protected function getFindBySubjectAndSupplierQuery()
    {
        if (null !== $this->findBySubjectAndSupplierQuery) {
            return $this->findBySubjectAndSupplierQuery;
        }

        $qb = $this->createFindBySubjectQueryBuilder();

        return $this->findBySubjectAndSupplierQuery = $qb
            ->andWhere($qb->expr()->eq($this->getAlias() . '.supplier', ':supplier'))
            ->getQuery();
    }