def METHOD_NAME(self):
    while True:
        message_id = str(uuid.uuid4().hex)
        if message_id not in self.cache:
            self.cache[message_id] = time.time()
            break
    data = pickle.dumps(
        {'type': 'system', 'id': message_id, 'data': 'HELLO'}
    )
    self.send(data)