Angular 2 - How do I write a Http get promise?

I'm importing http and want to set the http header with my auth token.
Then I want to write a http get and put the response into a promise to return to the method that calls it.

So far I have this:

 import {Http, Headers} from angular2/http;

 import {EnvironmentService} from './environmentService';



 export class AuthService {

     private environmentService: EnvironmentService;

     private http: Http;

     private header: Headers;



     contructor(_environmentService: EnvironmentService, _http: Http, _header: Headers){

         this.environmentService = _environmentService;

         this.http = _http;



         this.header.append('Authorization', '1234');  

         this.header.append('Content-Type', 'application/json');      

     }



     getSpotifyData = ():Promise<Object> => {

         return this.http

           .get('http://ws.spotify.com/search/1/track.json?q=foo',             {headers:this.header})

           .map((response) => {

             return response.json()

           })

           .toPromise();

     }



 }

Thanks in advance!