public static Edge_Edge CreateEdge(LGSPGraph graph, LGSPNode source, LGSPNode target)
        {
            Edge_Edge edge = new Edge_Edge(source, target);

            graph.AddEdge(edge);
            return(edge);
        }
		public static Edge_Edge CreateEdge(LGSPGraph graph, LGSPNode source, LGSPNode target)
		{
			Edge_Edge edge = new Edge_Edge(source, target);
			graph.AddEdge(edge);
			return edge;
		}