private function containsFiles($key, $regionName, &$policy = null, &$cache = null) {
        $this->getCacheFilePaths($key, $regionName, $policy, $cache);

        if (!is_file($policy) && !is_file($cache)) {
            return false;
        }
        elseif (!is_file($policy) && is_file($cache)) {
            $this->tryDeleteFile($cache);
        }
        elseif (is_file($policy) && !is_file($cache)) {
            $this->tryDeleteFile($policy);
        }

        return true;
    }