/**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse
   * of their natural ordering.
   */
  public static <E extends Comparable<?>> Builder<E> reverseOrder() {
    return new Builder<>(Collections.reverseOrder());
  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by their

   */
  public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
    return new Builder<>(comparator);
  }

  /**
   * Returns a builder that creates immutable sorted multisets whose elements are ordered by the
   * reverse of their natural ordering.
   *
   * <p>Note: the type parameter {@code E} extends {@code Comparable<?>} rather than {@code
   * Comparable<? super E>} as a workaround for javac <a