public void subscribe() {
String q = "/topic/VirtualTopic.app.event.sensor.object.behavior.change";
//String q= "/queue/test";
if (q != null) {
JSONObject header = new JSONObject();
header.put("transformation", new JSONString("jms-object-xml"));
sc.subscribe(q, new ACStompListener(sc),header.getJavaScriptObject());
//sc.subscribe(q, new ACStompListener(sc));
GWT.log("subscribed to queue " + q);
//Window.alert("subscribed to queue " + q);