def METHOD_NAME(self):
    m = MeetingFactory(type_id='ietf', date=date_today() - datetime.timedelta(days=10))
    cached_groups = GroupFactory.create_batch(2)
    m.cached_groups_at_the_time = {g.pk: g for g in cached_groups}  # fake the cache
    uncached_group_hist = GroupHistoryFactory(time=datetime_today() - datetime.timedelta(days=30))
    self.assertEqual(m.group_at_the_time(uncached_group_hist.group), uncached_group_hist)
    self.assertIn(uncached_group_hist.group.pk, m.cached_groups_at_the_time)