Cherrypy REST教程返回TypeError：_expose（）只需要1个参数

Question

尝试在cherrypy文档页面上按照教程7来创建REST样式API。来自tutorial，

的复制粘贴代码

import random
import string

import cherrypy

@cherrypy.expose
class StringGeneratorWebService(object):

    @cherrypy.tools.accept(media='text/plain')
    def GET(self):
        return cherrypy.session['mystring']

    def POST(self, length=8):
        some_string = ''.join(random.sample(string.hexdigits, int(length)))
        cherrypy.session['mystring'] = some_string
        return some_string

    def PUT(self, another_string):
        cherrypy.session['mystring'] = another_string

    def DELETE(self):
        cherrypy.session.pop('mystring', None)


if __name__ == '__main__':
    conf = {
        '/': {
            'request.dispatch': cherrypy.dispatch.MethodDispatcher(),
            'tools.sessions.on': True,
            'tools.response_headers.on': True,
            'tools.response_headers.headers': [('Content-Type',    'text/plain')],
        }
    }
    cherrypy.quickstart(StringGeneratorWebService(), '/', conf)

但是在运行时给出了错误

File "H:/researchInstrumentCatalog/dqapi/core/test.py", line 36, in <module>
cherrypy.quickstart(test(), '/', conf)
TypeError: expose_() takes exactly 1 argument (0 given) 

我正在运行cherrypy 3.8，因此this question没有帮助