How to do a null subclassing?

Question

I have used subclassing, but I'd like to understand it better.
Suppose I wanted to create a subclass which will not be a strict
subclass of its superclass, but it will be identical. No methods
overidden at all. The only difference would be that the original
and the clone have different name.
That would be a very good example for textbooks and tutorials.
How would one create such a class?
TIA,
-Ramon

Answer 1

it's the so called default constructor for extended classes and it's supplied automatically.It's supplied automatically only if there is no user-defined constructor. So if you define one taking an int, you have to definer the no-arg one explicitly.
public class B {
private B (int i) {}
$ javac B.java
$ javap B
Compiled from B.java
public synchronized class B extends java.lang.Object
    /* ACC_SUPER bit set */
$ javap -private B
Compiled from B.java
public synchronized class B extends java.lang.Object
    /* ACC_SUPER bit set */
    private B(int);
}