presto-main/src/main/java/io/prestosql/operator/NestedLoopBuildOperator.java/NestedLoopBuildOperator/duplicate
class NestedLoopBuildOperator:        @Override
        public OperatorFactory duplicate()
        {
            return new NestedLoopBuildOperatorFactory(operatorId, planNodeId, nestedLoopJoinBridgeManager);
        }