var server = CreateTestServer();

            var httpHandler = server.CreateHandler();
            var client = new HttpClient(httpHandler);
            client.BaseAddress = new Uri("https://idp");

            var doc = await client.GetDiscoveryDocumentAsync();

            //resource owner password
            var reqPassToken = new PasswordTokenRequest()
            {
                Address = doc.TokenEndpoint,
                UserName = "test",
                Password = "test",
                ClientId = "client1",
                ClientSecret = "secret"
            };
            var roToken = await client.RequestPasswordTokenAsync(reqPassToken);

            var reqIntroToken = new TokenIntrospectionRequest()
            {
                Address = doc.IntrospectionEndpoint,
                ClientId = "api1",
                ClientSecret = "secret",
                Token = roToken.AccessToken
            };

            foreach (var _ in Enumerable.Range(1, 10))
                (await client.IntrospectTokenAsync(reqIntroToken)).IsActive.Should().BeTrue();

            logger.AccessCount["Cache hit for 1"].Should().Equals(10);