* @throws XmlException
*/
private static void processTableSingleCells( XSSFSheet sheet, PackagePart singleCells, XmlObject xmlSourceObject ) throws IOException, XmlException {
SingleXmlCellsDocument singleCellsXml = SingleXmlCellsDocument.Factory.parse( singleCells.getInputStream() );
CTSingleXmlCells scs = singleCellsXml.getSingleXmlCells();
assert scs!=null;
for( CTSingleXmlCell sc : scs.getSingleXmlCellArray() ) {
final String ref = sc.getR();
assert ref!=null;
if( ref==null ) {
final String msg = String.format( "R attribute of singleCell [%] is null!", sc.getId() );