CTWorksheet ctWorksheet = CTWorksheet.Factory.newInstance();
XSSFSheet sheet = new XSSFSheet(ctSheet, ctWorksheet, workbook);
Cell cell = sheet.createRow(0).createCell((short)0);
CTComments ctComments = CTComments.Factory.newInstance();
CommentsTable comments = new CommentsTable(ctComments);
XSSFComment comment = comments.addComment();
sheet.setCellComment("A1", comment);
assertEquals("A1", ctComments.getCommentList().getCommentArray(0).getRef());
comment.setAuthor("test A1 author");
assertEquals("test A1 author", comments.getAuthor(ctComments.getCommentList().getCommentArray(0).getAuthorId()));