code: def test_proxy_state_update_shutting_down():
      """Test calling update method on ProxyState when the proxy state is shutting
      down.
  
      This should be no-op. The status of the http proxy state will not be changed.
      """
      proxy_state = _create_proxy_state()
      previous_status = proxy_state.status
      proxy_state.shutdown()
      proxy_state.update()
      current_status = proxy_state.status
  
      # Ensure the proxy state is in the shutting down state.
      assert proxy_state._shutting_down
  
      # Ensure the status didn't change.
      assert previous_status == current_status
  
imports: import json
  import time
  from typing import List, Tuple
  from unittest.mock import patch
  import pytest
  from ray._private.test_utils import wait_for_condition
  from ray.serve._private.cluster_node_info_cache import ClusterNodeInfoCache
  from ray.serve._private.common import ProxyStatus
  from ray.serve._private.constants import PROXY_HEALTH_CHECK_UNHEALTHY_THRESHOLD
  from ray.serve._private.proxy_state import ProxyState, ProxyStateManager, ProxyWrapper, ProxyWrapperCallStatus
  from ray.serve._private.test_utils import MockTimer
  from ray.serve._private.utils import Timer
  from ray.serve.config import DeploymentMode, HTTPOptions
  from ray.serve.schema import LoggingConfig
label_desc: Use image node_id 9 for calling a global function with example usage: test_proxy_state_update_shutting_down() without return types