protected function setCacheFileContent($key, $content, $ttl = 0)
    {
        $result = true;
        $filepath = $this->getCacheFilePath($key);
        $content = serialize($content);
        if (file_put_contents($filepath, $content) === false) {
            $result = false;
        }

        if ($result !== false) {
            $ttl = $ttl + time();
            touch($filepath, $ttl);
        }

        return $result;
    }