"""
+            ),
+            expected_joined_message=(
+                "The argument 'items' of the method 'count' is of type "
+                "List[Abstract_item], but got: List[Some_item]. "
+                + _COLLECTION_INVARIANCE_EXPLANATION
+            ),
+        )
+
+
 class Test_set(unittest.TestCase):
     def expect_type_inference_to_fail(self, body: str, expected_message: str) -> None:
         """Expect the type inference of the verification functions to fail."""
@@ -5160,7 +5471,8 @@ def some_func(number: int) -> bool:
 """,
             expected_message=(
                 "The argument 'texts' of the verification function 'is_in' is of "
-                "type Set[str], but got: Set[int]"
+                "type Set[str], but got: Set[int]. "
+                + _COLLECTION_INVARIANCE_EXPLANATION
             ),
         )
 
@@ -5173,7 +5485,8 @@ def some_func(texts: Sequence[str]) -> bool:
 """,
             expected_message=(
                 "The argument 'texts' of the verification function 'is_in' is of "
-                "type Set[str], but got: List[str]"
+                "type Set[str], but got: List[str]. "
+                + _COLLECTION_INVARIANCE_EXPLANATION
             ),
         )
 
@@ -5801,6 +6114,49 @@ def expect_errors(self, methods: str, expected_messages: List[str]) -> None:
             Test_method.infer(Test_method.source_with_methods(methods)),
         )
 
+    def test_sequence_of_descendants_to_method_fails(self) -> None:
+        # NOTE (mristin):
+        # The arguments of the methods are never generic, since Go methods can not
+        # have type parameters, and C++ virtual methods can not be templates.
+        self.expect_errors(
+            methods="""\
+@non_mutating
+def count_parents(self, parents: Sequence["Parent"]) -> int:
+    return len(parents)
+
+@non_mutating
+def count_children(self, children: Sequence["Child"]) -> int:
+    return self.count_parents(children)""",
+            expected_messages=[
+                "The argument 'parents' of the method 'count_parents' is of type "
+                "List[Parent], but got: List[Child]. "
+                + _COLLECTION_INVARIANCE_EXPLANATION,
+                "The method '__parent_private' of the class 'Child' is private, "
+                "so it can be only called on self from the methods of the class",
+            ],
+        )
+
+    def test_sequence_argument_of_method_is_not_generic(self) -> None:
+        # NOTE (mristin):
+        # The usages of the sequence arguments of the methods are not restricted,
+        # in contrast to the generic sequences of the verification functions, as
+        # the methods take the sequences of the exact items.
+        self.expect_errors(
+            methods="""\
+@non_mutating
+def count_parents(self, parents: Sequence["Parent"]) -> int:
+    return len(parents)
+
+@non_mutating
+def count_copies(self, parents: Sequence["Parent"]) -> int:
+    copies = list(parents)
+    return self.count_parents(parents) + len(copies)""",
+            expected_messages=[
+                "The method '__parent_private' of the class 'Child' is private, "
+                "so it can be only called on self from the methods of the class",
+            ],
+        )
+
     def test_mutating_method_on_self(self) -> None:
         self.expect_errors(
             methods="""\
diff --git a/dev/tests/test_main.py b/dev/tests/test_main.py
index 1dc7e4a56..2bf1dcc68 100644
--- a/dev/tests/test_main.py
+++ b/dev/tests/test_main.py
@@ -471,6 +471,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.CPP, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.CPP,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.CPP, case_name="visibility"
@@ -496,6 +502,12 @@ def test_unexpected_conflict_between_underlying_of_function_and_class(
             case_name="conflict_between_underlying_of_function_and_class",
         )
 
+    def test_unexpected_public_generic_verification_calls_internal(self) -> None:
+        self._run_unexpected_test(
+            target=aas_core_codegen.main.Target.CPP,
+            case_name="public_generic_verification_calls_internal",
+        )
+
 
 class Test_csharp(_TestCase):
     def test_expected_aas_core_meta_v3(self) -> None:
@@ -697,6 +709,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.CSHARP, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.CSHARP,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.CSHARP, case_name="visibility"
@@ -915,6 +933,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.GOLANG, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.GOLANG,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.GOLANG, case_name="visibility"
@@ -1140,6 +1164,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.JAVA, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.JAVA,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.JAVA, case_name="visibility"
@@ -1385,6 +1415,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.JSONSCHEMA, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.JSONSCHEMA,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.JSONSCHEMA, case_name="visibility"
@@ -1591,6 +1627,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.PYTHON, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.PYTHON,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.PYTHON, case_name="visibility"
@@ -1822,6 +1864,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.TYPESCRIPT, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.TYPESCRIPT,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.TYPESCRIPT, case_name="visibility"
@@ -2050,6 +2098,12 @@ def test_expected_unions(self) -> None:
             target=aas_core_codegen.main.Target.XSD, case_name="unions"
         )
 
+    def test_expected_variance_of_containers(self) -> None:
+        self._run_expected_test(
+            target=aas_core_codegen.main.Target.XSD,
+            case_name="variance_of_containers",
+        )
+
     def test_expected_visibility(self) -> None:
         self._run_expected_test(
             target=aas_core_codegen.main.Target.XSD, case_name="visibility"