code: def test_proxy_state_check_health_always_timeout():
      """Test calling update method on ProxyState when the proxy state is HEALTHY and
      when the ready call always timed out and health check timeout and period equals.
  
      The proxy state started with STARTING. After update is called and ready call
      succeeded, the status will change to HEALTHY. After the next few check_health calls
      never finishes and always pending, the status will eventually change to UNHEALTHY
      after all retries have exhausted.
      """
  
      proxy_state = _create_proxy_state()
      proxy_state._actor_proxy_wrapper.health = (
          ProxyWrapperCallStatus.PENDING
      )
  
      # Continuously trigger update. The status should change from STARTING to HEALTHY
      # when ready.
      wait_for_condition(
          condition_predictor=_update_and_check_proxy_status,
          state=proxy_state,
          status=ProxyStatus.HEALTHY,
      )
      first_check_time = proxy_state._last_health_check_time
  
      # Continuously trigger update and status should change to UNHEALTHY.
      wait_for_condition(
          condition_predictor=_update_and_check_proxy_status,
          state=proxy_state,
          status=ProxyStatus.UNHEALTHY,
      )
  
      # Ensure the check time have changed since the last update
      assert first_check_time != proxy_state._last_health_check_time
  
      # Ensure _consecutive_health_check_failures is correct
      assert proxy_state._consecutive_health_check_failures == 3
  
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 18 for calling a global function with example usage: test_proxy_state_check_health_always_timeout() without return types