protected function hasDnsRecordChanged($domain, $record)
    {
        if (! $dns_history = History::where('meta', $domain)->orderBy('created_at', 'desc')->first()) {
            $this->saveDnsRecord($domain, $record);
            return false;
        }

        $differences = $this->compareDnsRecords($dns_history->record, $record);

        return (count($differences['original']) && count($differences['new']));
    }