internal server error

起了sanic, 訪問http://localhost:3289/pop失敗
```
{"description":"Internal Server Error","status":500,"message":"The server encountered an internal error and cannot complete your request."}
```

Start by running the Sanic server and requesting http://localhost:3289/pop as described in the issue. Inspect the resulting server traceback and the implementation serving the /pop endpoint to identify why it returns HTTP 500. Done means the endpoint responds successfully instead of returning the internal-server-error response.

Written by the indexing model from the issue text.