code: func (n *node) GetBytes(bucketName string, key interface{}) ([]byte, error) {
  	id, err := toBytes(key, n.codec)
  	if err != nil {
  		return nil, err
  	}
  
  	var val []byte
  	return val, n.readTx(func(tx *bolt.Tx) error {
  		raw, err := n.getBytes(tx, bucketName, id)
  		if err != nil {
  			return err
  		}
  
  		val = make([]byte, len(raw))
  		copy(val, raw)
  		return nil
  	})
  }
docs: // GetBytes gets a raw value from a bucket.