)

var (
	// isListCache maintains a cache of types that are checked for lists
	// which is used by IsListType.
	// TODO: remove and replace with an interface check
	isListCache = struct {
		lock   sync.RWMutex
		byType map[reflect.Type]bool
	}{
		byType: make(map[reflect.Type]bool, 1024),
	}
)

// IsListType returns true if the provided Object has a slice called Items.

func (p *OmitManagedFieldsPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
	if obj == nil {
		return p.Delegate.PrintObj(obj, w)
	}
	if meta.IsListType(obj) {
		obj = obj.DeepCopyObject()
		_ = meta.EachListItem(obj, func(item runtime.Object) error {
			omitManagedFields(item)
			return nil
		})
	} else if _, err := meta.Accessor(obj); err == nil {

// each accessed item, with name and age being passed to each.
func MetaToTableRow(obj runtime.Object, rowFn func(obj runtime.Object, m metav1.Object, name, age string) ([]interface{}, error)) ([]metav1.TableRow, error) {
	if meta.IsListType(obj) {
		rows := make([]metav1.TableRow, 0, 16)
		err := meta.EachListItem(obj, func(obj runtime.Object) error {
			nestedRows, err := MetaToTableRow(obj, rowFn)
			if err != nil {
				return err
			}

			Cells:  []interface{}{m.GetName(), m.GetCreationTimestamp().Time.UTC().Format(time.RFC3339)},
			Object: runtime.RawExtension{Object: obj},
		})
		return nil
	}
	switch {
	case meta.IsListType(object):
		if err := meta.EachListItem(object, fn); err != nil {
			return nil, err
		}
	default:
		if err := fn(object); err != nil {
			return nil, err
		}
	}

			return err
		}
		if info.Object == nil {
			return fn(info, nil)
		}
		if !meta.IsListType(info.Object) {
			return fn(info, nil)
		}

		items := []runtime.Object{}
		itemsToProcess := []runtime.Object{info.Object}

		for i := 0; i < len(itemsToProcess); i++ {
			currObj := itemsToProcess[i]
			if !meta.IsListType(currObj) {
				items = append(items, currObj)
				continue
			}

	if InternalObjectPreventer.IsForbidden(reflect.Indirect(reflect.ValueOf(obj)).Type().PkgPath()) {
		return fmt.Errorf(InternalObjectPrinterErr)
	}

	if meta.IsListType(obj) {
		// we allow unstructured lists for now because they always contain the GVK information.  We should chase down
		// callers and stop them from passing unflattened lists

		return
	}

	// ensure that for empty lists we don't return <nil> items.
	// This is safe to modify without deep-copying the object, as
	// List objects themselves are never cached.
	if meta.IsListType(result) && meta.LenList(result) == 0 {
		if err := meta.SetList(result, []runtime.Object{}); err != nil {
			scope.err(err, w, req)
			return
		}
	}

	var obj runtime.Object
	do := func() {

		}
	}

	if len(objects) == 1 {
		if r.singleItemImplied {
			return objects[0], nil
		}
		// if the item is a list already, don't create another list
		if meta.IsListType(objects[0]) {
			return objects[0], nil
		}
	}

	version := ""
	if len(versions) == 1 {
		version = versions.List()[0]
	}

	return toV1List(objects, version), err
}

func copyWithoutManagedFields(obj runtime.Object) (runtime.Object, bool, error) {
	isAccessor := true
	if _, err := meta.Accessor(obj); err != nil {
		isAccessor = false
	}
	isList := meta.IsListType(obj)
	_, isTable := obj.(*metav1.Table)
	if !isAccessor && !isList && !isTable {
		return nil, false, nil
	}

	// TODO a deep copy isn't really needed here, figure out how we can reliably

	tests := []struct {
		obj    runtime.Object
		isList bool
	}{
		{&testapigroup.CarpList{}, true},
		{&testapigroup.Carp{}, false},
	}
	for _, item := range tests {
		if e, a := item.isList, meta.IsListType(item.obj); e != a {
			t.Errorf("%v: Expected %v, got %v", reflect.TypeOf(item.obj), e, a)
		}
	}
}

func TestExtractList(t *testing.T) {
	list1 := []runtime.Object{