Challenge: Facade Pattern

Problem statement

In this challenge, you have to implement a part of an online hair product ordering system. The available products are shampoo, conditioner, and hair serum. A customer who is shopping online can buy any of these. A product object has the following properties:

• productName: name of the product, that is, shampoo, conditioner, or hair serum

• amount: the number of bottles that the customer ...