code: public Observable<WebhookInner> updateAsync(String resourceGroupName, String registryName, String webhookName, WebhookUpdateParameters webhookUpdateParameters) {
          return updateWithServiceResponseAsync(resourceGroupName, registryName, webhookName, webhookUpdateParameters).map(new Func1<ServiceResponse<WebhookInner>, WebhookInner>() {
              @Override
              public WebhookInner call(ServiceResponse<WebhookInner> response) {
                  return response.body();
              }
          });
      }
docs: Updates a webhook with the specified parameters.
  
  @param resourceGroupName The name of the resource group to which the container registry belongs.
  @param registryName The name of the container registry.
  @param webhookName The name of the webhook.
  @param webhookUpdateParameters The parameters for updating a webhook.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request