public void CleanupTest() { var time = T(TimeSpan.Zero); var target = new EventCounter(() => time, TimeSpan.FromMinutes(1)); target.Count("a"); target.Count("a"); target.Count("a"); time = T(TimeSpan.FromMinutes(5)); target.GetSnapshot() .Should().Contain(i => i.Key == "a"); target.Cleanup(); target.GetSnapshot() .Should().NotContain(i => i.Key == "a"); }