// the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {
      throwable = cause;
      causes.add(throwable);

      if (throwable == slowPointer) {

    // the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {
      throwable = cause;
      causes.add(throwable);

      if (throwable == slowPointer) {

  private long currentTimeNanos() {
    return ticker.read();
  }

  private void alertListenerIfPresent(K key, V value, RemovalCause cause) {
    if (removalListener != null) {
      removalListener.onRemoval(RemovalNotification.create(key, value, cause));
    }
  }

  @SuppressWarnings("GoodTime") // timestamps as numeric primitives
  private V load(K key) throws ExecutionException {

    for (int i = 0; i < stimuli.length; i++) {
      try {
        stimuli[i].executeAndCompare(reference, target);
        verify(reference.getElements());
      } catch (AssertionFailedError cause) {
        Helpers.fail(cause, "failed with stimuli " + subListCopy(stimuli, i + 1));
      }
    }
  }

  private static List<Object> subListCopy(Object[] source, int size) {
    final Object[] copy = new Object[size];

  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(
      Supplier<T> delegate, Duration duration) {
    checkNotNull(delegate);
    // The alternative of `duration.compareTo(Duration.ZERO) > 0` causes J2ObjC trouble.
    checkArgument(
        !duration.isNegative() && !duration.isZero(), "duration (%s) must be > 0", duration);
    return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }

   * Queue#isEmpty} and {@link Queue#remove()}, since {@link Queue}'s iteration order is undefined.
   * Calling {@link Iterator#hasNext()} on a generated iterator from the returned iterable may cause
   * an item to be immediately dequeued for return on a subsequent call to {@link Iterator#next()}.
   *
   * <p>Whether the input {@code iterable} is a {@link Queue} or not, the returned {@code Iterable}

     * called.
     */
    @CanIgnoreReturnValue
    public Builder<C> addAll(RangeSet<C> ranges) {
      return addAll(ranges.asRanges());
    }

    /**
     * Add all of the specified ranges to this builder. Adjacent ranges are permitted and will be
     * merged, but overlapping ranges will cause an exception when {@link #build()} is called.

     * called.
     */
    @CanIgnoreReturnValue
    public Builder<C> addAll(RangeSet<C> ranges) {
      return addAll(ranges.asRanges());
    }

    /**
     * Add all of the specified ranges to this builder. Adjacent ranges are permitted and will be
     * merged, but overlapping ranges will cause an exception when {@link #build()} is called.

    for (int i = 0; i < stimuli.length; i++) {
      try {
        stimuli[i].executeAndCompare(reference, target);
        verify(reference.getElements());
      } catch (AssertionFailedError cause) {
        Helpers.fail(cause, "failed with stimuli " + subListCopy(stimuli, i + 1));
      }
    }
  }

  private static List<Object> subListCopy(Object[] source, int size) {
    final Object[] copy = new Object[size];

    mmHeap.remove(4);
    try {
      it.next();
      fail("No exception thrown when iterating a modified heap");
    } catch (ConcurrentModificationException expected) {
    }
  }

  /** Tests a failure caused by fix to childless uncle issue. */
  public void testIteratorRegressionChildlessUncle() {
    final ArrayList<Integer> initial = Lists.newArrayList(1, 15, 13, 8, 9, 10, 11, 14);