def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def test_impl():
            A = StringArray(['ABC', 'BB', 'ADEF'])
            df = pd.DataFrame({'A': A})
            B = df.A.str.contains('BB', regex=False)
            return B.sum()