protected function getTransaction(ConsumerEvent $event)
    {
        $transactionId = $event->getMessage()->getValue('transaction_id');

        $transaction = $this->transactionManager->findOneBy([
            'id' => $transactionId,
        ]);

        if (!$transaction) {
            throw new \RuntimeException(sprintf('Unable to retrieve Transaction %d', $transactionId));
        }

        return $transaction;
    }