private protected override void UpdateInterfaceType(Type nodeType) { base.UpdateInterfaceType(nodeType); Debug.Assert(InterfaceType != null); Type EstimatedItemType = NodeTreeHelper.InterfaceTypeToNodeType(InterfaceType); Debug.Assert(EstimatedItemType != null); if (ItemType == null) { InsertType = EstimatedItemType; } else { InsertType = ItemType; } }