public override void OnApplyTemplate()
{
base.OnApplyTemplate();
Surface = (GetTemplateChild("PART_ContentHostNodes") as ItemsControl);
Surface2 = (GetTemplateChild("PART_ContentHostLines") as ItemsControl);
CalculateGenerations();
Surface.Width = Generations.Max(n => n.Nodes.Count) * HorizontalNodeSpace;
Surface.Height = Generations.Count * VerticalNodeSpace;
Surface2.Width = Surface.Width;
Surface2.Height = Surface.Height;
AllocateNodes(Nodes);
AllocateLines();
}