vendor/symfony/mailer/EventListener/MessengerTransportListener.php line 26
<?php/** This file is part of the Symfony package.** (c) Fabien Potencier <fabien@symfony.com>** For the full copyright and license information, please view the LICENSE* file that was distributed with this source code.*/namespace Symfony\Component\Mailer\EventListener;use Symfony\Component\EventDispatcher\EventSubscriberInterface;use Symfony\Component\Mailer\Event\MessageEvent;use Symfony\Component\Messenger\Stamp\TransportNamesStamp;use Symfony\Component\Mime\Message;/*** Allows messages to be sent to specific Messenger transports via the "X-Bus-Transport" MIME header.** @author Fabien Potencier <fabien@symfony.com>*/final class MessengerTransportListener implements EventSubscriberInterface{public function onMessage(MessageEvent $event): void{if (!$event->isQueued()) {return;}$message = $event->getMessage();if (!$message instanceof Message || !$message->getHeaders()->has('X-Bus-Transport')) {return;}$names = $message->getHeaders()->get('X-Bus-Transport')->getBody();$names = array_map('trim', explode(',', $names));$event->addStamp(new TransportNamesStamp($names));$message->getHeaders()->remove('X-Bus-Transport');}public static function getSubscribedEvents(): array{return [MessageEvent::class => 'onMessage',];}}