presto-main/src/main/java/io/prestosql/operator/AssignUniqueIdOperator.java/AssignUniqueIdOperator/AssignUniqueIdOperatorFactory
class AssignUniqueIdOperator:        public AssignUniqueIdOperatorFactory(
                int operatorId,
                PlanNodeId planNodeId)
        {
            this.operatorId = operatorId;
            this.planNodeId = requireNonNull(planNodeId, "planNodeId is null");
        }