class InterfaceExample implements Displayer
      { 
      public void display ()
        {
        System.out.println ("An instance of InterfaceExample");
        }

      public static void main (String args[])
        {
        Displayer d;

        d = new InterfaceExample ();
        d.display ();
        d = new MyClass ();
        d.display ();
        } 
      } 

    class MyClass implements Displayer
      {
      public void display ()
        {
        System.out.println ("An instance of MyClass");
        }
      }

    interface Displayer
      {
      public void display ();
      }