presto-main/src/main/java/io/prestosql/operator/OrderByOperator.java/OrderByOperator/duplicate
class OrderByOperator:        @Override
        public OperatorFactory duplicate()
        {
            return new OrderByOperatorFactory(
                    operatorId,
                    planNodeId,
                    sourceTypes,
                    outputChannels,
                    expectedPositions,
                    sortChannels,
                    sortOrder,
                    pagesIndexFactory,
                    spillEnabled,
                    spillerFactory,
                    orderingCompiler);
        }