Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/usonboard.com/vendor/guzzlehttp/psr7/tests/FnStreamTest.php:14 Stack trace: #0 {main} thrown in /var/www/usonboard.com/vendor/guzzlehttp/psr7/tests/FnStreamTest.php on line 14