@NotNull
  @Unmodifiable
  public List<Bookmark> getValidBookmarks() {
    List<Bookmark> answer = ContainerUtil.filter(myBookmarks.values(), b -> b.isValid());
    if (UISettings.getInstance().getSortBookmarks()) {
      return ContainerUtil.sorted(answer);
    }
    else {
      return ContainerUtil.sorted(answer, Comparator.comparingInt(b -> b.index));
    }
  }
@NotNull
  @Unmodifiable
  public List<Bookmark> getValidBookmarks()