anchor.diff:  
   === The Hero Service
   
  -We also need a `HeroService` to be able to retrive the heroes list in our Angular application. Add `app/hero.service.ts` file:
  +We also need a [classname]#HeroService# to be able to retrive the heroes list in our Angular application. Add [filename]#app/hero.service.ts# file:
   
   [source,typescript]
   .app/hero.service.ts
  
positive.code: export class AppComponent { }
  ----
  
  Save changes and launch the development server to see the results in your browser. After loading, your application have this look:
  
  [[figure.app.layout]]
  .A Screenshot of Empty Application Layout
  image::img/app-layout.png[width="432",height="644"]
  
  Now your application has a layout made by using `app-header-layout`, `app-header` and `app-toolbar`.
  
  === Elements Used in This Step
  
  `app-header-layout`:: The application layout consisting of the `app-header` and the main contents. In our case, it adds a scrollable container for the application contents as well.
  
  `app-header`:: Acts as a header in the application layout. The header is fixed in our application.
  
  `app-toolbar`:: Provides a toolbar wrapper.
  
  [NOTE]
  .app-layout Elements are Design-Agnostic
  ====
  Polymer elements from `app-layout` set, including `app-toolbar` that we use, are design-agnostic. They do not enforce have Material Design look by default, though still support it. Therefore we need to adjust `app-toolbar` styles a bit.
  
  Therefore we added color rules for the `app-toolbar` in the styles of the `AppComponent`. We reuse the color values of default theme from `paper-styles`.
  
  Apart from the colors, it inherits the font family declared for the body. We have already decleared our font settings for the body in `index.html` earliear during this step.
  ====
  
  [IMPORTANT]
  .PolymerElement Directives
  ====
  In order to enable all features of Polymer elements used inside your Angular component templates, remember to import `PolymerElement` in the component file and add `PolymerElement('element-name')` line for each Polymer element you use to the `directives` array of your component metadata.
  ====
  
  == List Heroes with Vaadin Grid
  
  In the previous step we added the application layout with `app-layout` elements. Next we are going add actual application content. Our plan is to use Vaadin Grid to list Heroes.
  
  [NOTE]
  .Some Parts are Explained in the Tour of Heroes
  ====
  This step partly follows the Angular 2 Tour of Heroes Tutorial. Therefore here we skip explaining the parts of the code that are similar in both this tutorial and the Tour of Heroes, like the `Hero` class and the `HeroService`.
  
  See https://angular.io/docs/ts/latest/tutorial/[Tour of Heroes] for the detailed explainations of these parts.
  ====
  
  === Hero Class
  
  Let us start with creating the `Hero` class. Add `app/hero.ts` file with the following contents:
  
  [source,typescript]
  .app/hero.ts
  
negative.code: 
  Clone the https://github.com/angular/quickstart[QuickStart repository] into the tutorial project folder:
  
  [subs="normal"]
  ----
  [prompt]#$# [command]#git# clone https://github.com/angular/quickstart my-project
  [prompt]#$# [command]#cd# my-project
  ----
  
  We are not going to contribute to the quickstart repository itself, so the original repository data is not needed. Remove the git repository data folder:
  
  [subs="normal"]
  ----
  [prompt]#$# [command]#rm# -rf .git
  ----
  
  === Starting from the QuickStart ZIP Package
  
  Alternatively, instead of using git to clone the QuickStart repository, you can download and extract the https://github.com/angular/quickstart/archive/master.zip[QuickStart zip package].
  
  === Remove the AppComponent Tests
  
  The QuickStart respository contains tests for [classname]#AppComponent#. Unfortunately, some changes to [classname]#AppComponent# in the following steps are going to break the compilation for these tests.
  
  Please remove the [filename]#app/app.component.spec.ts# file to prevent its compilation errors introduced later in this tutorial.
  
  [NOTE]
  .Testing in Angular 2
  