code: public Observable<ServiceResponse<AppInner>> updateWithServiceResponseAsync(String resourceGroupName, String resourceName, AppPatch appPatch) {
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (resourceName == null) {
              throw new IllegalArgumentException("Parameter resourceName is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          if (appPatch == null) {
              throw new IllegalArgumentException("Parameter appPatch is required and cannot be null.");
          }
          Validator.validate(appPatch);
          Observable<Response<ResponseBody>> observable = service.update(this.client.subscriptionId(), resourceGroupName, resourceName, this.client.apiVersion(), appPatch, this.client.acceptLanguage(), this.client.userAgent());
          return client.getAzureClient().getPutOrPatchResultAsync(observable, new TypeToken<AppInner>() { }.getType());
      }
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