Part B: Strategy Pattern We've already seen a design pattern, the iterator pattern, that allowed us to iterate over any collection of items without knowing how the collection is actually implemented. In this part of the lab, we'll be looking at another design pattern called the Strategy Pattern. It involves applying a collection of methods (with an interface in common) to a list of objects. Create an interface like this: public interface OpClass { abstract Object op (Object arg); Next, create three classes Square, Cube, and SquareRoot that implement this interface. The Square should convert the arg to a Number, square it, then return the Number as an object. The Cube will do the same thing, expect it will cube the number. The same applies to the SquareRoot which returns the square root of the number. Create a method called apply in another public class called Calculator and implement your main method here. The apply method should accept an ArrayList of Numbers and an OpClass to apply to the list. It should return a new ArrayList with the new values in it. Make use of the ArrayList iterator here as well. Test this out by building a list of integers, and applying the square, cube, then square root objects on the list. Print out the list after each application.