Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\r10ca\vendor\symfony\mailer\Tests\Exception\UnsupportedSchemeExceptionTest.php:33 Stack trace: #0 {main} thrown in C:\xampp\htdocs\r10ca\vendor\symfony\mailer\Tests\Exception\UnsupportedSchemeExceptionTest.php on line 33