docs: public static void defineDefaultConstructor(ClassVisitor cv, TypeInfo ownerType) {
      CodeBuilder mg = new CodeBuilder(Opcodes.ACC_PUBLIC, NULLARY_INIT, null, cv);
      mg.visitCode();
      Label start = mg.mark();
      Label end = mg.newLabel();
      LocalVariable thisVar = LocalVariable.createThisVar(ownerType, start, end);
      thisVar.gen(mg);
      mg.invokeConstructor(OBJECT.type(), NULLARY_INIT);
      mg.returnValue();
      mg.mark(end);
      thisVar.tableEntry(mg);
      mg.endMethod();
    }