code: func CaCerts(certs ...string) Option {
  	return func(c *CredHub) error {
  		// TODO: remove else block once x509.SystemCertPool is supported on Windows
  		// see: https://github.com/golang/go/issues/16736
  		var pool *x509.CertPool
  		if runtime.GOOS != "windows" {
  			var err error
  			pool, err = x509.SystemCertPool()
  			if err != nil {
  				return err
  			}
  		} else {
  			pool = x509.NewCertPool()
  		}
  		c.caCerts = pool
  
  		for _, cert := range certs {
  			ok := c.caCerts.AppendCertsFromPEM([]byte(cert))
  			if !ok {
  				return errors.New("provided ca certs are invalid")
  			}
  		}
  
  		return nil
  	}
  }
docs: // CaCerts specifies the root certificates for HTTPS connections with the CredHub server.
  //
  // If the OAuthStrategy is used for Auth, the root certificates will also be used for HTTPS
  // connections with the OAuth server.