title: How to use custom pipes in Angular 2
body: <p>So I was following this post <a href="https://stackoverflow.com/questions/35534959/access-key-and-value-of-object-using-ngfor">access key and value of object using *ngFor</a> </p>
  
  <p>However I'm getting a 'pipe could not be found error'.</p>
  
  <ul>
  <li><p>I've done this <code>@Pipe({name: 'keys'})</code> </p></li>
  <li><p>I've exported the class. </p></li>
  <li><p>I've imported it in my app.module.ts</p></li>
  <li><p>I've put it in the declarations</p></li>
  <li><p>I've included it in my app.component.ts (where I'm using it)</p></li>
  </ul>
  
  <p>What else am I missing?</p>