20      * @param string $eventName
25     function on($eventName, callable $callBack, $priority = 100);  argument
30      * @param string $eventName
35     function once($eventName, callable $callBack, $priority = 100);  argument
58      * @param string $eventName
63     function emit($eventName, array $arguments = [], callable $continueCallBack = null);  argument
71      * @param string $eventName
74     function listeners($eventName);  argument
82      * @param string $eventName
86     function removeListener($eventName, callable $listener);  argument
95      * @param string $eventName
98     function removeAllListeners($eventName = null);  argument