class NonCapturing {
  public static void main(String... args) {
    run(NonCapturing::sayHi);
  }
  private static void run(Runnable run) {
    run.run();
  }
  private static void sayHi() {
    System.out.println("Hey!");
  }
}

class Capturing {
  public static void main(Capturing instance) {
    run(instance::sayHi);
  }
  private static void run(Runnable run) {
    run.run();
  }
  void sayHi() {
    System.out.println("Hey!");
  }
}