internal void RemoveRange(int startIndex, int endIndex)
        {
            for (int i = startIndex; i <= endIndex; i++)
            {
                if (i > _items.Count)
                {
                    break;
                }

                StaggeredItem item = _items[i];
                item.Height = 0;
                item.Top    = 0;

                // We must recycle all elements to ensure that it gets the correct context
                RecycleElementAt(i);
            }

            foreach (var kvp in _columnLayout)
            {
                StaggeredColumnLayout layout = kvp.Value;
                for (int i = 0; i < layout.Count; i++)
                {
                    if ((startIndex <= layout[i].Index) && (layout[i].Index <= endIndex))
                    {
                        int numToRemove = layout.Count - i;
                        layout.RemoveRange(i, numToRemove);
                        break;
                    }
                }
            }
        }
        internal void RemoveFromIndex(int index)
        {
            if (index >= _items.Count)
            {
                // Item was added/removed but we haven't realized that far yet
                return;
            }

            int numToRemove = _items.Count - index;

            _items.RemoveRange(index, numToRemove);

            foreach (var kvp in _columnLayout)
            {
                StaggeredColumnLayout layout = kvp.Value;
                for (int i = 0; i < layout.Count; i++)
                {
                    if (layout[i].Index >= index)
                    {
                        numToRemove = layout.Count - i;
                        layout.RemoveRange(i, numToRemove);
                        break;
                    }
                }
            }
        }