code: public Observable<Void> deleteImagesAsync(UUID projectId, List<String> imageIds) {
          return deleteImagesWithServiceResponseAsync(projectId, imageIds).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Delete images from the set of training images.
  
  @param projectId The project id
  @param imageIds Ids of the images to be deleted. Limted to 256 images per batch
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceResponse} object if successful.