presto-main/src/main/java/io/prestosql/operator/TaskOutputOperator.java/TaskOutputOperatorFactory/createOperator
class TaskOutputOperatorFactory:        @Override
        public Operator createOperator(DriverContext driverContext)
        {
            OperatorContext operatorContext = driverContext.addOperatorContext(operatorId, planNodeId, TaskOutputOperator.class.getSimpleName());
            return new TaskOutputOperator(operatorContext, outputBuffer, pagePreprocessor, serdeFactory);
        }