public function findSecurityTypeById($id)
    {
        try {
            $qb = $this->createQueryBuilder('securityType')
                ->where('securityType.id=:securityTypeId');

            $query = $qb->getQuery();
            $query->setParameter('securityTypeId', $id);

            return $query->getSingleResult();
        } catch (NoResultException $ex) {
            return;
        }
    }