code: public Observable<DomainInner> updateAsync(String resourceGroupName, String domainName, Map<String, String> tags) {
          return updateWithServiceResponseAsync(resourceGroupName, domainName, tags).map(new Func1<ServiceResponse<DomainInner>, DomainInner>() {
              @Override
              public DomainInner call(ServiceResponse<DomainInner> response) {
                  return response.body();
              }
          });
      }
docs: Update a domain.
  Asynchronously updates a domain with the specified parameters.
  
  @param resourceGroupName The name of the resource group within the user's subscription.
  @param domainName Name of the domain
  @param tags Tags of the domains resource
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request