* @return a new, empty {@code CopyOnWriteArraySet}
   * @since 12.0
   */
  @J2ktIncompatible
  @GwtIncompatible // CopyOnWriteArraySet
  public static <E extends @Nullable Object> CopyOnWriteArraySet<E> newCopyOnWriteArraySet() {
    return new CopyOnWriteArraySet<>();
  }

  /**
   * Creates a {@code CopyOnWriteArraySet} instance containing the given elements.
   *