gunicorn + fastapi

fastapi：

from fastapi import FastAPI
app = FastAPI()
@app.post("/tet")
async def root():
    return {"message": "Hello World"}

gunicorn：

`` `
gunicorn -k gevent --bind "0.0.0.0:8080" --log-level debug main：app

 ```
gunicorn -k tornado --bind "0.0.0.0:8080" --log-level debug main:app

エラー：

email-validator not installed, email fields will be treated as str.
To install, run: pip install email-validator
[2019-11-08 16:05:42 +0800] [12796] [DEBUG] 1 workers
[2019-11-08 16:05:49 +0800] [12799] [DEBUG] GET /tet
[2019-11-08 16:05:49 +0800] [12799] [ERROR] Error handling request /tet
Traceback (most recent call last):
  File "/home/ap/nlp/Anaconda3/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 56, in handle
    self.handle_request(listener_name, req, client, addr)
  File "/home/ap/nlp/Anaconda3/lib/python3.6/site-packages/gunicorn/workers/ggevent.py", line 160, in handle_request
    addr)
  File "/home/ap/nlp/Anaconda3/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 107, in handle_request
    respiter = self.wsgi(environ, resp.start_response)
TypeError: __call__() missing 1 required positional argument: 'send'