code: def client() -> ServeControllerClient:
      serve.start()
      yield _get_global_client()
  
imports: import asyncio
  import sys
  from copy import deepcopy
  from typing import Dict, Optional
  import pytest
  import ray
  from ray import serve
  from ray._private.pydantic_compat import BaseModel
  from ray._private.test_utils import SignalActor, wait_for_condition
  from ray.exceptions import RayActorError
  from ray.serve import Application
  from ray.serve._private.client import ServeControllerClient
  from ray.serve._private.common import ApplicationStatus, DeploymentStatus, DeploymentStatusTrigger, ReplicaState, TargetCapacityDirection
  from ray.serve._private.constants import SERVE_DEFAULT_APP_NAME, SERVE_NAMESPACE
  from ray.serve.config import AutoscalingConfig
  from ray.serve.context import _get_global_client
  from ray.serve.schema import ServeApplicationSchema, ServeDeploySchema
label_desc: Use image node_id 3 for calling a global function with example usage: client() without return types