code: def _num_token_from_text(
      text: str, model: str = "gpt-3.5-turbo-0613"
  ):
      """Return the number of tokens used by a string."""
      try:
          encoding = tiktoken.encoding_for_model(model)
      except KeyError:
          logger.warning(
              f"Model {model} not found. Using cl100k_base encoding."
          )
          encoding = tiktoken.get_encoding("cl100k_base")
      return len(encoding.encode(text))
  
file_path: autogen/autogen/token_count_utils.py
imports: from typing import List, Union, Dict
  import logging
  import json
  import tiktoken
  import re
label_desc: Use image node_id 5 for calling a global function with example usage: _num_token_from_text(text, model) and returns: len