def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def add_item(self, item_value=None, index=None):
    if item_value is None:
      item_value = self._new_item_default_value