Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in D:\programs\xampp\htdocs\backend-test\vendor\webklex\php-imap\tests\ClientTest.php:31 Stack trace: #0 {main} thrown in D:\programs\xampp\htdocs\backend-test\vendor\webklex\php-imap\tests\ClientTest.php on line 31