title: Observable returned by service won't complete
body: <p>I have a service that uses angular's http service</p>
  
  <pre><code>@Injectable()
  export class MyService {
  
    constructor(private http: Http) { }
  
    getThings() {
      return this.http.get('url').map((res) =&gt; {
        // massage data here and return massaged data
      });
    }
  }
  </code></pre>
  
  <p>I use the service like this </p>
  
  <pre><code>this.myService.getThings.subscribe(
    things =&gt; {},
    err =&gt; {},
    () =&gt; {
      // never completes...
    });
  </code></pre>
  
  <p>How come <code>myService.getThings()</code> never completes although <code>http.get('url')</code> completes ?</p>
  
  <p>How can I make <code>myService.getThings()</code> complete ?</p>