void doIt(ImmutableLongArray.Builder builder, AtomicLong counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override
      void doIt(ImmutableLongArray.Builder builder, AtomicLong counter) {
        long[] array = new long[RANDOM.nextInt(10)];
        for (int i = 0; i < array.length; i++) {
          array[i] = counter.getAndIncrement();
        }
        builder.addAll(array);

      void doIt(ImmutableDoubleArray.Builder builder, AtomicInteger counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override
      void doIt(ImmutableDoubleArray.Builder builder, AtomicInteger counter) {
        double[] array = new double[RANDOM.nextInt(10)];
        for (int i = 0; i < array.length; i++) {
          array[i] = counter.getAndIncrement();
        }

    final AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i = 0; i < SIZE; i++) {
      aa.set(i, (double) COUNTDOWN);
    }
    Counter c1 = new Counter(aa);
    Counter c2 = new Counter(aa);
    Thread t1 = newStartedThread(c1);
    Thread t2 = newStartedThread(c2);
    awaitTermination(t1);
    awaitTermination(t2);
    assertEquals(SIZE * COUNTDOWN, c1.counts + c2.counts);

    final AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i = 0; i < SIZE; i++) {
      aa.set(i, (double) COUNTDOWN);
    }
    Counter c1 = new Counter(aa);
    Counter c2 = new Counter(aa);
    Thread t1 = newStartedThread(c1);
    Thread t2 = newStartedThread(c2);
    awaitTermination(t1);
    awaitTermination(t2);
    assertEquals(SIZE * COUNTDOWN, c1.counts + c2.counts);

    for (int i = 0; i < 1000; i++) {
      final AtomicInteger counter = new AtomicInteger();
      final TrustedListenableFutureTask<Integer> task =
          TrustedListenableFutureTask.create(
              new Callable<Integer>() {
                @Override
                public Integer call() {
                  return counter.incrementAndGet();
                }
              });

  private WorkerRunningState workerRunningState = IDLE;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the
   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be

        }
        long size = spliterator.getExactSizeIfKnown();
        long[] counter = {0};
        spliterator.forEachRemaining(
            e -> {
              consumer.accept(e);
              counter[0]++;
            });
        if (size >= 0) {
          assertEquals(size, counter[0]);
        }
      }
    },
    ALTERNATE_ADVANCE_AND_SPLIT {
      @Override

   * exception is thrown, this exception is used as the result of the output {@code Future}.
   *
   * <p>Usage example:
   *
   * <pre>{@code
   * // Falling back to a zero counter in case an exception happens when processing the RPC to fetch
   * // counters.
   * ListenableFuture<Integer> faultTolerantFuture =
   *     fetchCounters().catching(FetchException.class, x -> 0, directExecutor());

    assertEquals(-1, counter.read(new byte[30]));
    assertEquals(20, counter.getCount());
  }

  @SuppressWarnings("CheckReturnValue") // calling read() to skip a byte
  public void testMark() throws Exception {
    assertTrue(counter.markSupported());
    assertEquals(10, counter.read(new byte[10]));
    assertEquals(10, counter.getCount());
    counter.mark(5);
    counter.read();

  public void testSingleSimpleStats() {
    StatsCounter counter = new SimpleStatsCounter();
    for (int i = 0; i < 11; i++) {
      counter.recordHits(1);
    }
    for (int i = 0; i < 13; i++) {
      counter.recordLoadSuccess(i);
    }
    for (int i = 0; i < 17; i++) {
      counter.recordLoadException(i);
    }
    for (int i = 0; i < 23; i++) {
      counter.recordMisses(1);
    }