code: def message(self, username, message_text):
          
          # Try to reply to an existing thread.
          if not isinstance(username, six.string_types):
              username = username.username
          for mailbox in (self.inbox, self.outbox):
              for thread in mailbox:
                  if thread.correspondent.lower() == username.lower():
                      thread.reply(message_text)
                      return
  
          return self._message_sender.send(username, message_text)
docs: Message an okcupid user. If an existing conversation between the
          logged in user and the target user can be found, reply to that thread
          instead of starting a new one.
  
          :param username: The username of the user to which the message should
                           be sent.
          :type username: str
          :param message_text: The body of the message.
          :type message_text: str