code: def make_reply(self):
          
          return Message(
              to=str(self.sender),
              sender=str(self.to),
              body=self.body,
              thread=self.thread,
              metadata=self.metadata
          )
docs: Creates a copy of the message, exchanging sender and receiver
  
          Returns:
            spade.message.Message: a new message with exchanged sender and receiver