code: func FetchCertificatesFromLUCIService(c context.Context, serviceURL string) (*PublicCertificates, error) {
  	return FetchCertificates(c, serviceURL+"/auth/api/v1/server/certificates")
  }
docs: // FetchCertificatesFromLUCIService is shortcut for FetchCertificates
  // that uses LUCI-specific endpoint.
  //
  // 'serviceURL' is root URL of the service (e.g. 'https://example.com').