angular 2 http services

   request(url: string | Request, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `get` http method.
     */
    get(url: string, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `post` http method.
     */
    post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>;
    /**
     * Performs a request with `put` http method.
     */