code: public synchronized void handleNotification(Notification notification, Object handback) {
          String type = notification.getType();
          if (REGISTRATION_NOTIFICATION.equals(type)) {
              jolokiaMBeanServer = lookupJolokiaMBeanServer();
              // We need to add the listener provided during construction time to add the Jolokia MBeanServer
              // so that it is kept updated, too.
              if (jolokiaMBeanServerListener != null) {
                  JmxUtil.addMBeanRegistrationListener(jolokiaMBeanServer, jolokiaMBeanServerListener, null);
              }
          } else if (UNREGISTRATION_NOTIFICATION.equals(type)) {
              jolokiaMBeanServer = null;
          }
  
          allMBeanServers.clear();
          if (jolokiaMBeanServer != null) {
              allMBeanServers.add(jolokiaMBeanServer);
          }
          allMBeanServers.addAll(detectedMBeanServers);
      }
docs: Fetch Jolokia MBeanServer when it gets registered, remove it if being unregistered
  
  @param notification notification emitted
  @param handback not used here