@Override
    public Spliterator<Node<T>> spliterator() {
        return Spliterators.spliterator(Collections.unmodifiableList(children),
                Spliterator.ORDERED | Spliterator.IMMUTABLE);
    }
@author Nico Bergemann <barracuda415 at yahoo.de>
@param <T>
disunity-core/src/main/java/info/ata4/util/collection/Node.java