presto-main/src/main/java/io/prestosql/util/MergeSortedPages.java/MergeSortedPages/mergeSortedPages
class MergeSortedPages:    public static WorkProcessor<Page> mergeSortedPages(
            List<WorkProcessor<Page>> pageProducers,
            PageWithPositionComparator comparator,
            List<Type> outputTypes,
            AggregatedMemoryContext aggregatedMemoryContext,
            DriverYieldSignal yieldSignal)
    {
        return mergeSortedPages(
                pageProducers,
                comparator,
                IntStream.range(0, outputTypes.size()).boxed().collect(toImmutableList()),
                outputTypes,
                (pageBuilder, pageWithPosition) -> pageBuilder.isFull(),
                false,
                aggregatedMemoryContext,
                yieldSignal);
    }