@Override
    protected List<Row> convertRows(InLongMsgHead head, InLongMsgBody body) throws Exception {
        Row dataRow =
                InLongMsgTlogCsvUtils.deserializeRow(
                        rowFormatInfo,
                        nullLiteral,
                        head.getPredefinedFields(),
                        body.getFields());

        Row row = InLongMsgUtils.decorateRowWithNeededHeadFields(
                timeFieldName,
                attributesFieldName,
                head.getTime(),
                head.getAttributes(),
                dataRow);
        return Collections.singletonList(row);
    }
The literal represented null values, default "".
inlong-sort/sort-formats/format-row/format-inlongmsg-tlogcsv/src/main/java/org/apache/inlong/sort/formats/inlongmsgtlogcsv/InLongMsgTlogCsvFormatDeserializer.java