def METHOD_NAME():
    # We deliberately setup a situation where two Dataset subclasses
    # that aren't parents are consisdered valid.
    # We implement the bare minimum for these classes to be actually
    # loadable in order to test hints.
    class MockHierarchy(GridIndex):
        pass
    class MockDataset(Dataset):
        _index_class = MockHierarchy
        def _parse_parameter_file(self, *args, **kwargs):
            self.current_time = -1.0
            self.cosmological_simulation = 0
        def _set_code_unit_attributes(self, *args, **kwargs):
            self.length_unit = self.quan(1, "m")
            self.mass_unit = self.quan(1, "kg")
            self.time_unit = self.quan(1, "s")
        @classmethod
        def _is_valid(cls, *args, **kwargs):
            return True
    class AlphaDataset(MockDataset):
        @classmethod
        def _is_valid(cls, *args, **kwargs):
            return True
    class BetaDataset(MockDataset):
        @classmethod
        def _is_valid(cls, *args, **kwargs):
            return True
    yield
    # teardown to avoid possible breakage in following tests
    output_type_registry.pop("MockDataset")
    output_type_registry.pop("AlphaDataset")
    output_type_registry.pop("BetaDataset")