Fatal error: Uncaught exception 'RuntimeException' with message 'PHP 5.4+ is required for this example.' in /var/www/89a.com/vendor/jeremeamia/SuperClosure/demo/factorial.php:4
Stack trace:
#0 {main}
  thrown in /var/www/89a.com/vendor/jeremeamia/SuperClosure/demo/factorial.php on line 4