class Elements implements List<Element>, Cloneable {

    public Elements traverse(NodeVisitor nodeVisitor) {
        Validate.notNull(nodeVisitor);
        NodeTraversor traversor = new NodeTraversor(nodeVisitor);
        for (Element el: contents) {
            traversor.traverse(el);
        }
        return this;
    }

    public  Elements();
    public  Elements(int initialCapacity);
    public  Elements(Collection<Element> elements);
    public  Elements(List<Element> elements);
    public  Elements(Element... elements);

}