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();

  /** Poor man's method reference for {@code Deque::addFirst} and {@code Deque::addLast}. */
  private enum InsertionOrder {
    FRONT {
      @Override
      <T> void insertInto(Deque<T> deque, T value) {
        deque.addFirst(value);
      }
    },
    BACK {
      @Override
      <T> void insertInto(Deque<T> deque, T value) {
        deque.addLast(value);
      }
    };

    @Override
    public void addFirst(E e) {
      synchronized (mutex) {
        delegate().addFirst(e);
      }
    }

    @Override
    public void addLast(E e) {
      synchronized (mutex) {
        delegate().addLast(e);
      }
    }

    @Override
    public boolean offerFirst(E e) {
      synchronized (mutex) {
        return delegate().offerFirst(e);
      }
    }

            .createTestSuite());
    suite.addTest(filterSuite());
    suite.addTest(transformSuite());
    return suite;
  }

  static TestSuite filterSuite() {
    TestSuite suite = new TestSuite("Filter");
    suite.addTest(filterMapSuite());
    suite.addTest(filterBiMapSuite());
    suite.addTest(filterSortedMapSuite());
    suite.addTest(filterNavigableMapSuite());
    return suite;
  }

    TestSuite suite = new TestSuite();

    // Not testing rowKeySet() or columnKeySet() of Table.transformValues()
    // since the transformation doesn't affect the row and column key sets.

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {

    TestSuite suite = new TestSuite(name);
    for (Entry<String, String> entry : TEST_STRINGS.entrySet()) {
      if (testAsCharSource) {
        suite.addTest(suiteForString(factory, entry.getValue(), name, entry.getKey()));
      } else {
        suite.addTest(
            suiteForBytes(
                factory, entry.getValue().getBytes(Charsets.UTF_8), name, entry.getKey(), true));
      }
    }
    return suite;
  }

    suite.addTest(
        SetTestSuiteBuilder.using(new ImmutableSetWithBadHashesGenerator())
            .named(ImmutableSetTest.class.getName() + ", with bad hashes")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

    suite.addTest(

            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE);

    TestSuite suite = new TestSuite();
    suite.addTestSuite(CompactHashSetTest.class);
    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {

    TestSuite suite = new TestSuite();
    suite.addTest(createExampleSuite(new ArrayListExample("ArrayList")));
    suite.addTest(createExampleSuite(new LinkedListExample("LinkedList")));
    suite.addTest(createExampleSuite(new ArraysAsListExample("Arrays.asList")));
    suite.addTest(createExampleSuite(new ImmutableListExample("ImmutableList")));
    suite.addTest(createExampleSuite(new CopyOnWriteListExample("CopyOnWriteArrayList")));

            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE);

    TestSuite suite = new TestSuite();
    suite.addTestSuite(CompactHashSetTest.class);
    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {