Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in D:\xampp\htdocs\jconf\ck\vendor\symfony\service-contracts\Test\ServiceLocatorTestCase.php:18 Stack trace: #0 {main} thrown in D:\xampp\htdocs\jconf\ck\vendor\symfony\service-contracts\Test\ServiceLocatorTestCase.php on line 18