void HandleEdgeUpdate(EpForceDirectedGraph.cs.Edge edge, Spring spring)
    {
        var from = PositionToVector3(spring.point1.position);
        var to   = PositionToVector3(spring.point2.position);

        Debug.DrawLine(from, to, Color.white, Time.deltaTime);
    }
 protected abstract void drawEdge(Edge iEdge, AbstractVector iPosition1, AbstractVector iPosition2);