code: @Override
  	public void handleReturn(
  			int replyCode,
  			String replyText,
  			String exchange,
  			String routingKey,
  			BasicProperties properties,
  			byte[] body )
  	throws IOException {
  
  		String messageType = "undetermined";
  		try {
  			Message msg = SerializationUtils.deserializeObject( body );
  			messageType = msg.getClass().getName();
  
  		} catch( Exception e ) {
  			this.logger.severe( "Failed to deserialize a message object." );
  			Utils.logException( this.logger, e );
  		}
  
  		if( this.logger.isLoggable( Level.WARNING )) {
  			final StringBuilder sb = new StringBuilder();
  			sb.append("A message sent by a RabbitMQ client was not received by any queue.\n");
  			sb.append("Message type: " + messageType + '\n');
  			sb.append("Routing key: " + routingKey + '\n');
  			sb.append("Reason: " + replyText);
  			this.logger.warning( sb.toString());
  		}
  	}
docs: /* (non-Javadoc)
  @see com.rabbitmq.client.ReturnListener
  #handleReturn(int, java.lang.String, java.lang.String, java.lang.String, com.rabbitmq.client.AMQP.BasicProperties, byte[])