public void TestCase1()
{
Person testPerson = new Person()
{
FirstName = "Test", LastName = "Person1"
};
Wallet wallet = new Wallet();
testPerson.Wallets.Add(wallet);
Visa VisaCC = new Visa();
VisaCC.Balance = 100;
wallet.CreditCards.Add(VisaCC);
MasterCard MasterCC = new MasterCard();
MasterCC.Balance = 100;
wallet.CreditCards.Add(MasterCC);
Discover DiscoverCC = new Discover();
DiscoverCC.Balance = 100;
wallet.CreditCards.Add(DiscoverCC);
Assert.AreEqual(16, testPerson.TotalInterest());
Assert.AreEqual(10, VisaCC.TotalInterest());
Assert.AreEqual(5, MasterCC.TotalInterest());
Assert.AreEqual(1, DiscoverCC.TotalInterest());
}