protected function aggregate() : array
    {
        $ret = [];

        if ($this->flags & Benchmark::BENCHMARK_TIME === Benchmark::BENCHMARK_TIME){
            $ret['time'] = TimeBenchmark::score($this->h_time);
        }
        if ($this->flags & Benchmark::BENCHMARK_MEMORY === Benchmark::BENCHMARK_MEMORY){
            $ret['memory'] = MemoryBenchmark::score($this->h_memory);
        }
        return $ret;
    }