public function createQueryBuilder($isDeleted = false)
    {
        $qb =  parent::createQueryBuilder();

        if (null !== $isDeleted) {
            $qb->addAnd(
               $qb->expr()->addOr($qb->expr()->field('isDeleted')->equals($isDeleted))
                          ->addOr($qb->expr()->field('isDeleted')->exists(false))
            );
        }

        return $qb;
    }