title: TypeError: search.valueChanges.debounceTime is not a function
body: <p>I am just learning angular2. At the time of applying something at input changes, I am getting the error.</p>
  
  <p>app.ts:</p>
  
  <pre><code>export class AppComponent {
      form: ControlGroup;
  
      constructor(fb: FormBuilder) {
          this.form = fb.group({
              search: []
          });
  
          var search = this.form.find('search');
          search.valueChanges
              .debounceTime(400)
              .map(str =&gt; (&lt;string&gt;str).replace(' ','‐'))
              .subscribe(x =&gt; console.log(x));
      };
  
   }
  </code></pre>
  
  <p>Error:</p>
  
  <p><a href="https://i.stack.imgur.com/N5Enw.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/N5Enw.jpg" alt="enter image description here"></a></p>
  
  <p>How to solve this? Am I missing something?</p>
  
  <p><a href="http://plnkr.co/edit/MQIQvFYAvsPv9Pu8xZap?p=preview" rel="noreferrer">Plunker Demo</a></p>
  
  <p><strong>N.B.</strong> I cannot produce anything at plunker as I am writing angular2 first time at plunker now. I have written only my app.ts code at plunker. I have showed the screenshot of error from my local pc. I will be grateful too if you tell me the way of running angular2 project at plunker.</p>