ROBOT export generates error in large excel exports

[dlutz2]

When trying to export an ontology with more than 64,000 classes into an Excel file, ROBOT (v1.9.4) export generated an error "The maximum number of Cell Styles was exceeded. You can define up to 64000 style in a .xlsx Workbook", which I believe is coming from the POI library. I think it is caused by the the CellStyle style = wb.createCellStyle(); call in robot.export.Row.addToWorkbook() which creates a new CellStyle for each row. The export works fine when exporting to text and html.

[jamesaoverton]

Yes, it looks like we could reuse a small number of CellStyles instead of creating one for each cell. I would be happy to accept a PR for that.

[dlutz2]

Unfortunately, the team is not yet set up for public github forks/PRs. We actually have a couple of simple additions to ROBOT we've developed in house for our own purposes e.g. we want to be able to export-edit-template lossless round trips. We would like to generate PRs for those when we get out act together.
thanks