Given the following code, how should the toString methods in the classes H2ClassA and H2ClassB be written to give the indicated output and take advantage of the natural toString method in H2ClassB?

1 import java.util.ArrayList;

2

3 public class H2ClassA {

4 ArrayList list = new ArrayList ();

5

6 public static void main (String args []) {

7 H2ClassA y = new H2ClassA ();

8 int [] v = {4, 3, 7, 5, 99, 3};

9 for (int m: v)

10 y.list.add (new H2ClassB (m));

11 System.out.println (y);

12 } // end main

13

14 } // end class H2ClassA

15

16 class H2ClassB {

17 int x;

18 H2ClassB (int a) { x = a;}

19 } // end H2ClassB

OUTPUT: 4 3 7 5 99 3