public string Charge(MoneyValue money) { money = _cantorPolicy.Exchange(money, Currency.EUR); if (_ballance.CanCharge(money)) { _ballance = new MoneyValue(_ballance.Amount - money.Amount, Currency.EUR); return($"Charge {money} success! {_currentBalance}"); } throw new InvalidOperationException($"Charge {money} can't be done on account. Rejected."); }