Angular2/Http (POST) headers

I'm unable to change the headers when doing a POST request. I tried a couple of things:

Simple class:

export class HttpService {
    constructor(http: Http) {
        this._http = http;
    }
}

I tried:

testCall() {
    let body = JSON.stringify(
        { "username": "test", "password": "abc123" }
    )

    let headers = new Headers();
    headers.append('Content-Type', 'application/json'); // also tried other types to test if its working with other types, but no luck

    this._http.post('http://mybackend.local/api/auth', body, { 
        headers: headers 
    })
    .subscribe(
        data => { console.log(data); },
        err => { console.log(err); },
        {} => { console.log('complete'); }
    );
}

testCall() {
    let body = JSON.stringify(
        { "username": "test", "password": "abc123" }
    )

    let headers = new Headers();
    headers.append('Content-Type', 'application/json'); // also tried other types to test if its working with other types, but no luck

    let options = new RequestOptions({
        headers: headers
    });

    this._http.post('http://mybackend.local/api/auth', body, options)
    .subscribe(
        data => { console.log(data); },
        err => { console.log(err); },
        {} => { console.log('complete'); }
    );
}

none of the two are working. I didn't forget to import any of the classes.

I'm using Google Chrome. So I check the 'Network' tab, my request is there, and it says my Content-Type is text/plain.

Is this a bug or am I doing something wrong?

UPDATE I forgot to import the Headers class from Angular2/http:

import {Headers} from 'angular2/http';

I think you're using the HTTP support of Angular2 the right way. See this working plunkr: https://plnkr.co/edit/Y777Dup3VnxHjrGSbsr3?p=preview.

Perhaps, you forgot to import the Headers class. I made this mistake some time ago and there was no error in the JavaScript console but the headers I tried to set weren't actually set. For example regarding the Content-Type header I had text/plain instead of application/json. You can reproduce this in the plunkr I provided to you by commenting Headers in the imports...

Here is a complete working sample (imports included):

import {Component} from 'angular2/core';
import {Http,Headers} from 'angular2/http';
import 'rxjs/Rx';

@Component({
  selector: 'my-app', 
  template: `
    <div (click)="executeHttp()">
      Execute HTTP
    </div>
  `
})
export class AppComponent {
  constructor(private http:Http) {

  }

  createAuthorizationHeader(headers:Headers) {
    headers.append('Authorization', 'Basic ' +
      btoa('a20e6aca-ee83-44bc-8033-b41f3078c2b6:c199f9c8-0548-4be79655-7ef7d7bf9d20')); 
  }

  executeHttp() {
    var headers = new Headers();
    this.createAuthorizationHeader(headers);
    headers.append('Content-Type', 'application/json');

    var content = JSON.stringify({
      name: 'my name'
    });

    return this.http.post(
      'https://angular2.apispark.net/v1/companies/', content, {
        headers: headers
      }).map(res => res.json()).subscribe(
        data => { console.log(data); },
        err => { console.log(err); }
      );
  }
}

Hope it helps you, Thierry