public function findByProcessingId($processingId)
    {
        $handlers = [];

        $builder = $this->connection->createQueryBuilder();

        $builder->select('*')->from(Tables::MESSAGE_HANDLER)
            ->where($builder->expr()->eq('processing_id', ':processing_id'))
            ->setParameter('processing_id', $processingId);

        foreach($builder->execute() as $row) {
            $this->fromDatabase($row);
            array_push($handlers, $row);
        }

        return $handlers;
    }