headers: HttpHeaders;
  httpOptions;

  constructor(private http: HttpClient) {
    const token = localStorage.getItem("token");
    this.headers = new HttpHeaders({
      "Content-Type": "application/x-www-form-urlencoded"
    }).set("x-auth-token", token);

    this.httpOptions = {
      headers: this.headers,
      responseType: "json",
      observe: "response"
    };
  }

  test<T>(url: string) {
    return this.http.get<T>(url, this.httpOptions).pipe(
      map((res: HttpResponse<any>) => {
      console.log(res.headers);
      })
    );
  }