code: func (d *driver) PutContent(ctx context.Context, subPath string, contents []byte) error {
  	writer, err := d.Writer(ctx, subPath, false)
  	if err != nil {
  		return err
  	}
  	defer writer.Close()
  	_, err = io.Copy(writer, bytes.NewReader(contents))
  	if err != nil {
  		writer.Cancel()
  		return err
  	}
  	return writer.Commit()
  }
docs: // PutContent stores the []byte content at a location designated by "path".