public function sortAscending(array $prefList)
    {
        $comparator = new MatchedPreferenceComparator();

        usort(
            $prefList,
            function (MatchedPreferenceInterface $lValue, MatchedPreferenceInterface $rValue) use ($comparator) {
                return -1 * $comparator->compare($lValue, $rValue);
            }
        );

        return $prefList;
    }