# File lib/state_machine/machine.rb, line 1603
      def define_state_accessor
        attribute = self.attribute
        
        @helper_modules[:instance].class_eval { attr_reader attribute } unless owner_class_ancestor_has_method?(:instance, attribute)
        @helper_modules[:instance].class_eval { attr_writer attribute } unless owner_class_ancestor_has_method?(:instance, "#{attribute}=")
      end