code: func (s *storage) makeSingleMetaBlob(plainBR, encBR blob.Ref, plainSize uint32) []byte {
  	plain := fmt.Sprintf("#camlistore/encmeta=2\n%s/%d/%s\n", plainBR, plainSize, encBR)
  	return s.encryptBlob(nil, []byte(plain))
  }
docs: // makeSingleMetaBlob makes and encrypts a metaBlob with one entry.