cache_key

# File activerecord/lib/active_record/base.rb, line 1644
      def cache_key
        case
        when new_record?
          "#{self.class.model_name.cache_key}/new"
        when timestamp = self[:updated_at]
          timestamp = timestamp.utc.to_s(:number)
          "#{self.class.model_name.cache_key}/#{id}-#{timestamp}"
        else
          "#{self.class.model_name.cache_key}/#{id}"
        end
      end