Based on the equals method for Circle objects defined in Section 6.1, what is the output of the following code sequence?

Circle c1 = new Circle(5);

Circle c2 = new Circle(5);

Circle c3 = new Cirle(15);

Circle c4 = null;

System.out.println(c1 == c1);

System.out.println(c1 == c2);

System.out.println(c1 == c3);

System.out.println(c1 == c4);

System.out.println(c1.equals(c1));

System.out.println(c1.equals(c2));

System.out.println(c1.equals(c3));

System.out.println(c1.equals(c4));