code: def save_prompt(self):
      if self.sep_style == SeparatorStyle.ADD_BOS_EOS_TOKEN:
          ret = self.system
          for role, message in self.messages:
              if message:
                  ret += role + ": " + "<s>" + message + "</s>\n"
              else:
                  ret += role + ": " + "<s>"
          return ret
      else:
          raise ValueError(f"Invalid style: {self.sep_style}")
  
file_path: colossalai/applications/ColossalEval/colossal_eval/utils/conversation.py
imports: import dataclasses
  from enum import Enum, auto
  from typing import Dict, List, Optional, Tuple
  from transformers import AutoTokenizer
label_desc: Use image node_id 4 for calling the Conversation obj's underlying member method code with example usage: obj.save_prompt() and returns: ret