static void TestInternal_GoogleCerts()
        {
            var certs = Google.GetCertificatesByThumbprint(@"https://www.googleapis.com/oauth2/v1/certs");

            Debug.Assert(certs.Count > 0);
            Console.WriteLine(nameof(TestInternal_GoogleCerts));
            foreach (var cert in certs)
            {
                Console.WriteLine("\t{0}\t\t{1}", cert.Key, cert.Value.SubjectName.Name);
            }
            //Console.WriteLine();
        }