code: def test_chat_completion(client_no_auth):
      global headers
      try:
          # Your test data
          test_data = {
              "model": "gpt-3.5-turbo",
              "messages": [
                  {"role": "user", "content": "hi"},
              ],
              "max_tokens": 10,
          }
  
          print("testing proxy server with chat completions")
          response = client_no_auth.post(
              "/v1/chat/completions", json=test_data
          )
          print(f"response - {response.text}")
          assert response.status_code == 200
          result = response.json()
          print(f"Received response: {result}")
      except Exception as e:
          pytest.fail(
              f"LiteLLM Proxy test failed. Exception - {str(e)}"
          )
  
imports: import sys, os
  import traceback
  from dotenv import load_dotenv
  import os, io
  import pytest, logging, asyncio
  import litellm
  from litellm import embedding, completion, completion_cost, Timeout
  from litellm import RateLimitError
  from fastapi.testclient import TestClient
  from fastapi import FastAPI
  from litellm.proxy.proxy_server import router, save_worker_config, initialize
  from litellm.integrations.custom_logger import CustomLogger
  from litellm.proxy.proxy_server import ProxyConfig
label_desc: Use image node_id 2 for calling a global function with example usage: test_chat_completion(client_no_auth) without return types