Extend bag ADT by a. Add the methods union, intersection, and difference to the bag ADT. The union of two bags is a new bag containing the combined contents of the original two bags. The intersection of two bags is a new bag containing the entries that occur in both of the original two bags. The difference of two bags is a new bag containing the entries that would be left in one bag after removing those that also occur in the second. b. Implement union method for class LinkedBag. c. Implement intersect method for class LinkedBag d. Imlplement difference method for class LinkedBag