anchor.diff:  
     We generally recommend registering application-wide services in the root `AppComponent` *providers*.
     Here we're registering in `main` for a special reason.
  -  
  -  Our application is in the early stages of development and far from ready for production. 
  +
  +  Our application is in the early stages of development and far from ready for production.
     We don't even have a web server that can handle requests for heroes.
     Until we do, *we'll have to fake it*.
  -  
  +
     We're going to *trick* the http client into fetching and saving data from
     a demo/development service, the *in-memory web api*.
  -  
  +
     The application itself doesn't need to know and shouldn't know about this.
     So we'll slip the *in-memory web api* into the configuration *above* the `AppComponent`.
  -  
  +
     Here is a version of `main` that performs this trick
  -+makeExample('toh-6/ts/app/main.ts', 'final', 'app/main.ts (final)')(format=".")  
  ++makeExample('toh-6/ts/app/main.ts', 'final', 'app/main.ts (final)')(format=".")
   
   :marked
     We're replacing the default `XHRBackend`, the service that talks to the remote server,
  
positive.code: :marked
    The application runs and updates automatically as we continue to build the Tour of Heroes.
  
  .l-main-section  
  :marked
   ## Prepare for Http
    
    `Http` is ***not*** a core Angular module. 
    It's Angular's optional approach to web access and it exists as a separate add-on module called `@angular/http`,
    shipped in a separate script file as part of the Angular npm package. 
    
    Fortunately we're ready to import from `@angular/http` because `systemjs.config` configured *SystemJS* to load that library when we need it.
  
  :marked
    ### Register (provide) *http* services
    Our app will depend upon the Angular `http` service which itself depends upon other supporting services.
    The `HTTP_PROVIDERS` array from `@angular/http` library holds providers for the complete set of http services.
    
    We should be able to access these services from anywhere in the application.
    So we register them in the `bootstrap` method of `main.ts` where we
    launch the application and its root `AppComponent`.
    
  +makeExample('toh-6/ts/app/main.ts','v1','app/main.ts (v1)')(format='.')
  :marked
    Notice that we supply the `HTTP_PROVIDERS` in an array as the second parameter to the `bootstrap` method.
  
negative.code: 
  :marked
    # Getting and Saving Data with HTTP
  
    Our stakeholders appreciate our progress.
    Now they want to get the hero data from a server, let users add, edit, and delete heroes,
    and save these changes back to the server.
  
    In this chapter we teach our application to make the corresponding http calls to a remote server's web api.
  :marked
    [Run the live example](/resources/live-examples/toh-6/ts/plnkr.html).
  
  .l-main-section
  :marked
    ## Where We Left Off
  