docs: public ServiceFuture<List<BackupEngineBaseResourceInner>> getAsync(final String vaultName, final String resourceGroupName, final String filter, final String skipToken, final ListOperationCallback<BackupEngineBaseResourceInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              getSinglePageAsync(vaultName, resourceGroupName, filter, skipToken),
              new Func1<String, Observable<ServiceResponse<Page<BackupEngineBaseResourceInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<BackupEngineBaseResourceInner>>> call(String nextPageLink) {
                      return getNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }