std::function<ChartLinks()> chartLinkGenerator =
      [startTs,
       endTs,
       this,
       chartLinksCache = std::
           unordered_map<std::pair<time_t, time_t>, ChartLinks>{}]() mutable {
        if (auto chartLinks = folly::get_optional(
                chartLinksCache, std::make_pair(startTs, endTs))) {
          LOG(INFO) << "got from cache"  << " "<< startTs;
          return *chartLinks;
        }
        auto chartLinks = genChartLinks(startTs, endTs);
        LOG(INFO) << "not got from cache ";
        chartLinksCache.emplace(std::make_pair(startTs, endTs), chartLinks);
        return chartLinks;
      };


for (int i=0;i<=100;i++) {

    auto result =   alertGenerator_->foo(chartLinkGenerator);

}