public function broadcast(Message $message, string $topicArn)
    {
        if ($this->debug) {
            $this->logger && $this->logger->notice(
                "Message would have been sent to $topicArn",
                [
                    'Message' => $message,
                ]
            );

            return;
        }

        $this->messages->send($message, $topicArn);
    }