code: def message_mutation(self, message: Message) -> Message:
      new_message = message.copy()
      new_message.pop("knowledge")
      new_docs = [" ".join(message["knowledge"].split("\n"))]
      new_titles = [""]
      new_urls = [""]
      new_message.force_set(CONST.RETRIEVED_DOCS, new_docs)
      new_message.force_set(CONST.RETRIEVED_DOCS_TITLES, new_titles)
      new_message.force_set(CONST.RETRIEVED_DOCS_URLS, new_urls)
      return new_message
  
imports: from parlai.core.mutators import register_mutator, MessageMutator, ManyEpisodeMutator
  from parlai.core.message import Message
  import parlai.tasks.wizard_of_internet.constants
  import random
label_desc: Use image node_id 1 for calling the WowToWoi obj's underlying member method code with example usage: obj.message_mutation(message) and returns: new_message