Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\astra-backoffice\vendor\sebastian\diff\tests\Output\DiffOnlyOutputBuilderTest.php:22 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\sebastian\diff\tests\Output\DiffOnlyOutputBuilderTest.php on line 22