private static void AddItemsTo(BindableCollection <Node> newParentCollection, IFlatListItem insertPlace, IEnumerable <Node> items)
{
var newItems = new List <Node>();
var position = newParentCollection.IndexOf(insertPlace as Node);
if (position != -1)
{
newItems.AddRange(newParentCollection.Take(position));
newItems.AddRange(items);
newItems.AddRange(newParentCollection.Skip(position));
}
else
{
newItems.AddRange(newParentCollection);
newItems.AddRange(items);
}
newParentCollection.IsNotifying = false;
newParentCollection.Clear();
newParentCollection.AddRange(newItems);
newParentCollection.IsNotifying = true;
newParentCollection.Refresh();
}