code: func (sp *StandardProvider) Store() error {
  	if !sp.Ready() {
  		return errors.New("transport: provider does not have a key and certificate")
  	}
  
  	err := ioutil.WriteFile(sp.Paths.CertFile, sp.internal.certPEM, 0644)
  	if err != nil {
  		return err
  	}
  
  	return ioutil.WriteFile(sp.Paths.KeyFile, sp.internal.keyPEM, 0600)
  }
docs: // Store writes the key and certificate to disk, if necessary.