*
   * @since 14.0
   */
  public static HashFunction adler32() {
    return ChecksumType.ADLER_32.hashFunction;
  }

  @Immutable
  enum ChecksumType implements ImmutableSupplier<Checksum> {
    CRC_32("Hashing.crc32()") {
      @Override
      public Checksum get() {
        return new CRC32();
      }
    },
    ADLER_32("Hashing.adler32()") {

  private static final long SPIN_THRESHOLD_NANOS = 1000L;

  @VisibleForTesting
  static String atomicHelperTypeForTest() {
    return ATOMIC_HELPER.atomicHelperTypeForTest();
  }

  private enum VarHandleAtomicHelperMaker {
    INSTANCE {
      /**
       * Implementation used by non-J2ObjC environments (aside, of course, from those that have
       * supersource for the entirety of {@link AbstractFutureState}).

        public StatsCounter get() {
          return new SimpleStatsCounter();
        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override

      if (newArg == null || Objects.equals(args.get(i), newArg)) {
        if (params.get(i).getType().getRawType().isEnum()) {
          continue; // Nothing better we can do if it's single-value enum
        }
        throw new ParameterHasNoDistinctValueException(params.get(i));
      }
      newArgs.set(i, newArg);
      tester.addEqualityGroup(createInstance(factory, newArgs));

   * char[])}.
   *
   * @since 2.0
   */
  public static Comparator<char[]> lexicographicalComparator() {
    return LexicographicalComparator.INSTANCE;
  }

  private enum LexicographicalComparator implements Comparator<char[]> {
    INSTANCE;

    @Override
    public int compare(char[] left, char[] right) {
      int minLength = Math.min(left.length, right.length);

   * float[])}.
   *
   * @since 2.0
   */
  public static Comparator<float[]> lexicographicalComparator() {
    return LexicographicalComparator.INSTANCE;
  }

  private enum LexicographicalComparator implements Comparator<float[]> {
    INSTANCE;

    @Override
    public int compare(float[] left, float[] right) {
      int minLength = Math.min(left.length, right.length);

   *
   * @since 2.0
   */
  public static Comparator<int[]> lexicographicalComparator() {
    return LexicographicalComparator.INSTANCE;
  }

  private enum LexicographicalComparator implements Comparator<int[]> {
    INSTANCE;

    @Override
    // A call to bare "min" or "max" would resolve to our varargs method, not to any static import.

   * double[])}.
   *
   * @since 2.0
   */
  public static Comparator<double[]> lexicographicalComparator() {
    return LexicographicalComparator.INSTANCE;
  }

  private enum LexicographicalComparator implements Comparator<double[]> {
    INSTANCE;

    @Override
    public int compare(double[] left, double[] right) {
      int minLength = Math.min(left.length, right.length);

    `http://` schemes.

 *  **RouteDatabase is no longer public API.** OkHttp continues to track which
    routes have failed but this is no exposed in the API.

 *  **ResponseSource is gone.** This enum exposed whether a response came from
    the cache, network, or both. OkHttp 2 offers more detail with raw access to
    the cache and network responses in the new `Response` class.

    this.header = new AvlNode<>();
    successor(header, header);
    this.rootReference = new Reference<>();
  }

  /** A function which can be summed across a subtree. */
  private enum Aggregate {
    SIZE {
      @Override
      int nodeAggregate(AvlNode<?> node) {
        return node.elemCount;
      }

      @Override
      long treeAggregate(@Nullable AvlNode<?> root) {