Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in D:\workspaces\liZiPingBack\vendor\symfony\mailer\Test\TransportFactoryTestCase.php:29 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\symfony\mailer\Test\TransportFactoryTestCase.php on line 29