问如何修复tornado.wsgi中的"TypeError：__call__()接受2个位置参数但给出了3个“？

EN

# app/__init__.py

import tornado.wsgi
import tornado.web
import wsgiref.simple_server


class MainHandler(tornado.web.RequestHandler):
    def get(self):
        self.render("templates/index.html")

def routes():
    return [
    (r"/", MainHandler),
]

class Application(tornado.wsgi.WSGIContainer):
    def __init__(self):
        handlers = routes()

        tornado.wsgi.WSGIContainer.__init__(self, handlers)

# wsgi.py 

import wsgiref.simple_server
from app import Application

application = Application()
server = wsgiref.simple_server.make_server('', 8888, Application())
server.serve_forever()

Traceback (most recent call last):
  File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/wsgiref/handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
TypeError: __call__() takes 2 positional arguments but 3 were given
127.0.0.1 - - [10/Aug/2019 17:40:58] "GET / HTTP/1.1" 500 59