Back in the day I recall that NotImplementedError was used for metaprogramming dynamic methods - in particular the ActiveRecord helpers that translated to semi-

Back in the day I recall that NotImplementedError was used for metaprogramming dynamic methods - in particular the ActiveRecord helpers that translated to semi-natural language based on fields in the db... it would try to create the method on the fly if the fields existed and the convention was adhered to, otherwise it would rethrow. I don't believe those are supported anymore.