class Listener1Assist implements ListenerAssist,
        ListenerModelHandler.ModelCreator<Listener1Assist.Listener1Model> {

    public void taskStart(DownloadTask task) {
        final Listener1Model model = modelHandler.addAndGetModel(task, null);
        if (callback != null) callback.taskStart(task, model);
    }

    public  Listener1Assist();
      Listener1Assist(ListenerModelHandler<Listener1Model> handler);

}