System.Windows.Controls.SelectionMultiple.SelectParentFromKey C# (CSharp) Method

        public bool SelectParentFromKey()
        {
            DependencyObject parent = GetFocusedItem();
            while (parent != null)
            {
                parent = VisualTreeHelper.GetParent(parent);
                if (parent is MultiSelectTreeViewItem) break;
            }
            return SelectFromKey(parent as MultiSelectTreeViewItem);
        }