<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def handle_message(self, message):
 """Handle a message received off of the underlying consumer. If the message has an eta, delay it. Otherwise, put it on the work queue. """

        try:
            if "eta" in message.options:
                self.logger.debug("Pushing message %r onto delay queue.", message.message_id)
                self.broker.emit_before("delay_message", message)
                self.delay_queue.put((message.options.get("eta", 0), message))

            else:
                actor = self.broker.get_actor(message.actor_name)
                self.logger.debug("Pushing message %r onto work queue.", message.message_id)
                self.work_queue.put((actor.priority, message))
        except ActorNotFound:
            self.logger.error(
                "Received message for undefined actor %r. Moving it to the DLQ.",
                message.actor_name, exc_info=True,
            )
            message.fail()
            self.post_process_message(message)