throws IOException
{
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet1 = wb.createSheet("new sheet");
sheet1.groupRow( 5, 14 );
sheet1.groupRow( 7, 10 );
sheet1.setRowGroupCollapsed( 7, true );
sheet1.setRowGroupCollapsed( 5, true );
sheet1.setRowGroupCollapsed( 8, false );
sheet1.setRowGroupCollapsed( 14, false );