code: def queue_size(self):
      return len(self._queue)
  
imports: import asyncio
  from collections import deque
  import logging
  import random
  from typing import Tuple, List
  import grpc
  from ray._private.utils import get_or_create_event_loop
  import ray._private.gcs_utils
  import ray._private.logging_utils
  from ray.core.generated.gcs_pb2 import ErrorTableData
  from ray.core.generated import dependency_pb2
  from ray.core.generated import gcs_service_pb2_grpc
  from ray.core.generated import gcs_service_pb2
  from ray.core.generated import common_pb2
  from ray.core.generated import pubsub_pb2
label_desc: Use image node_id 2 for calling the GcsAioActorSubscriber obj's underlying member method code with example usage: obj.queue_size() and returns: len