def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def test_impl():
            df = pq.read_table('example.parquet').to_pandas()
            return (df.two.unique() == 'foo').sum()