@classmethod
def debug(cls, message):
    """Called to log debug messages.

        :param str message: A message of some sort.

        :return: None - any returned value is ignored.

        This method doesn't have much of a use.  It's just a way for
        :class:`~syncrepl_client.Syncrepl` to log debug messages.  There's no
        guarantee that you'll get anything meaningful, or anything at all.

        The safest thing to do is to just `pass` this method.  Or, subclass
        :class:`~syncrepl_client.callbacks.BaseCallback`.
        """
    pass
