presto-main/src/main/java/io/prestosql/operator/SimplePagesIndexComparator.java/SimplePagesIndexComparator/SimplePagesIndexComparator
class SimplePagesIndexComparator:    public SimplePagesIndexComparator(List<Type> sortTypes, List<Integer> sortChannels, List<SortOrder> sortOrders)
    {
        this.sortTypes = ImmutableList.copyOf(requireNonNull(sortTypes, "sortTypes is null"));
        this.sortChannels = ImmutableList.copyOf(requireNonNull(sortChannels, "sortChannels is null"));
        this.sortOrders = ImmutableList.copyOf(requireNonNull(sortOrders, "sortOrders is null"));
    }