code: func (bs *blobStore) readlink(ctx context.Context, path string) (digest.Digest, error) {
  	content, err := bs.driver.GetContent(ctx, path)
  	if err != nil {
  		return "", err
  	}
  
  	linked, err := digest.Parse(string(content))
  	if err != nil {
  		return "", err
  	}
  
  	return linked, nil
  }
docs: // readlink returns the linked digest at path.