def update_cache(cache_rule)
      cache_rule.each do |type, type_methods|
        type_methods.each do |method|
          value = self.send(type).send(method)
          self.cache["#{type}_#{method}"] = value
        end
      end
      save
    end
def update_cache(cache_rule)
      cache_rule.each do |type, type_methods|
        type_methods.each do |method|
          value = self.send(type).send(method)
          self.cache["#{type}_#{method}"] = value
        end
      end
      save
    end
TODO: Untested