docs: def process_message(self, message, *args, **kwargs):
          """
          If its level is into persist levels, convert the message to models and save it
          """
          if not message.level in PERSISTENT_MESSAGE_LEVELS:
              return message
  
          user = kwargs.get("user") or self.get_user()
  
          try:
              anonymous = user.is_anonymous()
          except TypeError:
              anonymous = user.is_anonymous
          if anonymous:
              raise NotImplementedError('Persistent message levels cannot be used for anonymous users.')
          message_persistent = PersistentMessage()
          message_persistent.level = message.level
          message_persistent.message = message.message
          message_persistent.extra_tags = message.extra_tags
          message_persistent.user = user
  
          if "expires" in kwargs:
              message_persistent.expires = kwargs["expires"]
          message_persistent.save()
          return None