code: public Observable<AppInner> updateAsync(String resourceGroupName, String resourceName, AppPatch appPatch) {
          return updateWithServiceResponseAsync(resourceGroupName, resourceName, appPatch).map(new Func1<ServiceResponse<AppInner>, AppInner>() {
              @Override
              public AppInner call(ServiceResponse<AppInner> response) {
                  return response.body();
              }
          });
      }
docs: Update the metadata of an IoT Central application.
  
  @param resourceGroupName The name of the resource group that contains the IoT Central application.
  @param resourceName The ARM resource name of the IoT Central application.
  @param appPatch The IoT Central application metadata and security metadata.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request