@Override
  public void onListChanged(final List<String> urls) {
    final String value = myRepositoriesList.getSelectedValue();
    myRepositoriesList.removeAll();
    myRepositoriesList.setListData(ArrayUtil.toStringArray(urls));
    // for keeping selection
    if (value != null) {
      final ListModel<String> model = myRepositoriesList.getModel();
      for (int i = 0; i < model.getSize(); i++) {
        final String element = model.getElementAt(i);
        if (value.equals(element)) {
          myRepositoriesList.setSelectedIndex(i);
        }
      }
    }
    // in order to check for groups ambiguity + maybe highlight another error
    myValidator.run();
  }
@Override
  public void onListChanged(final List<String> urls)