Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\astra-backoffice\vendor\symfony\mailer\Tests\Transport\AbstractTransportTest.php:34 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\symfony\mailer\Tests\Transport\AbstractTransportTest.php on line 34