singleton_method_undefined

Invoked as a callback whenever a singleton method is undefined in the receiver.

   module Chatty
     def Chatty.singleton_method_undefined(id)
       puts "Undefining #{id.id2name}"
     end
     def Chatty.one()   end
     class << self
        undef_method(:one)
     end
   end

produces:

   Undefining one