Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /Applications/XAMPP/xamppfiles/htdocs/Project_April/selling-partner-api-main/test/AuthenticationTest.php:15 Stack trace: #0 {main} thrown in /Applications/XAMPP/xamppfiles/htdocs/Project_April/selling-partner-api-main/test/AuthenticationTest.php on line 15