# File lib/state_machine/integrations/mongo_mapper/versions.rb, line 43
        def define_state_accessor
          owner_class.key(attribute, String) unless owner_class.keys.include?(attribute)
          
          name = self.name
          owner_class.validates_each(attribute, :logic => lambda {|*|
            machine = self.class.state_machine(name)
            machine.invalidate(self, :state, :invalid) unless machine.states.match(self)
          })
        end