public function status($numerator, $denominator)
    {
        if (!count($this->callback[self::TASK_STATUS])) {
            return;
        }

        foreach ($this->callback[self::TASK_STATUS] as $callback) {
            call_user_func($callback,
                           $this->func,
                           $this->handle,
                           $numerator,
                           $denominator);
        }
    }