anchor.diff:    :marked
       Notice the `@Injectable()` #{_decorator} above the service class.
       We'll discuss its purpose [shortly](#injectable).
  +
  +    注意服务类上面这个`@Injectable()`装饰器。我们[很快](#injectable)会讨论它的用途。
   
   - var _perhaps = _docsFor == 'dart' ? '' : 'perhaps';
   .l-sub-section
  
positive.code: .l-main-section#explicit-injector
  :marked
    ## Appendix: Working with injectors directly
    ### 附录：直接使用注入器工作
  
    We rarely work directly with an injector.
    Here's an `InjectorComponent` that does.
  
negative.code:   which makes this object play the logger role.
  
    于是我们可以通过`useValue`选项来注册一个供应商，它会让这个对象直接扮演logger的角色。
  
  - var stylePattern = { otl: /(useValue: \w*)/gm };
  +makeExample('dependency-injection/ts/app/providers.component.ts','providers-7', '', stylePattern)(format=".")
  