code: function(event) {
        this.currentNb++;
        if (this.currentNb < this.length) pingAll(connList);
        //to avoid mysql2 taking all the server memory
        if (promiseMysql2 && promiseMysql2.clearParserCache)
          promiseMysql2.clearParserCache();
        if (mysql2 && mysql2.clearParserCache) mysql2.clearParserCache();
        console.log(event.target.toString());
        const drvType = event.target.options.drvType;
        const benchTitle =
          event.target.options.benchTitle +
          ' ( sql: ' +
          event.target.options.displaySql +
          ' )';
        const iteration = 1 / event.target.times.period;
        const variation = event.target.stats.rme;
  
        if (!bench.reportData[benchTitle]) {
          bench.reportData[benchTitle] = [];
        }
        if (drvType !== 'warmup') {
          bench.reportData[benchTitle].push({
            drvType: drvType,
            iteration: iteration,
            variation: variation
          });
        }
      }
docs: called between running benchmarks