public function remove($key, $regionName = null) {
        if ($this->containsFiles($key, $regionName, $policy, $cache)) {
            if ($this->getCacheContent($policy, $cache, $result) === true) {
                $this->tryDeleteFile($policy);
                $this->tryDeleteFile($cache);
            }

            return $result;
        }
        else {
            return null;
        }
    }