# File lib/spruz/memoize.rb, line 51
      def memoize_function(*function_ids)
        mc = @__memoize_cache__ ||= {}
        function_ids.each do |method_id|
          method_id = method_id.to_s.to_sym
          orig_method = instance_method(method_id)
          __send__(:define_method, method_id) do |*args|
            if mc.key?(method_id) and result = mc[method_id][args]
              result
            else
              (mc[method_id] ||= {})[args] = result = orig_method.bind(self).call(*args)
              $DEBUG and warn "#{self.class} cached function #{method_id}(#{args.inspect unless args.empty?}) = #{result.inspect}"
            end
            result
          end
        end
      end