GenericTypeWrapperFactory typedef
GEN-079: Factory callback for creating typed wrappers.
Takes the raw unwrapped value and the inner type argument string
(e.g., 'Color?' for WidgetStateProperty<Color?>).
Returns a properly typed wrapper, or null if the type arg is not supported.
Implementation
typedef GenericTypeWrapperFactory =
Object? Function(Object value, String innerTypeArg);