ArrayList containsAll(Collection c) method in java

import java.util.ArrayList;
public class ArrayListContainsAllMethodExample
{
   public static void main(String[] args)
   {
      ArrayList<String> al1 = new ArrayList<String>();
      al1.add("red");
      al1.add("green");
      al1.add("blue");
      System.out.println("ArrayList 1: " + al1);
      // creating another ArrayList
      ArrayList<String> al2 = new ArrayList<String>();
      // adding elements to second ArrayList
      al2.add("blue");
      al2.add("green");
      System.out.println("ArrayList 2: " + al2);
      // checking if ArrayList 1 contains ArrayList 2
      boolean output1 = al1.containsAll(al2);
      System.out.println("Does ArrayList 1 contains all elements of ArrayList 2?: " + output1);
      // checking if ArrayList 2 contains ArrayList 1
      boolean output2 = al2.containsAll(al1);
      System.out.println("Does ArrayList 2 contains all elements of ArrayList 1?: " + output2);
   }
}