code: func (sp *StandardProvider) SetCertificatePEM(certPEM []byte) error {
  	cert, err := helpers.ParseCertificatePEM(certPEM)
  	if err != nil {
  		return errors.New("transport: invalid certificate")
  	}
  
  	sp.internal.certPEM = certPEM
  	sp.internal.cert = cert
  	return nil
  }
docs: // SetCertificatePEM receives a PEM-encoded certificate and loads it
  // into the provider.