def testUpdatePermissions(self):
    follower_dict = {'user_id': 1,
                     'viewpoint_id': 'vp1',
                     'labels': [Follower.ADMIN]}
    follower = self.UpdateDBObject(Follower, **follower_dict)
    self.assertRaises(PermissionError, follower.SetLabels, [])
Try to update permission labels to the empty set.
dataset/ETHPy150Open viewfinderco/viewfinder/backend/db/test/follower_test.py/FollowerTestCase.testUpdatePermissions