if (isRootLayer() && child.isAlternateFlow()) { continue; }
    private List collectLayers(int which) {        List result = new ArrayList();                if (which != AUTO) {            result.addAll(getStackingContextLayers(which));        }                List children = getChildren();        for (int i = 0; i < children.size(); i++) {            Layer child = (Layer)children.get(i);            if (! child.isStackingContext()) {                if (which == AUTO) {                    result.add(child);                }                 result.addAll(child.collectLayers(which));            }        }                return result;    }