code: def test_tokenizers():
      try:
          ### test the openai, claude, cohere and llama2 tokenizers.
          ### The tokenizer value should be different for all
          sample_text = "Hellö World, this is my input string!"
  
          # openai tokenizer
          openai_tokens = token_counter(
              model="gpt-3.5-turbo", text=sample_text
          )
  
          # claude tokenizer
          claude_tokens = token_counter(
              model="claude-instant-1", text=sample_text
          )
  
          # cohere tokenizer
          cohere_tokens = token_counter(
              model="command-nightly", text=sample_text
          )
  
          # llama2 tokenizer
          llama2_tokens = token_counter(
              model="meta-llama/Llama-2-7b-chat", text=sample_text
          )
  
          print(
              f"openai tokens: {openai_tokens}; claude tokens: {claude_tokens}; cohere tokens: {cohere_tokens}; llama2 tokens: {llama2_tokens}"
          )
  
          # assert that all token values are different
          assert (
              openai_tokens != cohere_tokens != llama2_tokens
          ), "Token values are not different."
  
          print("test tokenizer: It worked!")
      except Exception as e:
          pytest.fail(f"An exception occured: {e}")
  
file_path: litellm/litellm/tests/test_token_counter.py
imports: import sys, os
  import traceback
  import pytest
  import time
  from litellm import token_counter, encode, decode
label_desc: Use image node_id 2 for calling a global function with example usage: test_tokenizers() without return types