title: How to subscribe on custom model Angular 2?
body: <p>I have got the following custom model:</p>
  
  <pre><code>export class CreateEducationYear {
  
    public year: number;
    public name: string;
  
  }
  </code></pre>
  
  <p>I use this in component like this:</p>
  
  <pre><code>public newEducationYearModel: Observable&lt;CreateEducationYear&gt;;
  constructor() {
     this.newEducationYearModel = new  Observable&lt;CreateEducationYear&gt;();
  }
  
  // Subscribe method
  
  public test(): Observable&lt;CreateEducationYear&gt; {
     return this.newEducationYearModel;
  }
  
  // Listening
  
  ngOnInit() {
      this.test().subscribe(data =&gt; {
        console.log(data);
      });
    }
  </code></pre>
  
  <p>I get an error: </p>
  
  <blockquote>
    <p>TypeError: Cannot read property 'subscribe' of undefined</p>
  </blockquote>
  
  <p>What do I do wrong?</p>
  
  <p>Template is:</p>
  
  <pre><code>{{newEducationYearModel | json }}
  &lt;div class="filter-search-item-sub col-md-3"&gt;
      &lt;label&gt;Название периода&lt;/label&gt;
      &lt;input [(ngModel)]="newEducationYearModel.name" name="period" type="text" value=""/&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>After first launch I see <code>CreateEducationYear {year: 2000}</code> in console. But further when I change model nothing changes.</p>