code: def test_completion_palm_stream():
      # litellm.set_verbose = True
      model_name = "palm/chat-bison"
      try:
          response = completion(
              model=model_name,
              messages=messages,
              stop=["stop"],
              stream=True,
              max_tokens=20,
          )
          # Add any assertions here to check the response
          for chunk in response:
              print(chunk)
      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 56 for calling a global function with example usage: test_completion_palm_stream() without return types