// Create form
Form<?> form = new Form<Void>("form");
// Create model of task
AbstractTaskContainer taskContainer = DefaultTaskManager.getInstance().makeContainer(1000L, TimeUnit.MINUTES);
// Create a progress button.
ProgressButton progressButton = new ProgressButton("button", form, Model.of(taskContainer), this, Duration.milliseconds(500L));
progressButton.registerMessageModel(Model.of("Start"), InteractionState.STARTABLE, InteractionState.RESTARTABLE);