private static function _createBatchHelper(Api\MtBatchSmsCreate &$batch)
    {
        $fields = [
            'from' => $batch->getSender(),
            'to' => $batch->getRecipients()
        ];

        if (null != $batch->getDeliveryReport()) {
            $fields['delivery_report'] = $batch->getDeliveryReport();
        }

        if (null != $batch->getSendAt()) {
            $fields['send_at'] = Serialize::_dateTime($batch->getSendAt());
        }

        if (null != $batch->getExpireAt()) {
            $fields['expire_at'] = Serialize::_dateTime($batch->getExpireAt());
        }

        if (null != $batch->getTags()) {
            $fields['tags'] = $batch->getTags();
        }

        if (null != $batch->getCallbackUrl()) {
            $fields['callback_url'] = $batch->getCallbackUrl();
        }

        return $fields;
    }