public void add(Element element) {
        System.out.println("element added");
        elements.add(element);
        fireElementAdded(element);
        if (element instanceof Obstacle) {
            System.out.println("obstacle added");
            obstacles.add((Obstacle) element);
            fireObstacleAdded((Obstacle) element);
        }
        if (element instanceof AccessPoint) {
            System.out.println("ap added");
            aps.add((AccessPoint) element);
            fireAccessPointAdded((AccessPoint) element);
        }
    }