* @since 23.0
   */
  public static ContiguousSet<Long> closed(long lower, long upper) {
    return create(Range.closed(lower, upper), DiscreteDomain.longs());
  }

  /**
   * Returns a contiguous set containing all {@code int} values from {@code lower} (inclusive) to
   * {@code upper} (exclusive). If the endpoints are equal, an empty set is returned. (These are the

   * @since 23.0
   */
  public static ContiguousSet<Long> closed(long lower, long upper) {
    return create(Range.closed(lower, upper), DiscreteDomain.longs());
  }

  /**
   * Returns a contiguous set containing all {@code int} values from {@code lower} (inclusive) to
   * {@code upper} (exclusive). If the endpoints are equal, an empty set is returned. (These are the