如何在Angular API请求中传递报头中的x-api-key？[副本]

Question

import { Injectable } from '@angular/core';
import { Http, Headers, RequestOptions, Response } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map';

@Injectable()
export class InsuranceServiceService {

  public token: string;
  constructor(private http: Http) {
    const currentUser = JSON.parse(localStorage.getItem('currentUser'));
    this.token = currentUser && currentUser.token;
   }

  createAuthorizationHeader(headers: Headers) {
    headers.append('Content-Type', 'application/json');
    headers.append('x-api-key', `xxxxxxxxxxxxxxxxxxxx`);
  }

  sendOTP(data: object): Observable<Object[]> {
    const header = new Headers();
    this.createAuthorizationHeader(header);
    return this.http.post('http://my-omain.com/', data, 
    {
      headers: header
    })
    .map((response: Response) => response.json());
  }

}