When varying option values, one possibility should be that the option is not given.
This can be represented for string and choice options by allowing '' (empty string) in the set of values, and treating that specially. For integer options, something else is needed.
When varying option values, one possibility should be that the option is not given.
This can be represented for string and choice options by allowing '' (empty string) in the set of values, and treating that specially. For integer options, something else is needed.