1 package test;2 3 public class Test<X extends Number , Y extends RuntimeException > extends java.util.AbstractList <X> {4 5 private X singleton;6 7 public X get(int index) {8 return singleton;9 }10 11 public int size() {12 return 1;13 }14 15 public static void main(String ... args) {16 17 }18 }