import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
        equals(null, null);
        equals(null, false);
        equals(null, true);
        equals(false, null);
        equals(false, false);
        equals(false, true);
        equals(true, null);
        equals(true, false);
        equals(true, true);

        equals2(null, null);
        equals2(null, "red");
        equals2(null, "blue");
        equals2("red", null);
        equals2("red", "red");
        equals2("red", "blue");
        equals2("blue", null);
        equals2("blue", "red");
        equals2("blue", "blue");
    }


    private static void equals(Boolean b1, Boolean b2) {
        System.out.println("---");
        System.out.println("b1: '" + b1 + "', b2: '" + b2 + "'");
        System.out.println("b1 == b2: '" + (b1 == b2) + "'");
        System.out.println("Objects.equals(b1, b2): '" + Objects.equals(b1, b2) + "'");
    }


    private static void equals2(String s1, String s2) {
        System.out.println("===");
        System.out.println("s1: '" + s1 + "', s2: '" + s2 + "'");
        System.out.println("s1 == s2: '" + (s1 == s2) + "'");
        System.out.println("Objects.equals(s1, s2): '" + Objects.equals(s1, s2) + "'");
    }
}