import java.util.HashSet;

public class HashSetDemo15m {
    public static void main(String[] args) {

        HashSet set1 = new HashSet();
        HashSet set2 = new HashSet();
        set1.add(1);
        set1.add(2);
        set1.add(3);
        set1.add(4);

        set2.add("A");
        set2.add("a");
        set2.add("B");
        set2.add("b");
        set2.add("C");
        set2.add("c");

        set1.stream().filter( e -> (e ==1)).forEach(System.out::println);
        set2.stream().filter( e -> (e == "A")).forEach(System.out::println);
        

    }

}