presto-main/src/main/java/io/prestosql/operator/aggregation/minmaxby/MinMaxByNStateFactory.java/GroupedMinMaxByNState/getTypedKeyValueHeap
class GroupedMinMaxByNState:        @Override
        public TypedKeyValueHeap getTypedKeyValueHeap()
        {
            return heaps.get(getGroupId());
        }