this.stack = new ArrayDeque<>();
      stack.addLast(expand(root));
    }

    @Override
    @CheckForNull
    protected T computeNext() {
      while (!stack.isEmpty()) {
        PostOrderNode<T> top = stack.getLast();
        if (top.childIterator.hasNext()) {
          T child = top.childIterator.next();
          stack.addLast(expand(child));
        } else {
          stack.removeLast();

  /**
   * Forces the segment containing the given {@code key} to expand (see {@link Segment#expand()}).
   */
  static <K, V> void forceExpandSegment(Cache<K, V> cache, K key) {
    checkNotNull(cache);
    checkNotNull(key);
    LocalCache<K, V> map = toLocalCache(cache);
    int hash = map.hash(key);
    Segment<K, V> segment = map.segmentFor(hash);
    segment.expand();
  }

  /**

      new HashMap<>();

  /**
   * Given a set of features, add to it all the features directly or indirectly implied by any of
   * them, and return it.
   *
   * @param features the set of features to expand
   * @return the same set of features, expanded with all implied features
   */
  @CanIgnoreReturnValue
  public static Set<Feature<?>> addImpliedFeatures(Set<Feature<?>> features) {

    oldValueRef.clear();
    assertNull(segment.put(key, hash, newValue, true));
    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));
  }

  public void testSegmentPut_expand() {
    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().concurrencyLevel(1).initialCapacity(1));
    Segment<Object, Object, ?, ?> segment = map.segments[0];

    oldValueRef.clear();
    assertNull(segment.put(key, hash, newValue, true));
    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));
  }

  public void testSegmentPut_expand() {
    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().concurrencyLevel(1).initialCapacity(1));
    Segment<Object, Object, ?, ?> segment = map.segments[0];

    assertThrows(
        "expected IllegalArgumentException for call to slice with length -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

  // Test that you can not expand the readable data in a previously sliced ByteSource.
  public void testSlice_constrainedRange() throws IOException {
    long size = source.read().length;
    if (size >= 2) {

        else if (n >= NCPU || cells != as) collide = false; // At max size or stale
        else if (!collide) collide = true;
        else if (busy == 0 && casBusy()) {
          try {
            if (cells == as) { // Expand table unless stale
              Cell[] rs = new Cell[n << 1];
              for (int i = 0; i < n; ++i) rs[i] = as[i];
              cells = rs;
            }
          } finally {
            busy = 0;

  /**
   * Forces the segment containing the given {@code key} to expand (see {@link Segment#expand()}).
   */
  static <K, V> void forceExpandSegment(Cache<K, V> cache, K key) {
    checkNotNull(cache);
    checkNotNull(key);
    LocalCache<K, V> map = toLocalCache(cache);
    int hash = map.hash(key);
    Segment<K, V> segment = map.segmentFor(hash);
    segment.expand();
  }

  /**

    assertThrows(
        "expected IllegalArgumentException for call to slice with length -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

  // Test that you can not expand the readable data in a previously sliced ByteSource.
  public void testSlice_constrainedRange() throws IOException {
    long size = source.read().length;
    if (size >= 2) {

        && ipString.charAt(ipString.length() - 2) != IPV6_DELIMITER) {
      return null; // :$ requires ::$
    }
    if (hasSkip && partsSkipped <= 0) {
      return null; // :: must expand to at least one '0'
    }
    if (!hasSkip && delimiterCount + 1 != IPV6_PART_COUNT) {
      return null; // Incorrect number of parts
    }

    ByteBuffer rawBytes = ByteBuffer.allocate(2 * IPV6_PART_COUNT);