@UiHandler("daysOfWeek")
 protected void onChange(ChangeEvent event) {
   if (presenter != null) {
     MListBox source = (MListBox) event.getSource();
     presenter.onDayOfWeekSelected(source.getSelectedIndex());
   }
 }
 @Override
 public int getDayOfWeekSelected() {
   return daysOfWeek.getSelectedIndex();
 }