Write a CashRegister class that can be used with the Retailltem class that you wrote in Chapter 6's Programming Challenge 4. The CashRegister class should simulate the sale of a retail item. It should have a constructor that accepts a Retail Item object as an argument. The constructor should also accept an integer that represents the quantity of items being purchased. In addition, the class should have the following methods:
Demonstrate the class in a program that asks the user for the quantity of items being purchased, and then displays the sale's subtotal, amount of sales tax, and total.