code: public ServiceFuture<List<LongTermRetentionBackupInner>> listByLocationAsync(final String locationName, final ListOperationCallback<LongTermRetentionBackupInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              listByLocationSinglePageAsync(locationName),
              new Func1<String, Observable<ServiceResponse<Page<LongTermRetentionBackupInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<LongTermRetentionBackupInner>>> call(String nextPageLink) {
                      return listByLocationNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }
docs: Lists the long term retention backups for a given location.
  
  @param locationName The location of the database
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object