private static boolean isSupported(@NotNull DiffRequest request) {
    if (request.getUserData(ChangeDiffRequestProducer.CHANGE_KEY) != null) return true;

    ContentDiffRequest contentRequest = ObjectUtils.tryCast(request, ContentDiffRequest.class);
    if (contentRequest == null) return false;

    List<DiffContent> contents = contentRequest.getContents();
    if (contents.size() != 2) return false;

    for (DiffContent content : contents) {
      boolean canShow = content instanceof DocumentContent ||
                        content instanceof EmptyContent;
      if (!canShow) return false;
    }
    return true;
  }
private static boolean isSupported(@NotNull DiffRequest request)