public class Mediator {
  public void lock() {
    System.out.println("Locking turnstile.");
  }
  public void unlock() {
    System.out.println("Unlocking turnstile");
  }
  public void alarm() {
    System.out.println("Sounding alarm");
  }
  public void thankyou() {
    System.out.println("Thank you, very much!");
  }
}