protected void notifyItemsSelected() {
   for (ItemPickerListener<ItemT> listener : listeners) {
     listener.onItemsSelected(getPickerId(), getSelectedIndices());
   }
 }
 protected void notifyDialogCancelled() {
   for (ItemPickerListener<ItemT> listener : listeners) {
     listener.onCancelled(getPickerId());
   }
 }