>>591 どぅ?

private void doWork(int stage) {
  if (stage == 0) break;
  if (stage > 0) method_1();
  if (stage > 1) method_2();
  if (stage >= 3){
    if (stage == 3) {
      method_3();
    } else {
      method_4();
    }
  }
}