Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in E:\xampp\htdocs\webhost_v2\vendor\symfony\service-contracts\Test\ServiceLocatorTest.php:18 Stack trace: #0 {main} thrown in E:\xampp\htdocs\webhost_v2\vendor\symfony\service-contracts\Test\ServiceLocatorTest.php on line 18