Implement a public class called comparepets. comparepets should provide a single static method named equals that takes two pet references and returns an int. if the two pet references are equal you should return 1. else if the two pet instances are equal you should return -1. otherwise return 0. note that one or both of the pet references may be null, in which case you should return 0 unless both are null in which case you should return 1. java