@Deprecated
  public static <E extends @Nullable Object> Set<E> newSetFromMap(
      Map<E, Boolean> map) {
    return Collections.newSetFromMap(map);
  }

  /**
   * An unmodifiable view of a set which may be backed by other sets; this view will change as the
   * backing sets do. Contains methods to copy the data into a new set which will then remain