public ListBoxModel doFillImageIdItems(@RelativePath("..") @QueryParameter String authToken)
        throws Exception {

      SortedMap<String, Image> availableImages = DigitalOcean.getAvailableImages(authToken);
      ListBoxModel model = new ListBoxModel();

      for (Map.Entry<String, Image> entry : availableImages.entrySet()) {
        final Image image = entry.getValue();

        // For non-snapshots, use the image ID instead of the slug (which isn't available anyway)
        // so that we can build images based upon backups.
        final String value = DigitalOcean.getImageIdentifier(image);

        model.add(entry.getKey(), value);
      }

      return model;
    }