code: def client():
      filepath = os.path.dirname(os.path.abspath(__file__))
      config_fp = f"{filepath}/test_configs/test_bad_config.yaml"
      asyncio.run(initialize(config=config_fp))
      from litellm.proxy.proxy_server import app
  
      return TestClient(app)
  
file_path: litellm/litellm/tests/test_proxy_exception_mapping.py
imports: import sys, os
  from dotenv import load_dotenv
  import os, io, asyncio
  import pytest
  import litellm, openai
  from fastapi.testclient import TestClient
  from fastapi import FastAPI
  from litellm.proxy.proxy_server import router, save_worker_config, initialize
label_desc: Use image node_id 1 for calling a global function with example usage: client() and returns: TestClient