Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/crm_killing_ninja/vendor/ezimuel/guzzlestreams/tests/AppendStreamTest.php:9 Stack trace: #0 {main} thrown in /var/www/crm_killing_ninja/vendor/ezimuel/guzzlestreams/tests/AppendStreamTest.php on line 9