text: """Provide the MessageableMixin class."""
  from ....const import API_PATH
  
  
  class MessageableMixin:
      """Interface for classes that can be messaged."""
  
      def message(self, subject, message, from_subreddit=None):
          """
          Send a message to a redditor or a subreddit's moderators (mod mail).
  
          :param subject: The subject of the message.
          :param message: The message content.
          :param from_subreddit: A Subreddit instance or string to send the
              message from. When provided, messages are sent from the subreddit
              rather than from the authenticated user. Note that the
              authenticated user must be a moderator of the subreddit and have
              mail permissions.
  
          For example, to send a private message to ``/u/spez``, try:
  
          .. code:: python
  
             reddit.redditor('spez').message('TEST', 'test message from PRAW')
  
          To send a message to ``u/spez`` from the moderators of ``r/test`` try:
  
          .. code:: python
  
             reddit.redditor('spez').message('TEST', 'test message from r/test',
                                             from_subreddit='test')
  
          To send a message to the moderators of ``/r/test``, try:
  
          .. code:: python
  
             reddit.subreddit('test').message('TEST', 'test PM from PRAW')
  
          """
          data = {
              "subject": subject,
              "text": message,
              "to": "{}{}".format(
                  getattr(self.__class__, "MESSAGE_PREFIX", ""), self
              ),
          }
          if from_subreddit:
              data["from_sr"] = str(from_subreddit)
          self._reddit.post(API_PATH["compose"], data=data)
  