(in Java) Using a USet, implement a Bag. A Bag is like a USetit supports the add(x), remove(x), and find(x) methodsbut it allows duplicate elements to be stored. The find(x) operation in a Bag returns some element (if any) that is equal to x. In addition, a Bag supports the findAll(x) operation that returns a list of all elements in the Bag that are equal to x.