Recursive bool

	// ReportNotFound will return errFileNotFound if all disks reports the BaseDir cannot be found.
	ReportNotFound bool

	// FilterPrefix will only return results with given prefix within folder.
	// Should never contain a slash.
	FilterPrefix string

	// ForwardTo will forward to the given object path.
	ForwardTo string

	// Limit the number of returned objects if > 0.
	Limit int

      @CheckForNull T holder = null;

      @Override
      public void accept(@ParametricNullness T t) {
        this.holder = t;
      }

      @Override
      public boolean tryAdvance(Consumer<? super T> action) {
        while (fromSpliterator.tryAdvance(this)) {
          try {
            // The cast is safe because tryAdvance puts a T into `holder`.

	}

	if err := DB.Create(&data).Error; err != nil {
		t.Fatalf("No error should happened when create scanner valuer struct, but got %v", err)
	}

	var result ScannerValuerStruct

	if err := DB.Find(&result, "id = ?", data.ID).Error; err != nil {
		t.Fatalf("no error should happen when query scanner, valuer struct, but got %v", err)
	}

	if result.ExampleStructPtr.Val != "value2" {

    final Map<Path, Holder> modelByPath = new ConcurrentHashMap<>();

    final Map<GAKey, Holder> modelByGA = new ConcurrentHashMap<>();

    public static class Holder {
        private volatile boolean set;
        private volatile Model model;

        Holder() {}

        Holder(Model model) {
            this.model = Objects.requireNonNull(model);

  }

  public void testGetAndAdd() {
    Count holder = new Count(20);
    assertEquals(20, holder.get());
    holder.add(1);
    assertEquals(21, holder.get());
  }

  public void testAddAndGet() {
    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());

  }

  public void testGetAndAdd() {
    Count holder = new Count(20);
    assertEquals(20, holder.get());
    holder.add(1);
    assertEquals(21, holder.get());
  }

  public void testAddAndGet() {
    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());

    class Holder {

      int value = 2;
    }
    final Holder holder = new Holder();

    // This function adds the holder's value to the input value.
    Function<Integer, Integer> adder =
        new Function<Integer, Integer>() {
          @Override
          public Integer apply(Integer from) {
            return from + holder.value;
          }
        };

				into.addChild(h)
				// We scanned a folder, optionally send update.
				f.updateCache.deleteRecursive(h)
				f.updateCache.copyWithChildren(&f.newCache, h, folder.parent)
				f.sendUpdate()
			}
		}

		// Transfer existing
		if !into.Compacted {
			for _, folder := range existingFolders {
				h := hashPath(folder.name)
				f.updateCache.copyWithChildren(&f.oldCache, h, folder.parent)
			}

		lastHandout:  metaCacheTestsetTimestamp,
		dataVersion:  metacacheStreamVersion,
	},
	2: {
		id:           "case-3-older",
		bucket:       "bucket",
		root:         "folder/prefix",
		recursive:    false,
		status:       scanStateSuccess,
		fileNotFound: true,
		error:        "",
		started:      metaCacheTestsetTimestamp.Add(-time.Minute),
		ended:        metaCacheTestsetTimestamp,

}

func NewWalker(context *build.Context, root string) *Walker {
	w := &Walker{
		context:  context,
		root:     root,
		features: map[string]bool{},
		imported: map[string]*apiPackage{"unsafe": &apiPackage{Package: types.Unsafe}},
	}
	w.loadImports()
	return w
}

func (w *Walker) Features() (fs []string) {
	for f := range w.features {
		fs = append(fs, f)
	}