How to intercept the response in angular 4 with HttpInterceptor -

i have following interceptor:

@injectable() export class tokeninterceptor implements httpinterceptor {    constructor(private tokenservice: tokenservice) { }    intercept(req: httprequest<any>, next: httphandler): observable<httpevent<any>> {     const token = this.tokenservice.gettoken();      if (token) {       const authreq = req.clone({         headers: req.headers.set('authorization', `bearer ${token}`)       });        return next.handle(authreq);     }      return next       .handle(req) //       .getsomehowtheresponse()       .andsavethetokeninstorage()       .andpropagatenexttheresponse()   } } 

and want save token response header in local storage, tutorials showing how intercept request, not response.

next.handle(req) returns observable can subscribe it:

return next.handle(req).map((event: httpevent<any>) => {   if (event instanceof httpresponse) {     // stuff response , headers want     event.headers     event.body   } })