private void AddEdges(IEnumerable newItems) { if (newItems == null) { return; } foreach (IEdge edge in newItems) { if (edge != null) { _algorithm.AddEdge(edge); var item = new Line { DataContext = edge, StrokeThickness = 1, Stroke = Brushes.Black }; SetZIndex(item, EdgeZIndex); _edgesToItems.Add(edge, item); Children.Add(item); } } }