class_docstr: Mutator that add the bot failure text in text (with special tokens surrounded)
class_docstr_tok: ["Mutator","that","add","the","bot","failure","text","in","text","(","with","special","tokens","surrounded",")"]
code: def message_mutation(self, message: Message) -> Message:
      if "bot_failure_text" in message:
          new_message = message.copy()
          new_message.force_set(
              "text",
              message["text"]
              + f"\n{self.TOKEN_BOT_FAILURE} {normalize_reply(new_message['bot_failure_text'])} {self.TOKEN_BOT_FAILURE_END}",
          )
          return new_message
  
      return message
  
imports: from string import punctuation
  import copy
  from typing import List
  from parlai.core.mutators import register_mutator, ManyEpisodeMutator, MessageMutator
  from parlai.core.message import Message
  from parlai.mutators.flatten import FlattenMutator
  from parlai.utils.strings import normalize_reply
  from parlai.tasks.wizard_of_wikipedia.agents import TOKEN_KNOWLEDGE, TOKEN_END_KNOWLEDGE
  from parlai.tasks.wizard_of_internet import constants
  from .constants import FeedbackType, UNWANTED_TOKENS
label_desc: Use image node_id 1 for calling the BotFailureSpecialToken obj's underlying member method code with example usage: obj.message_mutation(message) and returns: message, new_message