public void TestMultiplication()
{
Dollar five = new Dollar(5);
Dollar product = five.times(2);
Assert.AreEqual(10, product.amount);
Dollar product2 = five.times(3);
Assert.AreEqual(15, product2.amount);
}
public override bool Equals(object obj)
{
Dollar dollar = (Dollar)obj;
return(_amount == dollar._amount);
}