Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/u932159897/domains/devapps.website/public_html/api/vendor/slim/psr7/tests/HeaderTest.php:16 Stack trace: #0 {main} thrown in /home/u932159897/domains/devapps.website/public_html/api/vendor/slim/psr7/tests/HeaderTest.php on line 16