code: public static String pingJmsBackoutQueue(MuleContext muleContext, String muleJmsConnectorName, String queueName) {
  	    try {
  	    	if (isQueueEmpty(muleContext, muleJmsConnectorName, queueName)) {
  	    	    return OK_PREFIX + ": The queue " + queueName + " in the queue manager " + muleJmsConnectorName + " is empty"; 
  	    		
  	    	} else {
  	    	    return ERROR_PREFIX + ": The queue " + queueName + " in the queue manager " + muleJmsConnectorName + " is not empty"; 
  	    	}
  	
  	    } catch (JMSException e) {
  		    return ERROR_PREFIX + ": The queue " + queueName + " was not found in the queue manager " + muleJmsConnectorName + ", reason: " + e.getMessage(); 
  	    }	
  	}
docs: Verify access to a JMS backout queue by browsing the backout queue and ensure that no messages exists.
  
  @param muleJmsConnectorName
  @param queueName
  @return