Row r2s2 = sheet2.createRow(2);
Cell c1r2s2 = r2s2.createCell(1);
assertNull(c1r2s2.getCellComment());
Comment cc2 = sheet2.createComment();
cc2.setAuthor("Also POI");
cc2.setString(new XSSFRichTextString("A new comment"));
c1r2s2.setCellComment(cc2);