public void ATMCardSuccessfulTransactionTest()
        {
            var client = new NaturalPerson("Jan Kowalski", "11312737254");
            var card   = new ATMCard("1234567890", client, true, 1250.12m);

            card.MakeTransaction(1200m);
            Assert.AreEqual(card.Balance, 2450.12m);
        }
        public void ATMCardTransactionRejectedTest()
        {
            var client = new NaturalPerson("Jan Kowalski", "11312737254");
            var card   = new ATMCard("1234567890", client, true, 1250.12m);

            try
            {
                card.MakeTransaction(-1500m);
            }
            catch (InsufficientCardBalanceException)
            {
                Assert.AreEqual(card.Balance, 1250.12m);
            }
            Assert.AreEqual(card.Balance, 1250.12m);
        }