CellReference cellRefTo = new CellReference(cra.getLastRow(), cra.getLastColumn(),true,true);
sb.append(cellRefFrom.formatAsString());
//for a single-cell reference return A1 instead of A1:A1
if(!cellRefFrom.equals(cellRefTo)){
sb.append(':');
sb.append(cellRefTo.formatAsString());
}
return sb.toString();
}
//20110512, peterkuo@potix.com