public @NotNull Couple<HgRevisionNumber> parents(@NotNull VirtualFile repo, @Nullable FilePath file, @Nullable HgRevisionNumber revision) {
    final List<HgRevisionNumber> revisions = getRevisions(repo, "parents", file, revision, true);
    return switch (revisions.size()) {
      case 1 -> Couple.of(revisions.get(0), null);
      case 2 -> Couple.of(revisions.get(0), revisions.get(1));
      default -> Couple.of(null, null);
    };
  }
public @NotNull Couple<HgRevisionNumber> parents(@NotNull VirtualFile repo, @Nullable FilePath file, @Nullable HgRevisionNumber revision)