def METHOD_NAME(self, chart_command):
    expected = pd.DataFrame(
        {
            "b": [21, 22, 23],
            "c": [31, 32, 33],
        }
    )
    expected.index = pd.RangeIndex(1, 4)
    element = chart_command(DATAFRAME, x="b", y="c")
    element._arrow_add_rows(NEW_ROWS)
    proto = bytes_to_data_frame(
        self.get_delta_from_queue().arrow_add_rows.data.data
    )
    pd.testing.assert_frame_equal(proto, expected)