presto-main/src/main/java/io/prestosql/operator/aggregation/minmaxby/MinMaxByNStateSerializer.java/MinMaxByNStateSerializer/MinMaxByNStateSerializer
class MinMaxByNStateSerializer:    public MinMaxByNStateSerializer(BlockComparator blockComparator, Type keyType, Type valueType)
    {
        this.blockComparator = blockComparator;
        this.keyType = keyType;
        this.valueType = valueType;
        this.serializedType = TypedKeyValueHeap.getSerializedType(keyType, valueType);
    }