Code Injection in Custom Methods

// This illustrates separate code injection
// for custom and generated methods
// The output will be as follows
// Sound of beep
// Warning
//  ... this is injected after the warning
// Sound of beep
// Warning
//  ... this is injected after the warning
// Sound of beep
// Warning
// ... this is injected after the warning
//
class Car {
  queued radio {
    on {
      radioToggle -> off;
    }
    off {
      radioToggle -> on;
    }
  }
  after generated radioToggle* {soundBeep();}
  
  void soundBeep() {
    System.out.println("Sound of beep");
    radioToggleWarning();
  }

  void radioToggleWarning() {
    System.out.println("Warning");
  }
  
  after custom radioToggle* {
    System.out.println(
      " ... this is injected after the warning");  
  }
  
  public static void main(String[] args) {
    Car x = new Car();
    x.radioToggle();
    x.radioToggle();
    x.radioToggle();   
  }
}