code: public AppInner beginUpdate(String resourceGroupName, String resourceName, AppPatch appPatch) {
          return beginUpdateWithServiceResponseAsync(resourceGroupName, resourceName, appPatch).toBlocking().single().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
  @throws ErrorDetailsException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the AppInner object if successful.