Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /opt/lampp/htdocs/us/vendor/sebastian/code-unit-reverse-lookup/tests/WizardTest.php:18 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/us/vendor/sebastian/code-unit-reverse-lookup/tests/WizardTest.php on line 18