Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\soli\vendor\minishlink\web-push\tests\VAPIDTest.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\soli\vendor\minishlink\web-push\tests\VAPIDTest.php on line 18