public static IAppBuilder UseClientCertificateAuthentication(this IAppBuilder appBuilder)
 {
     var options = new ClientCertificateAuthenticationOptions();
     return appBuilder.UseClientCertificateAuthentication(options);
 }
 public static IAppBuilder UseClientCertificateAuthentication(this IAppBuilder appBuilder, ClientCertificateAuthenticationOptions options)
 {
     return appBuilder.Use<ClientAuthenticationMiddleware>(options);
 }