diff --git a/Sources/TranslationCatalogIO/KeyHierarchy.swift b/Sources/TranslationCatalogIO/KeyHierarchy.swift
index 555ca7a..3c79cf8 100644
--- a/Sources/TranslationCatalogIO/KeyHierarchy.swift
+++ b/Sources/TranslationCatalogIO/KeyHierarchy.swift
@@ -75,10 +75,24 @@ public struct KeyHierarchy {
         self.nodes = nodes
     }
 
-    public static func make(with expressions: [TranslationCatalog.Expression]) throws -> KeyHierarchy {
+    public static func make(with localizationKeys: [LocalizationKey]) throws -> KeyHierarchy {
         var hierarchy = KeyHierarchy()
 
-        try expressions
+        try localizationKeys.forEach { key in
+            let id = key.key
+                .components(separatedBy: String(key.strategy.separator))
+                .map {
+                    [$0]
+                }
+
+            try hierarchy.processKey(key, path: id)
+        }
+
+        return hierarchy
+    }
+
+    public static func make(with expressions: [TranslationCatalog.Expression]) throws -> KeyHierarchy {
+        let localizationKeys = try expressions
             .map {
                 try LocalizationKey(
                     key: $0.key,
@@ -86,17 +100,8 @@ public struct KeyHierarchy {
                     comment: $0.context
                 )
             }
-            .forEach { key in
-                let id = key.key
-                    .components(separatedBy: String(key.strategy.separator))
-                    .map {
-                        [$0]
-                    }
-
-                try hierarchy.processKey(key, path: id)
-            }
 
-        return hierarchy
+        return try make(with: localizationKeys)
     }
 
     mutating func processKey(_ key: LocalizationKey, path: KeyNodePath) throws {
@@ -116,9 +121,10 @@ public struct KeyHierarchy {
         }
 
         guard !components.isEmpty else {
-            if let token = Self.reservedTypeTokens.first(where: { $0.caseInsensitiveCompare(component) == .orderedSame }) {
-                throw HierarchyError.reservedTypeToken(token)
-            }
+            // Since this is the last token, it will become a `enum case`; No need to block here?!
+            // if let token = Self.reservedTypeTokens.first(where: { $0.caseInsensitiveCompare(component) == .orderedSame }) {
+            //     throw HierarchyError.reservedTypeToken(token)
+            // }
 
             if Int(component) != nil {
                 throw HierarchyError.reservedType(Int.self)
diff --git a/Tests/TranslationCatalogTests/KeyHierarchy2Tests.swift b/Tests/TranslationCatalogTests/KeyHierarchy2Tests.swift
index c5342f3..a3e5dd0 100644
--- a/Tests/TranslationCatalogTests/KeyHierarchy2Tests.swift
+++ b/Tests/TranslationCatalogTests/KeyHierarchy2Tests.swift
@@ -5,60 +5,42 @@ import XCTest
 
 final class KeyHierarchy2Tests: XCTestCase {
 
-    let expressions: [TranslationCatalog.Expression] = [
-        Expression(
-            id: UUID(uuidString: "0681BB4E-A63F-4E3C-AA15-5E152844B7EC")!,
+    let keys: [LocalizationKey] = [
+        LocalizationKey(
             key: "PAYMENT_METHOD_ADD_ACTION",
-            value: "Add payment method",
-            languageCode: .english
+            defaultValue: "Add payment method"
         ),
-        Expression(
-            id: UUID(uuidString: "B7FA5A95-2FE5-4887-8619-566CDA83F23E")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_ADD_CARD_FAILURE_MESSAGE",
-            value: "Your payment method could not be added at this time.",
-            languageCode: .english
+            defaultValue: "Your payment method could not be added at this time."
         ),
-        Expression(
-            id: UUID(uuidString: "76C37D84-8AF3-4011-88B1-BCC80B2D6C6A")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_ADD_CARD_SUCCESS_MESSAGE",
-            value: "Your payment method has been added.",
-            languageCode: .english
+            defaultValue: "Your payment method has been added."
         ),
-        Expression(
-            id: UUID(uuidString: "52B6650F-F041-4CA3-ACE6-38E7930D026D")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_CONFIRM_DELETE",
-            value: "Are you sure you want to delete this payment method?",
-            languageCode: .english
+            defaultValue: "Are you sure you want to delete this payment method?"
         ),
-        Expression(
-            id: UUID(uuidString: "943D6EF9-A37A-4BB6-8C93-05FECAD1DA8C")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_EXPIRATION_ABBREVIATION",
-            value: "Exp",
-            languageCode: .english
+            defaultValue: "Exp"
         ),
-        Expression(
-            id: UUID(uuidString: "95C73B79-8111-43E7-85AC-EF4C74586594")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_NAVIGATION_TITLE",
-            value: "Manage Payments",
-            languageCode: .english
+            defaultValue: "Manage Payments"
         ),
-        Expression(
-            id: UUID(uuidString: "E5792937-3C63-4C10-8B58-0E405E76AB56")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_REMOVE_CARD_FAILURE_MESSAGE",
-            value: "Your payment method could not be deleted at this time.",
-            languageCode: .english
+            defaultValue: "Your payment method could not be deleted at this time."
         ),
-        Expression(
-            id: UUID(uuidString: "185CA880-88DB-4CA6-98A4-FD544B908900")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_REMOVE_CARD_SUCCESS_MESSAGE",
-            value: "Your payment method has been deleted.",
-            languageCode: .english
+            defaultValue: "Your payment method has been deleted."
         ),
-        Expression(
-            id: UUID(uuidString: "9E141C73-8D8C-40B6-AF56-AFD94C230752")!,
+        LocalizationKey(
             key: "PAYMENT_METHOD_SECTION_TITLE",
-            value: "Payment Methods",
-            languageCode: .english
+            defaultValue: "Payment Methods"
         ),
     ]
 
