code: public Observable<Void> offlineRegionAsync(String resourceGroupName, String accountName, String region) {
          return offlineRegionWithServiceResponseAsync(resourceGroupName, accountName, region).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Offline the specified region for the specified Azure Cosmos DB database account.
  
  @param resourceGroupName Name of an Azure resource group.
  @param accountName Cosmos DB database account name.
  @param region Cosmos DB region, with spaces between words and each word capitalized.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request