// generics/RestrictedComparablePets.java // ©2016 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://mindviewinc.com/Books/OnJava/ for more book information. class Hamster extends ComparablePet implements Comparable { public int compareTo(ComparablePet arg) { return 0; } } // Or just: class Gecko extends ComparablePet { public int compareTo(ComparablePet arg) { return 0; } }