code: public Observable<ServiceResponse<BuildTaskInner>> updateWithServiceResponseAsync(String resourceGroupName, String registryName, String buildTaskName, BuildTaskUpdateParameters buildTaskUpdateParameters) {
          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 (registryName == null) {
              throw new IllegalArgumentException("Parameter registryName is required and cannot be null.");
          }
          if (buildTaskName == null) {
              throw new IllegalArgumentException("Parameter buildTaskName is required and cannot be null.");
          }
          if (buildTaskUpdateParameters == null) {
              throw new IllegalArgumentException("Parameter buildTaskUpdateParameters is required and cannot be null.");
          }
          Validator.validate(buildTaskUpdateParameters);
          final String apiVersion = "2018-02-01-preview";
          Observable<Response<ResponseBody>> observable = service.update(this.client.subscriptionId(), resourceGroupName, registryName, buildTaskName, apiVersion, buildTaskUpdateParameters, this.client.acceptLanguage(), this.client.userAgent());
          return client.getAzureClient().getPutOrPatchResultAsync(observable, new TypeToken<BuildTaskInner>() { }.getType());
      }
docs: Updates a build task 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 buildTaskName The name of the container registry build task.
  @param buildTaskUpdateParameters The parameters for updating a build task.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request