code: public void handleServerNotificationRegistration(RESTRequest request, int clientID, ServerNotificationRegistration serverNotificationRegistration,
                                                       JSONConverter converter) {
          //Get the client area
          ClientNotificationArea clientArea = getInboxIfAvailable(clientID, converter);
  
          if (serverNotificationRegistration.operation == Operation.RemoveAll) {
              //Unregister with our client area (will also unregister with the MBeanServer)
              clientArea.removeServerNotificationListener(request, serverNotificationRegistration, true, converter, false);
  
          } else {
              if (serverNotificationRegistration.operation == Operation.Add) {
                  //Register with our client area (will also register with the MBeanServer)
                  clientArea.addServerNotificationListener(request, serverNotificationRegistration, converter);
  
                  if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                      Tr.debug(tc, "Added server-side notification");
                  }
  
              } else {
                  //Unregister with our client area (will also unregister with the MBeanServer)
                  clientArea.removeServerNotificationListener(request, serverNotificationRegistration, false, converter, false);
              }
          }
      }
docs: Handle a server notification registration.
  This method is only invoked by our java client.