code: public Observable<DomainSharedAccessKeysInner> regenerateKeyAsync(String resourceGroupName, String domainName, String keyName) {
          return regenerateKeyWithServiceResponseAsync(resourceGroupName, domainName, keyName).map(new Func1<ServiceResponse<DomainSharedAccessKeysInner>, DomainSharedAccessKeysInner>() {
              @Override
              public DomainSharedAccessKeysInner call(ServiceResponse<DomainSharedAccessKeysInner> response) {
                  return response.body();
              }
          });
      }
docs: Regenerate key for a domain.
  Regenerate a shared access key for a domain.
  
  @param resourceGroupName The name of the resource group within the user's subscription.
  @param domainName Name of the domain
  @param keyName Key name to regenerate key1 or key2
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the DomainSharedAccessKeysInner object