public Integer getTotalExpense() {
   Integer result = 0;
   if (cacKhoanChi != null) {
     for (GiaoDich gd : cacKhoanChi) {
       result += gd.getSoTien();
     }
   }
   return result;
 }
 public Integer getTotalLoan() {
   Integer result = 0;
   if (cacKhoanChoVay != null) {
     for (GiaoDich gd : cacKhoanChoVay) {
       result += gd.getSoTien();
     }
   }
   return result;
 }
 public Integer getTotalIncome() {
   Integer result = 0;
   if (cacKhoanThu != null) {
     for (GiaoDich gd : cacKhoanThu) {
       result += gd.getSoTien();
     }
   }
   return result;
 }