code: def test_completion_openai_litellm_key():
      try:
          litellm.set_verbose = True
          litellm.num_retries = 0
          litellm.api_key = os.environ["OPENAI_API_KEY"]
  
          # ensure key is set to None in .env and in openai.api_key
          os.environ["OPENAI_API_KEY"] = ""
          import openai
  
          openai.api_key = ""
          ##########################################################
  
          response = completion(
              model="gpt-3.5-turbo",
              messages=messages,
              temperature=0.5,
              top_p=0.1,
              max_tokens=10,
              user="ishaan_dev@berri.ai",
          )
          # Add any assertions here to check the response
          print(response)
  
          ###### reset environ key
          os.environ["OPENAI_API_KEY"] = litellm.api_key
  
          ##### unset litellm var
          litellm.api_key = None
      except Timeout as e:
          pass
      except Exception as e:
          pytest.fail(f"Error occurred: {e}")
  
imports: import sys, os
  import traceback
  from dotenv import load_dotenv
  import os, io
  import pytest
  import litellm
  from litellm import embedding, completion, completion_cost, Timeout
  from litellm import RateLimitError
  import openai
label_desc: Use image node_id 21 for calling a global function with example usage: test_completion_openai_litellm_key() without return types