@Override
 public String getKeyColumn() {
   return b.getId() + "";
 }
 @Override
 public int compareTo(BoardingGateView o) {
   return (b.getId() + "").compareTo(o.getId());
 }
 public String getId() {
   if (b != null) return b.getId() + "";
   return "";
 }
 @Override
 public String getSelectCode() {
   return b.getId() + "";
 }