public void startup(Display display, Map<String, String> properties)
throws Exception {
WTKXSerializer wtkxSerializer = new WTKXSerializer();
wtkxSerializer.put(APPLICATION_KEY, this);
window = (Window)wtkxSerializer.readObject(this, "json_viewer.wtkx");
wtkxSerializer.bind(this);
Label prompt = new Label("Drag or paste JSON here");
prompt.getStyles().put("horizontalAlignment", HorizontalAlignment.CENTER);
prompt.getStyles().put("verticalAlignment", VerticalAlignment.CENTER);