def METHOD_NAME(self):
    with weewx.manager.open_manager_with_config(self.config_dict, 'wx_binding') as db_manager:
        vt = weewx.xtypes.ArchiveTable.get_aggregate('wind',
                                                     month_timespan,
                                                     'vecavg',
                                                     db_manager)
    self.assertAlmostEqual(vt[0], 8.13691, 5)
    self.assertEqual(vt[1], 'mile_per_hour', 'group_speed')