This might have also been never added because the `destroy!` instance method wasn't added until 4faaa81

+1 for no transaction; the relation `create!` method only runs transactions around each `create!` instead of around the collection:

https://github.com/fabiokr/rails/blob/e0bf9c5f2f6315be9271b793a6a5132ffc52327e/activerecord/lib/active_record/relation.rb#L142