Example of the Bag implementation behavior

BagMain.java

package ;

import java.util.Collection;

public class BagMain {

    public static void main(String[] args) {
        Collection<Integer> bag = new Bag<Integer>();
        bag.add(1);
        bag.add(5);
        bag.add(7);
        bag.add(8);
        bag.add(1);
        bag.add(12);
        bag.add(1);
        for (Integer i : bag) {
            System.out.print(i + ",");
        }
        // output: 1,1,1,5,7,8,12,
        System.out.println();
        for (Integer i : bag) {
            System.out.print(i + ",");
        }
        // output: 1,1,1,5,7,8,12,
}

LinkedBag.java

package ;

import java.util.Collection;

public class LinkedBag {

    public static void main(String[] args) {
        Collection<Integer> bag = new LinkedBag<Integer>();
        bag.add(1);
        bag.add(5);
        bag.add(7);
        bag.add(8);
        bag.add(1);
        bag.add(12);
        bag.add(1);
        for (Integer i : bag) {
            System.out.print(i + ",");
        }
        // output: 1,5,7,8,1,12,1,
        System.out.println();
        for (Integer i : bag) {
            System.out.print(i + ",");
        }
        // output: 1,5,7,8,1,12,1,
}