code: func (sm *SignedManifest) Signatures() ([][]byte, error) {
  	jsig, err := libtrust.ParsePrettySignature(sm.all, "signatures")
  	if err != nil {
  		return nil, err
  	}
  
  	// Resolve the payload in the manifest.
  	return jsig.Signatures()
  }
docs: // Signatures returns the signatures as provided by
  // (*libtrust.JSONSignature).Signatures. The byte slices are opaque jws
  // signatures.