(E-commerce) When shopping online, you select items and add them to a shopping cart. Duplicate items are permitted in a shopping cart, as you can purchase multiples of the same item. You also can remove an item from a shopping cart, if you change your mind about buying it. The shopping cart can show its current contents with their prices and the total cost of these items.

1. Design the ADTs item and shopping cart. Specify each ADT operation by stating its purpose, by describing its parameters, and by writing a pseudocode version of its header. Then write, a Java interface for an item's methods and one for the methods of a shopping cart. Include javadoc -style comments in your code.

2. Draw a UML class diagram for MyShop class that implements one of the interfaces.

3. Write, an implementation class for the UML class diagram you draw for b. Use "MyShop" class name.