private static List<MavenIndex> getOldIndices(@NotNull RepositoryDiff<MavenIndex> localDiff,
                                                @NotNull RepositoryDiff<List<MavenIndex>> remoteDiff) {
    List<MavenIndex> oldIndices = new ArrayList<>(remoteDiff.oldIndices);
    if (localDiff.oldIndices != null) oldIndices.add(localDiff.oldIndices);
    return oldIndices;
  }
private static List<MavenIndex> getOldIndices(@NotNull RepositoryDiff<MavenIndex> localDiff,
                                                @NotNull RepositoryDiff<List<MavenIndex>> remoteDiff)