private void addFrozenItems(Set<? extends LookupElement> items, LinkedHashSet<? super LookupElement> model) {
    myFrozenItems.removeIf(element -> !element.isValid() || !items.contains(element));
    model.addAll(myFrozenItems);
  }
private void addFrozenItems(Set<? extends LookupElement> items, LinkedHashSet<? super LookupElement> model)