for (POIXMLDocumentPart p : wb.getRelations()) {
if (!(p instanceof MapInfo)) {
continue;
}
MapInfo mapInfo = (MapInfo) p;
XSSFMap map = mapInfo.getXSSFMapById(4);
assertNotNull("XSSFMap is null", map);
XSSFExportToXml exporter = new XSSFExportToXml(map);
ByteArrayOutputStream os = new ByteArrayOutputStream();