Unexpected change of CtConstructor parameter type

[juda]

I've noticed strange CtConstructor's constructor behavior. The following code illustrates the problem:

import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;

public class Test {
 Test( Test t ){}

 public static void main(String[] args) throws Exception {
 ClassPool pool = ClassPool.getDefault();

 CtClass baseCtClass = pool.getCtClass( Test.class.getName() );
 CtClass childCtClass = pool.makeClass( Test.class.getName() + "$$Ex", baseCtClass );

 assert baseCtClass.getDeclaredConstructors().length == 1;
 assert baseCtClass.getDeclaredConstructors()[0].getParameterTypes().length == 1;
 assert baseCtClass.getDeclaredConstructors()[0].getParameterTypes()[0].equals( baseCtClass );

 assert childCtClass.getDeclaredConstructors().length == 0;

 CtConstructor childCtor = new CtConstructor( baseCtClass.getDeclaredConstructors()[0], childCtClass, null );
 childCtor.setBody( "{ super($$); }" );
 childCtClass.addConstructor( childCtor );

 assert childCtClass.getDeclaredConstructors().length == 1;
 assert childCtClass.getDeclaredConstructors()[0].getParameterTypes().length == 1;
 assert childCtClass.getDeclaredConstructors()[0].getParameterTypes()[0].equals( baseCtClass );
 //the last assert fails (at least using Sun's jdk 1.6 u 10 / javassist 3.9.0 )
 //for some reason ctor parameter type is Test$$Ex instead of Test
 }
}

Last program assertion fails. The CtConstructor parameter is changed from Test to the Test$$Ex. Is it done on purpose?

Regards