title: Angular2 exception: Token must be defined
body: <p>app/boot.ts</p>
  
  <pre><code>import {bootstrap} from 'angular2/platform/browser';
  import {AppComponent} from './app.component';
  bootstrap(AppComponent);
  </code></pre>
  
  <p>app/app.component.ts</p>
  
  <pre><code>import {Component} from 'angular2/core';
  @Component({
    selector: 'my-app',
    template: '{{title}}'
  })
  class AppComponent {
    title: "app"
  }
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>EXCEPTION: Token must be defined!
  STACKTRACE:BrowserDomAdapter.logError @ angular2.dev.js:23514
  ExceptionHandler.call                 @ angular2.dev.js:1147
  (anonymous function)                  @ angular2.dev.js:14801
  NgZone._notifyOnError                 @ angular2.dev.js:5796
  collection_1.StringMapWrapper.merge.onError @ angular2.dev.js:5700
  run                                   @ angular2-polyfills.js:141
  (anonymous function)                  @ angular2.dev.js:5719
  NgZone.run                            @ angular2.dev.js:5681
  ApplicationRef_.bootstrap             @ angular2.dev.js:14906
  bootstrap                             @ angular2.dev.js:25054
  execute                               @ boot.ts:4
  u                                     @ system.src.js:4597
  execute                               @ system.src.js:4597
  y                                     @ system.src.js:4597
  ...
  </code></pre>