doctrine-transport.php

<?php
namespace Symfony\Component\Messenger\Bridge\Doctrine\Transport;

use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
use Symfony\Component\Messenger\Transport\TransportFactoryInterface;
use Symfony\Contracts\Service\ResetInterface;

class DoctrineTransportFactory implements TransportFactoryInterface
{    
  public function createTransport(string $dsn, array $options, SerializerInterface $serializer): TransportInterface
  {
    // access to inner protected static class is allowed
    $configuration = self\PostgreSqlConnection::buildConfiguration($dsn, $options);

    if (substr($dsn, 8) === 'pgsql://') {
      $connection = new self\PostgreSqlConnection($configuration, $driverConnection);
    } else {
      $connection = new self\Connection($configuration, $driverConnection);
    }

    return new DoctrineTransport($connection, $serializer);
  }

  private class Connection implements ResetInterface {
    protected function __construct(array $configuration, DBALConnection $driverConnection, SchemaSynchronizer $schemaSynchronizer = null) {}
    protected static function buildConfiguration(string $dsn, array $options = []): array {}
  }
  
  private class PostgreSqlConnection extends self/Connection {}
}