@UiHandler("btnGetAllContacts")
 void onGetAllContacts(ClickEvent e) {
   List<String> listItems = acWithImage.getItemValues();
   for (String item : listItems) {
     MaterialToast.alert(item);
   }
 }
 @UiHandler("btnGetAll")
 void onGetAll(ClickEvent e) {
   List<String> listItems = acList.getItemValues();
   for (String item : listItems) {
     MaterialToast.alert(item);
   }
   acWithImage.setError("P");
 }