*Wouldn't be nice if this could save the new type of the record, if it has a "type" column (single table inheritance)?
*>> a = Account.find 2 => #<Account id: 2 ...> >> a.becomes(ManagerAccount) => #<ManagerAccount id: 2 ...> >> a.save => true >> a = Account.find 2 => #<Account id: 2 ...>**