code: def __await__(self):
      future = asyncio.Future()
      future.set_result(self)
      result = yield from future
      if self.called:
          return pickle.dumps(self.messages)
      self.called = True
      return result
  
imports: import asyncio
  import pickle
  import sys
  from typing import Dict
  from unittest.mock import AsyncMock
  import grpc
  import pytest
  import ray
  from ray import serve
  from ray.actor import ActorHandle
  from ray.serve._private.common import DeploymentID, EndpointInfo, EndpointTag
  from ray.serve._private.constants import DEFAULT_UVICORN_KEEP_ALIVE_TIMEOUT_S, SERVE_NAMESPACE
  from ray.serve._private.proxy import DRAINED_MESSAGE, HEALTH_CHECK_SUCCESS_MESSAGE, HTTPProxy, ResponseStatus, gRPCProxy
  from ray.serve._private.proxy_request_response import ProxyRequest
  from ray.serve._private.proxy_router import ProxyRouter
  from ray.serve._private.test_utils import FakeGrpcContext
  from ray.serve.generated import serve_pb2
  from ray.serve.grpc_util import RayServegRPCContext
label_desc: Use image node_id 4 for calling the FakeRef obj's underlying member method code with example usage: obj.__await__() and returns: result, pickle