code: private boolean isManyToOne() {
      StackTraceElement[] trace = Thread.currentThread().getStackTrace();
      if (trace.length >= 9) {
        for (int i = 6; i <= 8; i++) {
          if (trace[i].getClassName().equals("org.hibernate.cfg.ToOneFkSecondPass")) return true;
        }
      }
      return false;
    }
docs: 检查是否为ManyToOne调用