Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\astra-backoffice\vendor\sebastian\diff\tests\Output\AbstractChunkOutputBuilderTest.php:23 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\sebastian\diff\tests\Output\AbstractChunkOutputBuilderTest.php on line 23