Premise

Overriding this function to validate Option Group values is allowed. It requires OptionDefinition and OptionResolution:

Problem

The package currently does not export the required OptionResolution (directly or transitively). This problem effectively prevents the import of OptionResolution and consequently prevents the usage of aforementioned functionality in a direct manner, unless having to go through unsustainable practices such as reaching into src/.

Suggestion

May I know whether this is an intentional design choice? If accidental or possible, I reckon OptionResolution can be made public without any breaking changes because it's already marked final. It works via my local dependency after adding merely one line in that export file:

export 'option_resolution.dart';