Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\r10ca\vendor\sebastian\diff\tests\Output\Integration\StrictUnifiedDiffOutputBuilderIntegrationTest.php:42 Stack trace: #0 {main} thrown in C:\xampp\htdocs\r10ca\vendor\sebastian\diff\tests\Output\Integration\StrictUnifiedDiffOutputBuilderIntegrationTest.php on line 42