code: def router(self):
          
          if not self.has_root_router:
              self.middleware.add(HTTPMethod.ALL,
                                  MiddlewareChain.ROOT_PATTERN,
                                  Router())
          return self.middleware.last().func
docs: Property returning the router at the top of the middleware
          chain's stack (the last item in the list). If the list is empty
          OR the item is not an instance of growler.Router, one is created
          and added to the middleware chain, matching all requests.