def _structure_frozenset(self, obj, cl):
        """Convert an iterable into a potentially generic frozenset."""
        if is_bare(cl) or cl.__args__[0] is Any:
            return frozenset(obj)
        else:
            elem_type = cl.__args__[0]
            dispatch = self._structure_func.dispatch
            return frozenset(dispatch(elem_type)(e, elem_type) for e in obj)
Convert an iterable into a potentially generic frozenset.