anchor.diff:    ### 应用路由
   
   +makeExample('ngmodule/ts/src/app/app-routing.module.ts', '', 'src/app/app-routing.module.ts')(format='.')
  +
   :marked
     The router is the subject of the [Routing & Navigation](router.html) page, so this section skips many of the details and
     concentrates on the intersection of NgModules and routing.
  
positive.code:   下面是新的`ContactModule`：
  
  +makeExample('ngmodule/ts/src/app/contact/contact.module.2.ts', '', 'src/app/contact/contact.module.ts')
  :marked
    You copy from `AppModule` the contact-related import statements and `@NgModule` properties
    that concern the contact, and paste them into `ContactModule`.
  
negative.code:   把`FormsModule`加到`AppModule`元数据中的`imports`列表中：
  
  +makeExample('ngmodule/ts/src/app/app.module.1.ts', 'imports')(format=".")
  
  :marked
    Now `[(ngModel)]` binding will work and the user input will be validated by Angular forms,
    once you declare the new component, pipe, and directive.
  