package app;

class App {
  private static int OFF = 0;
  private static int ON = 1;
  static int state = OFF;

  public static void up() {
    state++;
  }

  public static void down() {
    state--;
  }

  public static void expect_max() {
    assert state == 10;
  }

  public static void expect_on(int val) {
    assert state==val;
  }

  public static void expect_off() {
    assert state == 0;
  }
}


