Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in C:\xampp\htdocs\print-bk\vendor\phar-io\manifest\tests\xml\ExtensionElementTest.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\print-bk\vendor\phar-io\manifest\tests\xml\ExtensionElementTest.php on line 5