/// <summary>
 /// We use a balancing tree to locate a node smaller or equal to given key value
 /// </summary>
 public AdvancingFrontNode LocateNode(TriangulationPoint point)
 {
     return(LocateNode(point.X));
 }
 public abstract TriangulationConstraint NewConstraint(TriangulationPoint a, TriangulationPoint b);