code: def _get_or_create_subscription(self):
          
          topic_path = self._get_topic_path()
          subscription_name = '{}-{}-{}-worker'.format(
              queue.PUBSUB_OBJECT_PREFIX, self.name, uuid4().hex)
          subscription_path = self.subscriber_client.subscription_path(
              self.project, subscription_name)
  
          try:
              self.subscriber_client.get_subscription(subscription_path)
          except google.cloud.exceptions.NotFound:
              logger.info("Creating worker subscription {}".format(
                  subscription_name))
              self.subscriber_client.create_subscription(
                  subscription_path, topic_path)
  
          return subscription_path
docs: In a broadcast queue, workers have a unique subscription ensuring
          that every worker recieves a copy of every task.