presto-benchmark/src/main/java/io/prestosql/benchmark/DoubleSumAggregationBenchmark.java/DoubleSumAggregationBenchmark/createOperatorFactories
class DoubleSumAggregationBenchmark:    @Override
    protected List<? extends OperatorFactory> createOperatorFactories()
    {
        OperatorFactory tableScanOperator = createTableScanOperator(0, new PlanNodeId("test"), "orders", "totalprice");
        Metadata metadata = createTestMetadataManager();
        InternalAggregationFunction doubleSum = metadata.getAggregateFunctionImplementation(metadata.resolveFunction(QualifiedName.of("sum"), fromTypes(DOUBLE)));
        AggregationOperatorFactory aggregationOperator = new AggregationOperatorFactory(1, new PlanNodeId("test"), Step.SINGLE, ImmutableList.of(doubleSum.bind(ImmutableList.of(0), Optional.empty())), false);
        return ImmutableList.of(tableScanOperator, aggregationOperator);
    }