void route(Edge e) {
    Node a = e.tail;
    Node b = e.head;

    double x = (a.x + b.x) /2;
    double []xroute = new double[2];
    double []yroute = new double[2];
    xroute[0] = x;
    xroute[1] = x;
    yroute[0] = a.y;
    yroute[1] = b.y;

    e.rep.route(xroute, yroute);
}