Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\r10csm\vendor\laravel\framework\tests\Integration\Database\EloquentModelCustomCastingTest.php:20 Stack trace: #0 {main} thrown in C:\xampp\htdocs\r10csm\vendor\laravel\framework\tests\Integration\Database\EloquentModelCustomCastingTest.php on line 20