docs: public static void main(String[] args) {
          JmxDemo demo=new JmxDemo();
          demo.addNotificationListener((notification, handback) -> System.out.println(">> " + notification + ", handback=" + handback), null, "myHandback");
          demo.startNotifications();
  
          MBeanServer server=Util.getMBeanServer();
          if(server != null) {
              try {
                  JmxConfigurator.register(demo, server, "demo:name=DemoObject");
                  while(true) {
                      Util.sleep(10000);
                  }
              }
              catch(Exception e) {
                  e.printStackTrace();
              }
          }
      }