presto-record-decoder/src/main/java/io/prestosql/decoder/json/JsonRowDecoderFactory.java/JsonRowDecoderFactory/chooseFieldDecoders
class JsonRowDecoderFactory:    private Map<DecoderColumnHandle, JsonFieldDecoder> chooseFieldDecoders(Set<DecoderColumnHandle> columns)
    {
        return columns.stream()
                .collect(toImmutableMap(identity(), this::chooseFieldDecoder));
    }