似乎有return语句，后面的类型推断有问题

<img width="2033" height="656" alt="Image" src="https://github.com/user-attachments/assets/59090699-7308-434a-b781-9e825f2804ec" />

<img width="1319" height="398" alt="Image" src="https://github.com/user-attachments/assets/b582dcf3-0319-4693-94e7-13106b7aabca" />
一样的self， 第二个self判断的类型是unknown