private static IResponse getResponse(IRequest newRequest) {
        return (IResponse) Observable.concat(
                Observable.just(newRequest)
                        .map(r ->Try.of(()->cacheResource.getResponse(r)))
                        .filter(Try::isSuccess)
                        .map(Try::get),
                Observable.just(newRequest)
                        .map(r ->Try.of(()->fileResource.getResponse(r)))
                        .filter(Try::isSuccess)
                        .map(Try::get)
        ).first(null);
    }