def dispatch_notification(self, msg):
        """dispatch register/unregister events."""
        try:
            idents,msg = self.session.feed_identities(msg)
        except ValueError:
            self.log.warn("task::Invalid Message: %r",msg)
            return
        try:
            msg = self.session.unserialize(msg)
        except ValueError:
            self.log.warn("task::Unauthorized message from: %r"%idents)
            return

        msg_type = msg['header']['msg_type']

        handler = self._notification_handlers.get(msg_type, None)
        if handler is None:
            self.log.error("Unhandled message type: %r"%msg_type)
        else:
            try:
                handler(cast_bytes(msg['content']['queue']))
            except Exception:
                self.log.error("task::Invalid notification msg: %r", msg, exc_info=True)