def set_mask_key(self, func):
        self.get_mask_key = func
Raises a BadRequestError that says the given entity groups are different.
dataset/ETHPy150Open tomwilkie/awesomation/third_party/py/websocket-client/websocket.py/WebSocket.set_mask_key--crossover with--dataset/ETHPy150Open CollabQ/CollabQ/.google_appengine/google/appengine/api/datastore.py/_DifferentEntityGroupError