docs: public Observable<CognitiveServicesAccountKeysInner> regenerateKeyAsync(String resourceGroupName, String accountName) {
          return regenerateKeyWithServiceResponseAsync(resourceGroupName, accountName).map(new Func1<ServiceResponse<CognitiveServicesAccountKeysInner>, CognitiveServicesAccountKeysInner>() {
              @Override
              public CognitiveServicesAccountKeysInner call(ServiceResponse<CognitiveServicesAccountKeysInner> response) {
                  return response.body();
              }
          });
      }