box.setFixedDescendant(true);
    public static void positionFixedChild(Context c, Box box) {        if (LayoutUtil.isFixed(c.getCss().getCascadedStyle(box.element, false))) {//already restyled by ContentUtil            Point origin = c.getOriginOffset();            box.x = 0;            box.y = 0;            box.x -= origin.x;            box.y -= origin.y;        }    }