code: func (s *Signer) SigAlgo() x509.SignatureAlgorithm {
  	if s.local != nil {
  		return s.local.SigAlgo()
  	}
  
  	// currently remote.SigAlgo just returns
  	// x509.UnknownSignatureAlgorithm.
  	return s.remote.SigAlgo()
  }
docs: // SigAlgo returns the RSA signer's signature algorithm.