code: public Observable<Page<MediaServiceInner>> listByResourceGroupNextAsync(final String nextPageLink) {
          return listByResourceGroupNextWithServiceResponseAsync(nextPageLink)
              .map(new Func1<ServiceResponse<Page<MediaServiceInner>>, Page<MediaServiceInner>>() {
                  @Override
                  public Page<MediaServiceInner> call(ServiceResponse<Page<MediaServiceInner>> response) {
                      return response.body();
                  }
              });
      }
docs: List Media Services accounts.
  List Media Services accounts in the resource group.
  
  @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;MediaServiceInner&gt; object