This method requires arguments in Rails 3.x and doesn't appear to be valid when used like this. More detail is necessary, but since this changed from Rails 2.3 (which allowed the call without arguments), it looked safe to remove this.

Since you're using ActiveSupport::Concern, which was introduced in Rails 3, I was able to deduce that you're using Rails 3 to power this code. How this worked in Rails 3.x is still a mystery to me.