anchor.diff:      We've setup the initial route configuration. Now we'll add it to our `AppModule`.
       We'll add our configured `RouterModule` to the `AppModule` imports !{_array}.
   
  +    我们设置了初始路由配置。现在把它添加到`AppModule`里。添加配置好的`RouterModule`到`AppModule`的`imports`数组中。
  +
     +makeExcerpt('app/app.module.2.ts (app routing)', '')
   
     .l-sub-section
  
positive.code: :marked
    ## Refactor routes to a _Routing Module_
  
    Almost 20 lines of `AppModule` are devoted to configuring four routes. 
    Most application have many more routes and they [add guard services](../guide/router.html#guards) 
    to protect against unwanted or unauthorized navigations. 
    Routing considerations could quickly dominate this module and obscure its primary purpose which is to 
    establish key facts about the entire app for the Angular compiler.
  
    We should refactor the routing configuration into its own class.
    What kind of class? 
    The current `RouterModule.forRoot()` produces an Angular `ModuleWithProviders` which suggests that a
    class dedicated to routing should be some kind of module.
    It should be a [_Routing Module_](../guide/router.htm#routing-module).
  
    By convention the name of a _Routing Module_ contains the word "Routing" and 
    aligns with the name of the module that declares the components navigated to".
    
    Create an `app-routing.module.ts` file as a sibling to `app.module.ts`. Give it the following contents extracted from the `AppModule` class:
  
  +makeExample('app/app-routing.module.ts')
  :marked
    Noteworthy points, typical of _Routing Modules_:
    * Pull the routes into a variable. You might export it in future and it clarifies the _Routing Module_ pattern.
  
    * Add `RouterModule.forRoot(routes)` to `imports`.
      
    * Add `RouterModule` to `exports` so that the components in the companion module have access to Router declarables 
    such as `RouterLink` and `RouterOutlet`.
    
    * No `declarations`!  Declarations are the responsibility of the companion module.
  
    * Add module `providers` for guard services if you have them; there are none in this example.
  
    ### Update _AppModule_
  
    Now delete the routing configuration from `AppModule` and import the `AppRoutingModule` 
    (_both_ with an ES `import` statement _and_ by adding it to the `NgModule.imports` list).
  
    Here is the revised `AppModule`, compared to its pre-refactor state:
  +makeTabs(
    `toh-5/ts/app/app.module.ts, toh-5/ts/app/app.module.3.ts`,
     null,
  
negative.code: :marked
    It's simpler and focused on indentifying the key pieces of the application.  
  
    它更简单，专注于确定应用的关键部分。
  
  .l-main-section
  :marked
    ## Select a Hero in the *HeroesComponent*
  