anchor.diff:    When the data arrive it pushes the new hero object into its `heroes` array for presentation to the user.
   +makeExample('server-communication/ts/app/toh/hero-list.component.ts', 'addHero', 'app/toh/hero-list.component.ts (addHero)')(format=".")
   
  +<a id="promises"></a>
   :marked
     ## Fall back to Promises
     
  
positive.code:     The `Subscription` object has a different purpose, signified by its primary method, `unsubscribe`.
      
      Learn more about observables to understand the implications and consequences of subscriptions.
  :marked
    ## Get data with `JSONP`
  
  
negative.code:   :
  +makeExample('server-communication/ts/app/main.ts', 'import-rxjs', 'app/main.ts (import rxjs)')(format=".")
  :marked
    <a id="map"></a>
    ### Map the response object
    Let's come back to the `HeroService` and look at the `http.get` call again to see why we needed `map()`
  +makeExample('server-communication/ts/app/toh/hero.service.ts', 'http-get-v1', 'app/toh/hero.service.ts (http.get)')(format=".")
  