code: public Observable<Void> createOrUpdateAsync(String vaultName, String resourceGroupName, String fabricName, String containerName, String protectedItemName, ProtectedItemResourceInner parameters) {
          return createOrUpdateWithServiceResponseAsync(vaultName, resourceGroupName, fabricName, containerName, protectedItemName, parameters).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Enables backup of an item or to modifies the backup policy information of an already backed up item. This is an asynchronous operation. To know the status of the operation, call the GetItemOperationResult API.
  
  @param vaultName The name of the recovery services vault.
  @param resourceGroupName The name of the resource group where the recovery services vault is present.
  @param fabricName Fabric name associated with the backup item.
  @param containerName Container name associated with the backup item.
  @param protectedItemName Item name to be backed up.
  @param parameters resource backed up item
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceResponse} object if successful.