title: angular2 service method not getting invoked
body: <p>I tried to create a sample angular2 service and consume it, but I am not sure about the mistake that i have done. the service method couldn't be called by the component, Please see the plunker for more details  <a href="https://plnkr.co/edit/tlnGU9Er6GxsOaUMCZZG?p=preview" rel="nofollow">https://plnkr.co/edit/tlnGU9Er6GxsOaUMCZZG?p=preview</a></p>
  
  <p>My service code looks like below</p>
  
  <pre><code>import { Injectable } from 'angular2/core';
  import { HTTP_PROVIDERS, Http, Headers, Response, JSONP_PROVIDERS, Jsonp } from 'angular2/http';
  import { Configuration } from './Configuration';
  import 'rxjs/add/operator/map'
  import { Observable } from 'rxjs/Observable';
  
  ///Service class to call REST API
  @Injectable()
  export class SampleService {
      items: Array&lt;any&gt;;
  
      constructor() {
          this.items = [
              { name: 'Test1' },
              { name: 'Test2' },
              { name: 'Test3' }
          ];
      }
  
      getItems() {
          return this.items;
      }
  }
  </code></pre>