public void CalculateTotalInterestValue_MoreAccounts_InterestSummedFromAll()
        {
            Account[] accounts =
            {
                new Account(50)
                {
                    Amount = 1
                },                              //+0.5
                new Account(50)
                {
                    Amount = 1
                },                              //+0.5
                new Account(50)
                {
                    Amount = 1
                },                              //+0.5
            };
            decimal actualInterest = AccountClientCode.CalculateTotalInterestValue(accounts);

            Assert.AreEqual(1.5m, actualInterest);
        }
        public void CalculateTotalInterestValue_AllAccountTypes_InterestSummedFromAll()
        {
            Account[] accounts =
            {
                new SavingsAccount(50)
                {
                    Amount = 1
                },                                     //+0.5
                new CheckingAccount(50)
                {
                    Amount = 1
                },                                     //+0.5
                new AutoLoanAccount(50)
                {
                    Amount = 1
                },                                     //-0.5
            };
            decimal actualInterest = AccountClientCode.CalculateTotalInterestValue(accounts);

            Assert.AreEqual(0.5m, actualInterest);
        }