def METHOD_NAME() -> None:
    def fn(a: Iterable[int], b: Optional[Iterable[int]]) -> None:
        pass
    model = SignatureModel.create(
        dependency_name_set=set(),
        fn=fn,
        data_dto=None,
        parsed_signature=ParsedSignature.from_fn(fn, {}),
        type_decoders=[],
    )
    assert model._fields["a"].is_non_string_iterable
    assert model._fields["b"].is_non_string_iterable