public function attach($name, \Closure $callback, $priority = 0)
    {
        $key = $this->storeCallback($callback);

        if (is_array($name)) {
            foreach ($name as $event) {
                $this->pushToQueue($event, $key, $priority);
            }
        } else {
            $this->pushToQueue($name, $key, $priority);
        }

        return $this;
    }