public void ServiceUnavailable()
{
var controller = new DummyController
{
Configuration = new HttpConfiguration(),
Request = new HttpRequestMessage()
};
var retryAfter = TimeSpan.FromSeconds(5);
var result = controller.ServiceUnavailable(retryAfter);
result.Should().BeOfType <ServiceUnavailableResult>().And.Should().NotBeNull("because a result should have been generated");
result.Request.Should().NotBeNull("Retry-After", "because the response should specify the Retry-After.");
result.RetryAfter.Should().Be(retryAfter, "because the duration should match the provided TimeSpan");
}