code: public static void main(String[] args){
  
          // Listeners are subscribed by passing them to the #subscribe() method
          bus.subscribe(new ListenerDefinition.SyncAsyncListener());
  
          // #subscribe() is idem-potent => Multiple calls to subscribe do NOT add the listener more than once (set semantics)
          Object listener = new ListenerDefinition.SyncAsyncListener();
          bus.subscribe(listener);
          bus.subscribe(listener);
  
          // Classes without handlers will be silently ignored
          bus.subscribe(new Object());
          bus.subscribe(new String());
  
          bus.publishAsync(new File("/tmp/random.csv")); //returns immediately, publication will continue asynchronously
          bus.post(new File("/tmp/random.csv")).asynchronously(); // same as above
  
          bus.publish("some message");   // will return after each handler has been invoked
          bus.post("some message").now(); // same as above
  
  
      }
docs: this is used for identification in #toString