Jasper Report CSV

I am new to jasper reports.

I created a new jasper report which has a group header section and a detail section. The output format for this report is CSV. When my group header and detail section has the same number of fields everything works fine. However, if I have more number of fields in my group header, my detail row is padded with the extra commas at the end. Is this expected behavior? Can I have a work around for this?

For example: If I have 4 fields in my group header section and 2 fields in my detail section.

Current behavior: summaryField1, summaryField2, summaryField3, summaryField4 detailField1, detailField2,,

Desired behavior summaryField1, summaryField2, summaryField3, summaryField4 detailField1, detailField2

Thanks