presto-main/src/main/java/io/prestosql/sql/gen/OrderingCompiler.java/OrderingCompiler/compilePageWithPositionComparator
class OrderingCompiler:    public PageWithPositionComparator compilePageWithPositionComparator(List<Type> sortTypes, List<Integer> sortChannels, List<SortOrder> sortOrders)
    {
        requireNonNull(sortTypes, "sortTypes is null");
        requireNonNull(sortChannels, "sortChannels is null");
        requireNonNull(sortOrders, "sortOrders is null");

        return pageWithPositionComparators.getUnchecked(new PagesIndexComparatorCacheKey(sortTypes, sortChannels, sortOrders));
    }