public static string synchronize(bool isJS, IDriver driver, IEnumerable<BuildIds> buildIds, IEnumerable<Langs> locs) {
var src = buildEnvelopes.adjust();
var dest = driver.readMap();
var delta = src.synchronize(dest, isJS, buildIds, locs);
if (delta == null) return "Up-to-date";
driver.update(delta);
return string.Format("Deleted: {0}, updated: {1}, inserted: {2}", delta.delete.Count, delta.update.Count, delta.insert.Count);
}