func convertFromAnnotation(se *parquettypes.SchemaElement, v interface{}) (interface{}, error) {
	if se == nil {
		return v, nil
	}

	var value interface{}
	switch val := v.(type) {
	case []byte:
		// TODO: only strings are supported in s3select output (not
		// binary arrays) - perhaps we need to check the annotation to
		// ensure it's UTF8 encoded.
		value = string(val)
	case [12]byte:

	return &Reader{
		args:       args,
		decoder:    d,
		valueCh:    d.Stream(),
		readCloser: readCloser,
	}
}

// syncReadCloser will wrap a readcloser and make it safe to call Close while
// reads are running.
type syncReadCloser struct {
	rc io.ReadCloser
	mu sync.Mutex
}

func (pr *syncReadCloser) Read(p []byte) (n int, err error) {
	// This ensures that Close will block until Read has completed.

		r.csvDstPool.Put(r.current)
		r.current = <-item.dst
		r.err = item.err
		r.recordsRead = 0
	}
	csvRecord := r.current[r.recordsRead]
	r.recordsRead++

	// If no column names are set, use _(index)
	if r.columnNames == nil {
		r.columnNames = make([]string, len(csvRecord))
		for i := range csvRecord {
			r.columnNames[i] = fmt.Sprintf("_%v", i+1)
		}
	}

	// If no index map, add that.

// A Reader wraps an io.Reader and computes the MD5 checksum
// of the read content as ETag. Optionally, it also computes
// the SHA256 checksum of the content.
//
// If the reference values for the ETag and content SHA26
// are not empty then it will check whether the computed
// match the reference values.
type Reader struct {
	src         io.Reader
	bytesRead   int64
	expectedMin int64
	expectedMax int64

	size       int64

		close(r.decoded)
		readCloser.Close()
		for range r.input {
			// Read until EOF trickles through.
			// Otherwise, we risk the decoder hanging.
		}
		r.readerWg.Done()
	}

	// We cannot reuse as we are sending parsed objects elsewhere.
	simdjson.ParseNDStream(readCloser, r.input, nil)
	r.readerWg.Add(1)
	go r.startReader()
	return &r
}

// NewElementReader - creates new JSON reader using readCloser.