@Override
  protected boolean nothingToCompare(@NotNull HgRepository repository) {
    final Map<String, LinkedHashSet<Hash>> branches = repository.getBranches();
    if (branches.size() > 1) return false;
    final Hash currentRevisionHash = getCurrentHash(repository);
    final Collection<HgNameWithHashInfo> other_bookmarks = getOtherBookmarks(repository, currentRevisionHash);
    if (!other_bookmarks.isEmpty()) return false;
    // if only one heavy branch and no other bookmarks -> check that current revision is not "main" branch head
    return currentRevisionHash.equals(getHeavyBranchMainHash(repository, repository.getCurrentBranch()));
  }
@Override
  protected boolean nothingToCompare(@NotNull HgRepository repository)