public function retrieveByPartialHeadline($query)
    {
        $query = $this->createQueryBuilder('q')
            ->select('q.id, q.headline')
            ->where('q.headline LIKE :query')
            ->orderBy('q.publishAt', 'DESC')
            ->setParameter('query','%'.$query.'%')
            ->getQuery();

        return $query->getArrayResult();
    }