@Override
    public boolean canShowContent(@NotNull DiffContent content, @NotNull DiffContext context) {
      if (content instanceof DocumentContent) return true;
      if (content instanceof FileContent) {
        VirtualFile file = ((FileContent)content).getFile();
        if (!file.isValid()) return false;
        if (DiffUtil.isFileWithoutContent(file)) return false;
        return true;
      }
      return false;
    }
@Override
    public boolean canShowContent(@NotNull DiffContent content, @NotNull DiffContext context)