public void Withdraw(BankUser bankUser, decimal money,decimal bankWithdrawFeeRate)
 {
     bankUser.Balance -= (money+money*bankWithdrawFeeRate);
     bankUser.LastTransactionTime = DateTime.Now;
 }
 public void Deposit(BankUser bankUser, decimal money)
 {
     bankUser.Balance = money;
     bankUser.LastTransactionTime = DateTime.Now;
 }