public void AddAfter(T anchor, T item)
{
if (anchor == null)
{
throw new ArgumentNullException(nameof(anchor));
}
if (!_nodes.Contains(anchor))
{
throw new InvalidOperationException("Anchor item not found in list");
}
var anchorNode = _nodes[anchor].First();
var node = _tree.AddAfter(anchorNode, item);
_nodes.Add(item, node);
}
IEnumerable <object> _calcSelectedItemsFromSelectedValues()
{
if (_selectedValues == null)
{
yield break;
}
foreach (var key in _selectedValues.Cast <object>().Distinct())
{
if (_keyToItems.Contains(key))
{
foreach (var item in _keyToItems[key])
{
yield return(item);
}
}
}
}