docs: public String[] getItemsSelected() {
          List<String> selected = new LinkedList<>();
          for (int i = getIndexOffset(); i < listBox.getItemCount(); i++) {
              if (listBox.isItemSelected(i)) {
                  selected.add(listBox.getValue(i));
              }
          }
          return selected.toArray(new String[selected.size()]);
      }