anchor.diff:  :marked
     Notice that `TestBed.configureTestingModule` no longer provides a (fake) `HeroService` because it's [not needed](#stub-hero-detail-service).
   
  -  注意，`TestBed.configureTestingModule`不再提供（伪造）`HeroService`，因为它是[没必要的](#stub-hero-detail-service)。
  +  注意，`TestBed.configureTestingModule`不再提供（伪造）`HeroService`，因为已经[没有必要了](#stub-hero-detail-service)。
   
   #override-component-method
   :marked
  
positive.code:   Those are providers for the _testing module_, not the component. They prepare the dependency injector at the _fixture level_.
  
    在`TestBed.configureTestingModule`的`providers`中stub伪造组件的`HeroDetailService`是不可行的。
    这些是**测试模块**的提供商，而非组件的。它们在**fixture级别**准备依赖注入器。
  
    Angular creates the component with its _own_ injector which is a _child_ of the fixture injector.
    It registers the component's providers (the `HeroDetailService` in this case) with the child injector. 
  
negative.code: 
      Fortunately, the `HeroDetailService` delegates responsibility for remote data access to an injected `HeroService`.
  
      幸运的是，`HeroDetailService`将远程数据访问的责任交给了注入进来的`HeroService`。
  
    +makeExample('testing/ts/app/hero/hero-detail.service.ts', 'prototype', 'app/hero/hero-detail.service.ts (prototype)')(format='.')
    :marked
  