title: Angular 2 Observable.forkJoin this._subscribe is not a function in [null]
body: <p>I have this Angular2 Component, where I try to make two HTTP parallel requests to with PersonServie (that works fine). But the <code>Observable.forkJoin</code> method throws this error: <code>EXCEPTION: TypeError: this._subscribe is not a function in [null]</code></p>
  
  <p>Evaluating <code>getIdentificationTypes()</code> and <code>getPerson()</code> function, each return an <code>Observable</code> object.</p>
  
  <p>What am I missing?</p>
  
  <pre><code> import { Component, OnInit } from 'angular2/core';
      import { Router, RouteParams } from 'angular2/router';
      import {ROUTER_DIRECTIVES, ROUTER_PROVIDERS} from 'angular2/router';
      import { Observable } from 'rxjs/Rx';
      import 'rxjs/Rx';
  
      // more imports for models and other components//
  
  
      @Component({
          selector: 'my-coponent',
          templateUrl: 'template',
          directives: [ROUTER_DIRECTIVES]
      })
  
      export class MyComponent implements OnInit {
             public identificationTypes: IdentificationType[];
             public person : Person;
         // some public and private properties here //
  
          constructor(
              private _router: Router,
              private  _routeParams : RouteParams,
              private _personService: PersonServie
          ){}
  
          ngOnInit() {
              let id= (this._routeParams.get('id'));
              this._id= id? +id: 0;
  
              Observable.forkJoin([
                 this.getIdentificationTypes(),
                 this.getPerson(this._id)
              ]).subscribe(data =&gt;{
                  this.identificationTypes= data[0];
                  this.person= data[1];              
              });
          }
  
          private getIdentificationTypes(){
              return this._generalService.getIdentifiacitonTypes();
          }
  
          private getPerson(person: number){
              if(athleteId == 0){                
                  let person = new Person();
                  return Observable.create(person );
              }
  
  
              return this._personService.getPerson(athleteId);
          }
  }
  </code></pre>