new_contents: import celery
  
  from sorl.thumbnail import default
  from sorl.thumbnail.images import ImageFile
  
  @celery.task
  def create_thumbnail(image_file, geometry_string, **options):
      source = ImageFile(image_file)
      for key, value in default.backend.default_options.iteritems():
              options.setdefault(key, value)
      name = default.backend._get_thumbnail_filename(source, geometry_string, options)
      thumbnail = ImageFile(name, default.storage)
      source_image = default.engine.get_image(source)
      default.backend._create_thumbnail(source_image, geometry_string, options, thumbnail)
  
      size = default.engine.get_image_size(source_image)
      source.set_size(size)
  
      default.kvstore.get_or_set(source)
      default.kvstore.set(thumbnail, source)
subject: add celery task to create thumbnail