title: Angular2 Observable.forkJoin of observable variables - ReferenceError: Observable is not defined
body: <p>I'd like to ask you for help. I omitted code that I assume is not important. Let's imagine TS file that contains service calls:</p>
  
  <p>// file: someService.ts</p>
  
  <pre><code>@Injectable()
  export class SomeService {
       method1(){
           var observable = this.http.get(someUrl)
                            .map((res: Response) =&gt;&lt;MyClass[]&gt;res.json());
           return observable;
       }
  
       method2(){
           // Similar to method1
       }
  }
  </code></pre>
  
  <p>// file: someComponent.ts</p>
  
  <p>Please note, that this.method1observable and method2observable are properly assigned from parent (root) component and their type is Observable. </p>
  
  <pre><code>import {Observable}     from 'rxjs/Observable';
  
  export class SomeClass {
      public m1: Observable&lt;MyClass[]&gt;;
      public m2: Observable&lt;AnotherClass[]&gt;
  
      ngOnInit() {
          Observable.forkJoin(this.m1,this.m2) //&lt;- ERROR HERE
          .subscribe(data =&gt; {
              this.myFunction(data[0], data[1]);
              requestAnimationFrame(this.renderLoop);
          });
      }
  }
  </code></pre>
  
  <p>I get <strong>"Uncaught ReferenceError: Observable is not defined"</strong>.
  Don't you know what am I doing wrong? I saw some examples where Observable.forkJoin is called inside a service. But what if I want to call it inside a component?</p>