# File lib/mini_profiler/storage/memcache_store.rb, line 26
      def set_unviewed(user, id)
        @client.add("#{@prefix}-#{user}-v", [], @expires_in_seconds)
        MAX_RETRIES.times do
          break if @client.cas("#{@prefix}-#{user}-v", @expires_in_seconds) do |ids|
            ids << id unless ids.include?(id)
            ids
          end
        end
      end