code: def wsgi_middleware(self, app, cors=False):
          
          _app = StaticServerMiddleware(app, '/' + self.prefix, self.path,
                                        cors=self.cors)
  
          def app(environ, start_response):
              if not hasattr(self, 'host_url'):
                  self.host_url = (environ['wsgi.url_scheme'] + '://' +
                                   environ['HTTP_HOST'] + '/')
              return _app(environ, start_response)
          return app
docs: WSGI middlewares that wraps the given ``app`` and serves
          actual image files. ::
  
              fs_store = HttpExposedFileSystemStore('userimages', 'images/')
              app = fs_store.wsgi_middleware(app)
  
          :param app: the wsgi app to wrap
          :type app: :class:`~typing.Callable`\ [[],
              :class:`~typing.Iterable`\ [:class:`bytes`]]
          :returns: the another wsgi app that wraps ``app``
          :rtype: :class:`StaticServerMiddleware`