How to add "acts as" plugin

module Contactable
   def self.append_features(klass)
      super
      klass.extend(Macros)
   end
   
   def Macros
      def acts_as_contactable
         extend ClassMethods
         include InstanceMethods
      end
   end
   
   module ClassMethods
   end
   
   module InstanceMethods
   end
end