Fatal error: Uncaught Error: Class "Symfony\Component\Mailer\Test\AbstractTransportFactoryTestCase" not found in /media/jean/learning/huagai/drupal/vendor/symfony/mailer/Test/TransportFactoryTestCase.php:29 Stack trace: #0 {main} thrown in /media/jean/learning/huagai/drupal/vendor/symfony/mailer/Test/TransportFactoryTestCase.php on line 29