@Override
    public boolean remove(Object o) {
        boolean removed = children.remove(o);
        if (removed) {
            ((Node<T>) o).parent(null);
        }
        return removed;
    }
@author Nico Bergemann <barracuda415 at yahoo.de>
@param <T>
disunity-core/src/main/java/info/ata4/util/collection/Node.java