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