union, intersection, difference in java (over a set)

uid.java

import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Set<Integer> s1=new HashSet<>();
		Set<Integer> s2=new HashSet<>();
		s1.addAll(Arrays.asList(new Integer[] {1,19,17,10,4,5}));
		s2.addAll(Arrays.asList(new Integer[] {10, 1, 45,17, 13, 15}));
		s1.addAll(s2);
		Set<Integer> union=new HashSet<>(s1);
		union.addAll(s2);
		System.out.println("union : ");
		System.out.println(union);
		Set<Integer> intersection=new HashSet<>(s1);
		intersection.retainAll(s2);
		System.out.println("intersection : ");
		System.out.println(intersection);
		System.out.println("difference : ");
		Set<Integer> difference=new HashSet<>(s1);
		difference.removeAll(s2);
		System.out.println(difference);
 
	}
}

intersection means common element in 2 array,
but your output is wrong ,
your intersection output is :- [1,17,10, 45, 13, 15]
correct output is:-[1,17,10]