CapgeminiSurface.FavouriteStack.AddInstancePropertyObject C# (CSharp) Метод

        public void AddInstancePropertyObject(object sender)
        {
            var item = sender as ContentItem;
            if (item != null)
            {

                var stackSource = _collection.Source as List<ContentItem>;
                if (stackSource != null)
                {
                    stackSource.Add(item);
                    _collection.Source = stackSource;
                    _collection.GroupDescriptions.Add(new PropertyGroupDescription("ContentType"));
                    favouriteStackContent.ItemsSource = null;
                    favouriteStackContent.ItemsSource = _collection.View;
                }
            }
        }