code: def test_starlette_response_json(serve_instance):
      @serve.deployment
      def json():
          return starlette.responses.JSONResponse({"hello": "world"})
  
      serve.run(json.bind())
      assert (
          requests.get("http://127.0.0.1:8000/json").json()["hello"]
          == "world"
      )
  
imports: import asyncio
  import os
  import sys
  from typing import Dict, Optional
  import pytest
  import requests
  import starlette.responses
  from fastapi import FastAPI
  import ray
  from ray import serve
  from ray._private.pydantic_compat import BaseModel, ValidationError
  from ray._private.test_utils import SignalActor, wait_for_condition
  from ray.serve._private.api import call_app_builder_with_args_if_necessary
  from ray.serve._private.common import DeploymentID
  from ray.serve._private.constants import SERVE_DEFAULT_APP_NAME
  from ray.serve.deployment import Application
  from ray.serve.exceptions import RayServeException
  from ray.serve.handle import DeploymentHandle, RayServeHandle
label_desc: Use image node_id 7 for calling a global function with example usage: test_starlette_response_json(serve_instance) and returns: starlette