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