public ClientCredentialsClient()
        {
            var app = TokenClientIdentityServer.Create();

            _handler = new OwinHttpMessageHandler(app.Build());
            _client  = new HttpClient(_handler);
        }
        public UserInfoEndpointClient()
        {
            var app = TokenClientIdentityServer.Create();

            _handler = new OwinHttpMessageHandler(app.Build());
            _client  = new HttpClient(_handler);
        }