class_docstr: Shuffles all the lines in the context.
  
  Context is defined to be any text prepended to the first turn of a conversation, for
  example, personas.
code: def message_mutation(self, message: Message) -> Message:
      texts = message.pop("text").split("\n")
      context, text = texts[:-1], texts[-1]
      self.rng.shuffle(context)
      output = context + [text]
      message["text"] = "\n".join(output)
      return message
  
file_path: ParlAI/parlai/mutators/context_shuffle.py
imports: import random
  from parlai.core.opt import Opt
  from parlai.core.message import Message
  from parlai.core.mutators import register_mutator, MessageMutator
label_desc: Use image node_id 2 for calling the ContextShuffleMutator obj's underlying member method code with example usage: obj.message_mutation(message) and returns: message