class Point2dDifference extends AbstractDifferenceList implements IDifferenceList {

    public static IDifference construct(String name, Point2d first, Point2d second) {
        if (first == null && second == null) return null;

        Point2dDifference totalDiff = new Point2dDifference(name);
        totalDiff.addChild(DoubleDifference.construct("x", first == null ? null : first.x, second == null ? null
                : second.x));
        totalDiff.addChild(DoubleDifference.construct("y", first == null ? null : first.y, second == null ? null
                : second.y));
        if (totalDiff.childCount() == 0) {
            return null;
        }
        return totalDiff;
    }

    private  Point2dDifference(String name);

}