code: func (bs *blobStore) path(dgst digest.Digest) (string, error) {
  	bp, err := pathFor(blobDataPathSpec{
  		digest: dgst,
  	})
  
  	if err != nil {
  		return "", err
  	}
  
  	return bp, nil
  }
docs: // path returns the canonical path for the blob identified by digest. The blob
  // may or may not exist.