List<MavenIndex> (@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; }