docs: def thumbnail(self):
          """Read-only attribute that provides the value of the thumbnail to display.
          """
          # check if there is a valid thumbnail override
          if self.thumbnail_override.id is not None:
              return self.thumbnail_override
  
          # otherwise, just try to grab the first image
          first_image = self.first_image
          if first_image is not None:
              return first_image
  
          # no override for thumbnail and no non-none image field, just return override,
          # which is a blank image field
          return self.thumbnail_override