Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/apache/dev/cal/web/vendor/symfony/event-dispatcher/Tests/ImmutableEventDispatcherTest.php:21 Stack trace: #0 {main} thrown in /var/www/apache/dev/cal/web/vendor/symfony/event-dispatcher/Tests/ImmutableEventDispatcherTest.php on line 21