class ActionDispatch::Routing::RouteSet::Dispatcher

def serve(req)
  params     = req.path_parameters
  controller = controller req
  res        = controller.make_response! req
  dispatch(controller, params[:action], req, res)
rescue ActionController::RoutingError
  if @raise_on_name_error
    raise
  else
    [404, { Constants::X_CASCADE => "pass" }, []]
  end
end