protected internal virtual Dijkstra <double> GetDijkstra(SimpleGraphBuilder graph, double?startCost, string startNode, string endNode)
 {
     return(new Dijkstra <double>(startCost, graph.GetNode(startNode), graph.GetNode(endNode), CommonEvaluators.doubleCostEvaluator("cost"), new DoubleAdder(), double?.compareTo, Direction.BOTH, MyRelTypes.R1));
 }