private void LayEdge(object sender, EdgeKeysEventArgs e)
 {
     this.edgeArgs[e.Edge] = e;
 }
 private void LayEdge(Object sender, EdgeKeysEventArgs args)
 {
     Console.Write("{0} ({1}->{2}) ",
         ((NamedEdge)args.Edge).Name,
         ((NamedVertex)args.Edge.Source).Name,
         ((NamedVertex)args.Edge.Target).Name
         );
     foreach(PointF p in args.Keys)
     {
         Console.Write(" {0}",p.ToString());
     }
     Console.WriteLine();
 }