+
+ old_way = OldWay.from_way(self)
+ old_way.timestamp = t
+ old_way.save_with_dependencies!
+ end
+ end
+
+ def update_from(new_way, user)
+ check_consistency(self, new_way, user)
+ if !new_way.preconditions_ok?
+ raise OSM::APIPreconditionFailedError.new