AspectJFragment {
{{
  void process() {
    CommandVisitor cV = new CommandVisitor();
    Main.cg.traverse(this, "from AspectJFragment to Compound", cV);
  }
}}
}

CommandVisitor {
{{
   void before(Compound host){
     System.out.println("This is a Compound expression:  ");
     host.print();
     System.out.println();
   }
}}
}