* @param h hash code
   */
  static int rehash(int h) {
    // Spread bits to regularize both segment and index locations,
    // using variant of single-word Wang/Jenkins hash.
    // TODO(kevinb): use Hashing/move this to Hashing?
    h += (h << 15) ^ 0xffffcd7d;
    h ^= (h >>> 10);
    h += (h << 3);
    h ^= (h >>> 6);
    h += (h << 2) + (h << 14);
    return h ^ (h >>> 16);
  }

  /**

    while (head != null) {
      Listener tmp = head;
      head = head.next;
      tmp.next = reversedList;
      reversedList = tmp;
    }
    return reversedList;
  }

  // TODO(user): move parts into a default method on ListenableFuture?
  @Override
  public String toString() {
    // TODO(cpovirk): Presize to something plausible?
    StringBuilder builder = new StringBuilder();

 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *

    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the
   * comparator has a more general type than the map's keys, such as creating a {@code
   * SortedMap<Integer, String>} with a {@code Comparator<Number>}, use the {@link Builder}
   * constructor instead.
   *

    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the
   * comparator has a more general type than the map's keys, such as creating a {@code
   * SortedMap<Integer, String>} with a {@code Comparator<Number>}, use the {@link Builder}
   * constructor instead.
   *

        Maps.uniqueIndex(
            INT_TO_STRING_MAP.values().iterator(), Functions.forMap(INT_TO_STRING_MAP.inverse()));
    assertEquals(INT_TO_STRING_MAP, outputMap);
  }

  /** Can't create the map if more than one value maps to the same key. */
  public void testUniqueIndexDuplicates() {
    try {
      Map<Integer, String> unused =
          Maps.uniqueIndex(ImmutableSet.of("one", "uno"), Functions.constant(1));

        Maps.uniqueIndex(
            INT_TO_STRING_MAP.values().iterator(), Functions.forMap(INT_TO_STRING_MAP.inverse()));
    assertEquals(INT_TO_STRING_MAP, outputMap);
  }

  /** Can't create the map if more than one value maps to the same key. */
  public void testUniqueIndexDuplicates() {
    try {
      Map<Integer, String> unused =
          Maps.uniqueIndex(ImmutableSet.of("one", "uno"), Functions.constant(1));

   *
   * <p>This method has no effect (returns {@code this}) when called in GWT: it's unclear whether a
   * precomputed matcher is faster, but it certainly consumes more memory, which doesn't seem like a
   * worthwhile tradeoff in a browser.
   */
  public CharMatcher precomputed() {
    return Platform.precomputeCharMatcher(this);
  }

   *
   * @param set the set of elements to construct a power set from
   * @return the power set, as an immutable set of immutable sets
   * @throws IllegalArgumentException if {@code set} has more than 30 unique elements (causing the
   *     power set size to exceed the {@code int} range)
   * @throws NullPointerException if {@code set} is or contains {@code null}

 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *