Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\astra-backoffice\vendor\laravel\framework\tests\Foundation\Testing\TestCaseTest.php:15 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\laravel\framework\tests\Foundation\Testing\TestCaseTest.php on line 15