Consider there object classes in Section 1.2:

Point2D, page 77, a point is identified by its coordinates (x, y)

Date, page 103, a Date is identified by (month, day, year)String, page 80, a String is identified by its string contents

Counter, page 85, a Counter is identified by its name

(a) Examine these object classes for their equals, hashCode, and compareTo, and determine if Point2D can be used for HashSet and separately if it can be used for TreeSet and then if Date can be used for its HashSet or TreeSet, and so on. Briefly explain your reasoning. Note that the same analysis holds for HashMap and TreeMap using the key object class.

(b) If the class doesnt have both an equals method and a hashCode method, write equals and/or hashCode for it based on the identifying fields listed above, so that it ends up with both methods.After this, HashSet should be usable for all four object classes.