code: public Observable<Page<GeoRegionInner>> listGeoRegionsNextAsync(final String nextPageLink) {
          return listGeoRegionsNextWithServiceResponseAsync(nextPageLink)
              .map(new Func1<ServiceResponse<Page<GeoRegionInner>>, Page<GeoRegionInner>>() {
                  @Override
                  public Page<GeoRegionInner> call(ServiceResponse<Page<GeoRegionInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get a list of available geographical regions.
  Get a list of available geographical regions.
  
  @param nextPageLink The NextLink from the previous successful call to List operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;GeoRegionInner&gt; object