public function siblingMenu()
    {
        $nb = $this->spawn('siblingMenu', new Collection());

        $parent = $this->active()->parent();
        if ($parent) {
            $siblings = $parent->children();
        } else {
            $siblings = $this->roots();
        }

        if ($siblings->count() > 1) {
            foreach ($siblings as $s) {
                $nb->add($s->title, $s->url());
            }
        }

        return $nb;
    }