Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\demo\vendor\maennchen\zipstream-php\test\CallbackOutputTest.php:13 Stack trace: #0 {main} thrown in C:\xampp\htdocs\demo\vendor\maennchen\zipstream-php\test\CallbackOutputTest.php on line 13