public class SimpleExample {

        public static class Event {
            private String eventInfo;

            public Event(String eventInfo) {
                this.eventInfo = eventInfo;
            }

            public String getEventInfo() {
                return eventInfo;
            }
        }

        public static class Listener {

            @Subscribe
            public void printEvent(Event event){
                System.out.println("Something happens: " + event.getEventInfo());
            }
        }

        public static void main(String[] args) {

            // initial setup
            // create event service and listener
            EventService eventService = new AsyncEventService();
            Listener listener = new Listener();
            eventService.subscribe(listener);

            //event publishing
            //results will contain java.util.concurrent.Future that represent notifications
            Collection<NotificationFuture> results = eventService.publish(new Event("Some event"));

            //this will make us wait until all listeners processed event
            for (NotificationFuture future: results) {
                try{
                    future.get();
                }catch (Exception ex){
                    ex.printStackTrace();
                }
            }
        }

    }