public function getHistory()
    {
        $dqb = $this->_em->createQueryBuilder();
        $dqb->select(array('j'))
            ->from('PlaygroundCore\Entity\Cronjob', 'j')
            ->where($dqb->expr()->in('j.status', array(
                self::STATUS_SUCCESS, self::STATUS_MISSED, self::STATUS_ERROR,
            )))
            ->orderBy('j.scheduleTime', 'ASC');

        return $dqb->getQuery()->getResult();
    }