code: private <T> Observable<PollingState<T>> updateStateFromGetResourceOperationAsync(final PollingState<T> pollingState, String url) {
          return pollAsync(url, pollingState.loggingContext())
                  .flatMap(new Func1<Response<ResponseBody>, Observable<PollingState<T>>>() {
                      @Override
                      public Observable<PollingState<T>> call(Response<ResponseBody> response) {
                          try {
                              pollingState.updateFromResponseOnPutPatch(response);
                              return Observable.just(pollingState);
                          } catch (CloudException | IOException e) {
                              return Observable.error(e);
                          }
                      }
                  });
      }
docs: Polls from the provided URL and updates the polling state with the
  polling response.
  
  @param pollingState the polling state for the current operation.
  @param url the url to poll from
  @param <T> the return type of the caller.