*
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific choice of
   * hash code unspecified, unlike the Java 8+ equivalent.
   */
  @Override
  public abstract int hashCode();

  /**
   * Returns a string representation for this instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific string

   * input bit(i) and output bit(j), two pairs of keys must be found with all bits identical except
   * bit(i). One pair must differ in output bit(j), and one pair must not. This proves that input
   * bit(i) can alter output bit(j).
   */
  static void checkNoFunnels(HashFunction function) {
    Random rand = new Random(0);
    int keyBits = 32;
    int hashBits = function.bits();

    final List<Integer> completeLengthChecks;
    final int baseStackDepth;
    ExecutorService service = Executors.newFixedThreadPool(5);
    try {
      // Avoid counting frames from the executor itself, or the ExecutionSequencer
      baseStackDepth =
          serializer
              .submit(
                  new Callable<Integer>() {
                    @Override

    final List<Integer> completeLengthChecks;
    final int baseStackDepth;
    ExecutorService service = Executors.newFixedThreadPool(5);
    try {
      // Avoid counting frames from the executor itself, or the ExecutionSequencer
      baseStackDepth =
          serializer
              .submit(
                  new Callable<Integer>() {
                    @Override

          && Modifier.isPublic(method.getModifiers()) // only the public methods
          && method.getParameterTypes().length == 0 // only the seed-less grapes^W hash functions
          && !legacyHashingMethodNames.contains(method.getName())) {
        HashFunction hashFunction = (HashFunction) method.invoke(Hashing.class);
        assertTrue(

   * input bit(i) and output bit(j), two pairs of keys must be found with all bits identical except
   * bit(i). One pair must differ in output bit(j), and one pair must not. This proves that input
   * bit(i) can alter output bit(j).
   */
  static void checkNoFunnels(HashFunction function) {
    Random rand = new Random(0);
    int keyBits = 32;
    int hashBits = function.bits();

              <logLevel>${gwt.logLevel}</logLevel>
              <mode>htmlunit</mode>
              <htmlunit>FF38</htmlunit>
              <productionMode>true</productionMode>
              <!-- Fix OutOfMemoryError under Travis. -->
              <extraJvmArgs>-Xms3500m -Xmx3500m -Xss1024k</extraJvmArgs>
              <sourceLevel>1.8</sourceLevel>

   * Supports-Loading-Mode}</a> header field name. This can be used to specify, for example, <a
   * href="https://developer.chrome.com/docs/privacy-sandbox/fenced-frame/#server-opt-in">fenced
   * frames</a>.
   *
   * @since 32.0.0
   */
  public static final String SUPPORTS_LOADING_MODE = "Supports-Loading-Mode";

  /**
   * The HTTP <a href="http://tools.ietf.org/html/rfc6797#section-6.1">{@code