def METHOD_NAME(self):
    group1 = Group(domain=DOMAIN, name='group1',
                   users=[self.active_user._id, self.inactive_user._id, self.deleted_user._id])
    group1.save()
    group2 = Group(domain=DOMAIN, name='group2',
                   users=[self.active_user._id, self.inactive_user._id, self.deleted_user._id])
    group2.save()
    group1.remove_user(self.active_user._id)
    group2.remove_user(self.deleted_user._id)
    g1_old_modified = group1.last_modified
    g2_old_modified = group2.last_modified
    Group.bulk_save([group1, group2])
    group1_updated = Group.get(group1.get_id)
    group2_updated = Group.get(group2.get_id)
    self.assertNotEqual(g1_old_modified, group1_updated.last_modified)
    self.assertNotEqual(g2_old_modified, group2_updated.last_modified)