private function shiftRlValues(AbstractNestedNode $node, $first, $delta)
    {
        $this->createQueryBuilder('n')
            ->set('n._leftnode', 'n._leftnode + :delta')
            ->andRootIs($node->getRoot())
            ->andLeftnodeIsUpperThan($first)
            ->setParameter('delta', $delta)
            ->update()
            ->getQuery()
            ->execute()
        ;

        $this->createQueryBuilder('n')
            ->set('n._rightnode', 'n._rightnode + :delta')
            ->andRootIs($node->getRoot())
            ->andRightnodeIsUpperThan($first)
            ->setParameter('delta', $delta)
            ->update()
            ->getQuery()
            ->execute()
        ;

        return $this;
    }