code: func loadCAPool(path string) (*x509.CertPool, error) {
  	caPool := x509.NewCertPool()
  	f, err := os.Open(path)
  	if err != nil {
  		return nil, err
  	}
  	defer f.Close()
  
  	b, err := ioutil.ReadAll(f)
  	if err != nil {
  		return nil, err
  	}
  
  	if !caPool.AppendCertsFromPEM(b) {
  		return nil, errors.New("CACertFile parsing failed")
  	}
  
  	return caPool, nil
  }
docs: // loadCAPool will load a valid x509 cert.