code: @Override
      public void onReceive(Object message) throws Exception {
          final Class<?> klass = message.getClass();
          final ActorRef self = self();
          final ActorRef sender = sender();
          final State state = fsm.state();
  
          if(logger.isInfoEnabled()) {
              logger.info("********** Conference Controller Current State: \"" + state.toString());
              logger.info("********** Conference Controller Processing Message: \"" + klass.getName() + " sender : "
                  + sender.getClass());
          }
  
          if (Observe.class.equals(klass)) {
              onObserve((Observe) message, self, sender);
          } else if (StopObserving.class.equals(klass)) {
              onStopObserving((StopObserving) message, self, sender);
          } else if (CreateMediaSession.class.equals(klass)) {
              onCreateMediaSession((CreateMediaSession) message, self, sender);
          } else if (Stop.class.equals(klass)) {
              onStop((Stop) message, self, sender);
          } else if (StopMediaGroup.class.equals(klass)) {
              onStopMediaGroup((StopMediaGroup) message, self, sender);
          } else if (JoinCall.class.equals(klass)) {
              onJoinCall((JoinCall) message, self, sender);
          } else if (Play.class.equals(klass)) {
              onPlay((Play) message, self, sender);
          }
      }
docs: /*
  EVENTS