class_docstr: Uses the checked sentence (knowledge) as label.
class_docstr_tok: ["Uses","the","checked","sentence","(","knowledge",")","as","label","."]
code: def message_mutation(self, message: Message) -> Message:
      new_message = message.copy()
      if (
          "text" not in message
          or "labels" not in message
          or not message["labels"]
      ):
          return message
      labels = new_message.pop("labels")
      checked_sentence = new_message.get(
          self.checked_sentence_kword, ""
      )
      if isinstance(checked_sentence, list):
          checked_sentence = " ".join(checked_sentence)
  
      new_message["dialogue_response"] = labels
      new_message["labels"] = [checked_sentence]
      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 2 for calling the CheckedSentenceAsLabel obj's underlying member method code with example usage: obj.message_mutation(message) and returns: new_message, message