presto-main/src/main/java/io/prestosql/execution/SqlTaskExecution.java/SqlTaskExecution/updateMaxScheduledPlanNodeOrdinalIfNecessary
class SqlTaskExecution:        public void updateMaxScheduledPlanNodeOrdinalIfNecessary(int scheduledPlanNodeOrdinal)
        {
            if (maxScheduledPlanNodeOrdinal < scheduledPlanNodeOrdinal) {
                maxScheduledPlanNodeOrdinal = scheduledPlanNodeOrdinal;
            }
        }