Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/html/api/cool_workers/vendor/guzzlehttp/psr7/tests/HeaderTest.php:10 Stack trace: #0 {main} thrown in /var/www/html/api/cool_workers/vendor/guzzlehttp/psr7/tests/HeaderTest.php on line 10