def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def memoized(*args):
        try:
            return stored_results[args]
        except KeyError:
            result = stored_results[args] = fn(*args)
            return result