import EDU.neu.ccs.demeter.dj.Visitor;

public class MyVisitor extends Visitor {
  public void start() { System.out.println("start"); }
  public void finish() { System.out.println("finish"); }

  public void before(A o) { System.out.println("before A"); }
  public void after(A o)  { System.out.println("after A"); }

  public void before(B o) { System.out.println("before B"); }
  public void after(B o)  { System.out.println("after B"); }

  public void before(X o) { System.out.println("before X"); }
  public void after(X o)  { System.out.println("after X"); }

  public void before(Y o) { System.out.println("before Y"); }
  public void after(Y o)  { System.out.println("after Y"); }
}