code: def test_token_counter():
      try:
          messages = [
              {
                  "role": "user",
                  "content": "hi how are you what time is it",
              }
          ]
          tokens = token_counter(
              model="gpt-3.5-turbo", messages=messages
          )
          print("gpt-35-turbo")
          print(tokens)
          assert tokens > 0
  
          tokens = token_counter(model="claude-2", messages=messages)
          print("claude-2")
          print(tokens)
          assert tokens > 0
  
          tokens = token_counter(
              model="palm/chat-bison", messages=messages
          )
          print("palm/chat-bison")
          print(tokens)
          assert tokens > 0
  
          tokens = token_counter(
              model="ollama/llama2", messages=messages
          )
          print("ollama/llama2")
          print(tokens)
          assert tokens > 0
  
          tokens = token_counter(
              model="anthropic.claude-instant-v1", messages=messages
          )
          print("anthropic.claude-instant-v1")
          print(tokens)
          assert tokens > 0
      except Exception as e:
          pytest.fail(f"Error occurred: {e}")
  
imports: import sys, os
  from dotenv import load_dotenv
  import copy
  import os
  import pytest
  import litellm
  from litellm.utils import trim_messages, get_token_count, get_valid_models, check_valid_key, validate_environment, function_to_dict, token_counter
label_desc: Use image node_id 15 for calling a global function with example usage: test_token_counter() without return types