public function complete($result)
    {
        $this->finished = true;
        $this->result = $result;

        if (!count($this->callback[self::TASK_COMPLETE])) {
            return;
        }

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