Sometimes you wish to convert one STI class to another, e.g. promote User to Administrator.
ActiveRecord::Base#becomes(Klass) returns an instance of the current record converted to the specified Klass, e.g.:
user = User.find_by_login("sam")
user.becomes(Administrator)
Note however that this does not change the type attribute of the instance, so you still have an additional step to do if you want this [...]