code: public Observable<Void> unregisterAsync(String resourceGroupName, String vaultName, String identityName) {
          return unregisterWithServiceResponseAsync(resourceGroupName, vaultName, identityName).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Unregisters the given container from your Recovery Services vault.
  
  @param resourceGroupName The name of the resource group associated with the Recovery Services vault.
  @param vaultName The name of the Recovery Services vault.
  @param identityName Name of the protection container to unregister.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceResponse} object if successful.