code: func (n *node) Set(bucketName string, key interface{}, value interface{}) error {
  	var data []byte
  	var err error
  	if value != nil {
  		data, err = n.codec.Marshal(value)
  		if err != nil {
  			return err
  		}
  	}
  
  	return n.SetBytes(bucketName, key, data)
  }
docs: // Set a key/value pair into a bucket