public void Should_call_the_method_only_once()
{
var tracker = new Tracker(3);
IRetryPolicy retryPolicy = Retry.Filter <InvalidOperationException>(x => false).Immediate(5);
Task task = ComposerFactory.Compose(composer => composer.Retry(retryPolicy, x => x.Execute(tracker.FaultingMethod)));
Assert.Throws <InvalidOperationException>(async() => await task);
Assert.AreEqual(1, tracker.CallCount);
}