Ruby on rails 4 添加'；克隆'；路由到现有restful控制器

我正在尝试将此方法添加到restful控制器（还有以下工作方法：index、：new、：create、：edit、：update和：destroy）：

如何为“admin/class_section/：id/clone”添加路由

namespace :admin do    
  get "class_sections/:id/clone", to: "class_sections#clone", as: "class_sections_clone"
end

Utg::Application.routes.draw do

  devise_for :users
  root to: "home#index"
  namespace :admin do
    resources :class_sections, except: [:show]
  end

  resources :class_sections, only: [:index, :show]
end

namespace :admin do    
  get "class_sections/:id/clone", to: "class_sections#clone", as: "class_sections_clone"
end