public void BankAccountImposibleWithdrawal()
        {
            IBankAccount account = new BankAccountProxy("John", "Snow");
            account.Withdraw(2400);

            Assert.AreEqual(2000, account.CurrentBalance());
        }
        public void BankAccountWithdrawalTest()
        {
            IBankAccount account = new BankAccountProxy("John", "Snow");
            account.Withdraw(400);
            account.Deposit(200);

            Assert.AreEqual(1800, account.CurrentBalance());
        }