WorksheetPart worksheetPart = new WorksheetPart(partName);
Relationship r = wb.addTargetPart(worksheetPart);
Sheets sheets = wb.getJaxbElement().getSheets();
Sheet s = Context.getsmlObjectFactory().createSheet();
s.setName(sheetName);
s.setId(r.getId());
s.setSheetId(sheetId);
sheets.getSheet().add(s);
// minimal content for the part
Worksheet ws = Context.getsmlObjectFactory().createWorksheet();
worksheetPart.setJaxbElement(ws);
ws.setSheetData(