presto-main/src/main/java/io/prestosql/operator/OperationTimer.java/OperationTimer/end
class OperationTimer:    void end(OperationTiming overallTiming)
    {
        requireNonNull(overallTiming, "overallTiming is null");
        checkState(!finished, "timer is finished");
        finished = true;

        long cpuEnd = trackOverallCpuTime ? currentThreadCpuTime() : 0;
        long wallEnd = System.nanoTime();

        overallTiming.record(nanosBetween(wallStart, wallEnd), nanosBetween(cpuStart, cpuEnd));
    }