code: private void enforceCpuLimits()
      {
          for (QueryExecution query : queryTracker.getAllQueries()) {
              Duration cpuTime = query.getTotalCpuTime();
              Duration sessionLimit = getQueryMaxCpuTime(query.getSession());
              Duration limit = Ordering.natural().min(maxQueryCpuTime, sessionLimit);
              if (cpuTime.compareTo(limit) > 0) {
                  query.fail(new ExceededCpuLimitException(limit));
              }
          }
      }
docs: Enforce query CPU time limits