presto-main/src/main/java/io/prestosql/operator/TableScanOperator.java/TableScanOperator/createOperator
class TableScanOperator:        @Override
        public SourceOperator createOperator(DriverContext driverContext)
        {
            checkState(!closed, "Factory is already closed");
            OperatorContext operatorContext = driverContext.addOperatorContext(operatorId, sourceId, getOperatorType());
            return new TableScanOperator(
                    operatorContext,
                    sourceId,
                    pageSourceProvider,
                    table,
                    columns);
        }