public function restoreDeletedContent($contentId)
    {
        $qb = $this->createQueryBuilder();
        $qb->updateMany()
            ->field('contentId')->equals($contentId)
            ->field('deleted')->set(false)
            ->getQuery()
            ->execute();
    }
public function restoreDeletedContent($contentId)
    {
        $qb = $this->createQueryBuilder();
        $qb->updateMany()
            ->field('contentId')->equals($contentId)
            ->field('deleted')->set(false)
            ->getQuery()
            ->execute();
    }
@param string $contentId

@throws \Doctrine\ODM\MongoDB\MongoDBException