docs: private Long calculateRequestLatency(TimingInfo timingInfo) {
          if (timingInfo == null) {
              return null;
          }
  
          TimingInfo httpClientSendRequestTime = timingInfo.getLastSubMeasurement(AWSRequestMetrics.Field.HttpClientSendRequestTime
                                                                                      .name());
          TimingInfo httpClientReceiveResponseTime = timingInfo.getLastSubMeasurement(AWSRequestMetrics.Field
                                                                                          .HttpClientReceiveResponseTime.name());
          if (httpClientSendRequestTime != null && httpClientSendRequestTime.getTimeTakenMillisIfKnown() != null &&
              httpClientReceiveResponseTime != null && httpClientReceiveResponseTime.getTimeTakenMillisIfKnown() != null) {
              return httpClientSendRequestTime.getTimeTakenMillisIfKnown().longValue()
                     + httpClientReceiveResponseTime.getTimeTakenMillisIfKnown().longValue();
          }
          return null;
      }