如何使用java接口来计算两个集合的并、交和差，所有这些都是在接口的默认方法中完成的？

import java.util.HashSet;
import java.util.Set;

interface CollectionOperations {
    default Set<Integer> union(Set<Integer> set1, Set<Integer> set2) {
        Set<Integer> unionSet = new HashSet<>(set1);
        unionSet.addAll(set2);
        return unionSet;
    }

    default Set<Integer> intersection(Set<Integer> set1, Set<Integer> set2) {
        Set<Integer> intersectionSet = new HashSet<>(set1);
        intersectionSet.retainAll(set2);
        return intersectionSet;
    }

    default Set<Integer> difference(Set<Integer> set1, Set<Integer> set2) {
        Set<Integer> differenceSet = new HashSet<>(set1);
        differenceSet.removeAll(set2);
        return differenceSet;
    }
}

class CollectionCalculator implements CollectionOperations {
    // Implement other methods or add additional functionality if needed
}

public class Main {
    public static void main(String[] args) {
        Set<Integer> set1 = new HashSet<>();
        set1.add(1);
        set1.add(2);
        set1.add(3);

        Set<Integer> set2 = new HashSet<>();
        set2.add(3);
        set2.add(4);
        set2.add(5);

        CollectionCalculator calculator = new CollectionCalculator();

        Set<Integer> unionSet = calculator.union(set1, set2);
        System.out.println("Union: " + unionSet);

        Set<Integer> intersectionSet = calculator.intersection(set1, set2);
        System.out.println("Intersection: " + intersectionSet);

        Set<Integer> differenceSet = calculator.difference(set1, set2);
        System.out.println("Difference: " + differenceSet);
    }
}

Union: [1, 2, 3, 4, 5]
Intersection: [3]
Difference: [1, 2]