public static void main(String... args) {
    Main point = new Main(0, 0);

    new Thread(
            () -> {
              for (int i = 0; i < 20; i++) {
                int x = point.getX();
                int y = point.getY();
                if (x != y) {
                  System.err.printf("O_o %d %d \n", x, y);
                }
              }
            })
        .start();

    for (int i = 0; i < 2_000; i++) {
      for (int j = 0; j < 100; j++) {
        point.setX(j);
        point.setY(j);
      }
    }
  }