Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/noct-c/www/mitanitouki_admin/vendor/sebastian/environment/tests/OperatingSystemTest.php:17 Stack trace: #0 {main} thrown in /home/noct-c/www/mitanitouki_admin/vendor/sebastian/environment/tests/OperatingSystemTest.php on line 17