@Override
      public void add(@NotNull List<? extends Locale> elements) {
        final List<Locale> currentItems = getItems();
        elements = ContainerUtil.filter(elements,
                                        locale -> !restrictedLocales.contains(locale) && !currentItems.contains(locale));
        super.add(elements);
      }
@Override
      public void add(@NotNull List<? extends Locale> elements)