presto-main/src/main/java/io/prestosql/execution/SqlTaskExecution.java/Status/incrementRemainingDriver
class Status:        public synchronized void incrementRemainingDriver(Lifespan lifespan)
        {
            checkState(!isNoMoreDriverRunners(lifespan), "Cannot increment remainingDriver for Lifespan %s. NoMoreSplits is set.", lifespan);
            per(lifespan).remainingDriver++;
            overallRemainingDriver++;
        }