sheet.setRowCount(4,1);
sheet.setColumnCount(4,2);
sheet.addSpan(0,0,3,3,GC.Spread.Sheets.SheetArea.colHeader);
sheet.addSpan(0,0,3,3,GC.Spread.Sheets.SheetArea.rowHeader);
sheet.addSpan(0,0,3,3,GC.Spread.Sheets.SheetArea.viewport);