* set of the empty set is not the empty set, but a one-element set containing the empty set.
   *
   * <p>The returned set and its constituent sets use {@code equals} to decide whether two elements
   * are identical, even if the input set uses a different concept of equivalence.
   *
   * <p><i>Performance notes:</i> while the power set of a set with size {@code n} is of size {@code

   */
  public static CharMatcher inRange(char startInclusive, char endInclusive) {
    return new InRange(startInclusive, endInclusive);
  }

  /**
   * Returns a matcher with identical behavior to the given {@link Character}-based predicate, but
   * which operates on primitive {@code char} instances instead.
   */
  public static CharMatcher forPredicate(Predicate<? super Character> predicate) {

 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *
 * These two URLs are semantically identical, but `java.net.URI` disagrees:
 *
 *  * http://host:80/
 *
 *  * http://host
 *
 * Both the unnecessary port specification (`:80`) and the absent trailing slash (`/`) cause URI to