Revise DerivedClassConstructionDemo to include a copy constructor for class A and class B$.$ Once done, test your code with the following main program. It should work in assigning to a$1$ a replica of a and to b$1$ a replica b$.$

public class DerivedClassConstructionDemoMain $\{$

public static void main$($String$[]$ args$)\{$

A a$,$ a$1$;

B b$,$ b$1$;

a $=$ new A$(1,2)$;

b $=$ new B$(1,2,3,4)$;

a$1=$ new A$($a$)$;

b$1=$ new B$($b$)$;

$\}$

$\}$