anchor.diff:    
     We solve the problem by relocating the `Hero` class from `app.component.ts` to its own `hero.ts` file.
   
  -+makeExample('toh-3/ts/app/hero.ts', null, 'hero.ts (Exported Hero class)')(format=".")
  ++makeExample('toh-3/ts/app/hero.ts', '', 'app/hero.ts')(format=".")
   
   :marked
     We export the `Hero` class from `hero.ts` because we'll need to reference it in both component files. 
  -  Add the following import statement near the top of both `app.component.ts` and `hero-detail.component.ts`.
  -
  -+makeExample('toh-3/ts/app/hero-detail.component.ts', 'hero-import', 'hero-detail.component.ts and app.component.ts (Import the Hero class)')
  +  Add the following import statement near the top of **both `app.component.ts` and `hero-detail.component.ts`**.
  +
  ++makeExample('toh-3/ts/app/hero-detail.component.ts', 'hero-import')
   
   :marked
     #### The *hero* property is an ***input***
  
positive.code:   ### Keep the app transpiling and running
    We want to start the TypeScript compiler, have it watch for changes, and start our server. We'll do this by typing
  
  code-example(format="." language="bash").
    npm start
  
  :marked
  
negative.code:     
      All of our component names end in "Component".  All of our component file names end in ".component".
      
      We spell our file names in lower **[dash case](../guide/glossary.html#!#dash-case)** 
      (AKA **[kebab-case](../guide/glossary.html#!#kebab-case)**) so we don't worry about
      case sensitivity on the server or in source control.
  
      <!-- TODO
  