title: Observable.map - Supplied parameter does not match any signature of call target
body: <p>I have an angular 2 application. Upgraded from <code>rxjs-5.0.0-beta.12</code> to <code>rxjs-5.1.0</code> but now below <code>this.http.get(...).map()</code> shows an error. </p>
  
  <blockquote>
    <p>Supplied parameters do not match any signature of call target</p>
  </blockquote>
  
  <pre><code>import { Http, Headers } from '@angular/http';
  import { Observable } from 'rxjs/Observable';
  import 'rxjs/add/operator/map';
  import 'rxjs/add/operator/catch';
  
  export class BaseService {
      private baseUrl: string = 'http://someserver:8080/somedb';
  
      constructor(public http: Http) {}
  
      doGet(url: string, headers?: Headers): Observable&lt;any&gt; {
          if(headers) {
              return this.http.get(this.baseUrl+url, {headers: headers}).map(response =&gt; {
  
              }, err =&gt; {
  
              });
  
          }
      }
  
  }
  </code></pre>
  
  <p>Error only occurs when adding the <code>.map()</code>, did something change in the release?</p>
  
  <p>Full IDE message:</p>
  
  <pre><code>[ts] Supplied parameters do not match any signature of call target.
  Applies a given project function to each value emitted by the source
  Observable, and emits the resulting values as an Observable.
  
  &lt;span class="informal"&gt;Like Array.prototype.map(),
  it passes each source value through a transformation function to get
  corresponding output values.&lt;/span&gt;
  
  &lt;img src="./img/map.png" width="100%"&gt;
  
  Similar to the well known Array.prototype.map function, this operator
  applies a projection to each value and emits that projection in the output
  Observable.
  
  @example &lt;caption&gt;Map every every click to the clientX position of that click&lt;/caption&gt;
  var clicks = Rx.Observable.fromEvent(document, 'click');
  var positions = clicks.map(ev =&gt; ev.clientX);
  positions.subscribe(x =&gt; console.log(x));
  
  @see {@link mapTo}
  @see {@link pluck}
  
  @return {Observable&lt;R&gt;} An Observable that emits the values from the source
  Observable transformed by the given project function.
  @method map
  @owner Observable
  
  (property) Observable&lt;Response&gt;.map: &lt;T, R&gt;() =&gt; any
  </code></pre>