Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in E:\xampp\htdocs\stms\vendor\laravel\framework\src\Illuminate\Foundation\Testing\TestCase.php:18 Stack trace: #0 {main} thrown in E:\xampp\htdocs\stms\vendor\laravel\framework\src\Illuminate\Foundation\Testing\TestCase.php on line 18