private function getOrderingDescendants($depth = null, $order = [])
    {
        if (1 === $depth && true === empty($order)) {
            $order = [
                '_position' => 'ASC',
                '_leftnode' => 'ASC',
            ];
        } elseif (true === empty($order)) {
            $order = [
                '_leftnode' => 'ASC',
                '_level' => 'ASC',
                '_position' => 'ASC',
            ];
        }

        return $order;
    }