presto-redis/src/main/java/io/prestosql/plugin/redis/decoder/hash/HashRedisRowDecoderFactory.java/HashRedisRowDecoderFactory/create
class HashRedisRowDecoderFactory:    @Override
    public RowDecoder create(Map<String, String> decoderParams, Set<DecoderColumnHandle> columns)
    {
        requireNonNull(columns, "columns is null");
        return new HashRedisRowDecoder(chooseFieldDecoders(columns));
    }