@@ -66,7 +48,7 @@ final class KeyHierarchy2Tests: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
-        hierarchy = try KeyHierarchy.make(with: expressions)
+        hierarchy = try KeyHierarchy.make(with: keys)
     }
 
     func testHierarchyGeneration() throws {
diff --git a/Tests/TranslationCatalogTests/KeyHierarchyTests.swift b/Tests/TranslationCatalogTests/KeyHierarchyTests.swift
index 186769c..e125196 100644
--- a/Tests/TranslationCatalogTests/KeyHierarchyTests.swift
+++ b/Tests/TranslationCatalogTests/KeyHierarchyTests.swift
@@ -5,54 +5,38 @@ import XCTest
 
 final class KeyHierarchyTests: XCTestCase {
 
-    let expressions: [TranslationCatalog.Expression] = [
-        Expression(
-            id: UUID(uuidString: "0681BB4E-A63F-4E3C-AA15-5E152844B7EC")!,
+    let keys: [LocalizationKey] = [
+        LocalizationKey(
             key: "GREETING",
-            value: "Hello World!",
-            languageCode: .english
+            defaultValue: "Hello World!"
         ),
-        Expression(
-            id: UUID(uuidString: "B7FA5A95-2FE5-4887-8619-566CDA83F23E")!,
+        LocalizationKey(
             key: "APPLICATION_NAME",
-            value: "Lingua",
-            languageCode: .english
+            defaultValue: "Lingua"
         ),
-        Expression(
-            id: UUID(uuidString: "76C37D84-8AF3-4011-88B1-BCC80B2D6C6A")!,
+        LocalizationKey(
             key: "HIDDEN_MESSAGE",
-            value: "",
-            languageCode: .english
+            defaultValue: ""
         ),
-        Expression(
-            id: UUID(uuidString: "52B6650F-F041-4CA3-ACE6-38E7930D026D")!,
+        LocalizationKey(
             key: "PLATFORM_ANDROID",
-            value: "Android",
-            languageCode: .english
+            defaultValue: "Android"
         ),
-        Expression(
-            id: UUID(uuidString: "943D6EF9-A37A-4BB6-8C93-05FECAD1DA8C")!,
+        LocalizationKey(
             key: "PLATFORM_APPLE",
-            value: "Apple",
-            languageCode: .english
+            defaultValue: "Apple"
         ),
-        Expression(
-            id: UUID(uuidString: "95C73B79-8111-43E7-85AC-EF4C74586594")!,
+        LocalizationKey(
             key: "PLATFORM_APPLE_MAC",
-            value: "macOS",
-            languageCode: .english
+            defaultValue: "macOS"
         ),
-        Expression(
-            id: UUID(uuidString: "E5792937-3C63-4C10-8B58-0E405E76AB56")!,
+        LocalizationKey(
             key: "PLATFORM_WEB",
-            value: "Web",
-            languageCode: .english
+            defaultValue: "Web"
         ),
-        Expression(
-            id: UUID(uuidString: "185CA880-88DB-4CA6-98A4-FD544B908900")!,
+        LocalizationKey(
             key: "ZULU_TIME_DEFINITION",
-            value: "definition",
-            languageCode: .english
+            defaultValue: "definition"
         ),
     ]
 
@@ -60,7 +44,7 @@ final class KeyHierarchyTests: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
-        hierarchy = try KeyHierarchy.make(with: expressions)
+        hierarchy = try KeyHierarchy.make(with: keys)
     }
 
     func testHierarchyGeneration() throws {