public void CountSubSequent()
{
var subject = new ReplaySubject <int>();
subject.OnNext(0);
subject.OnNext(0);
subject.OnNext(1);
subject.OnNext(0);
var count = subject.CountSubsequent(i => i).SubscribeReplay();
var items = count.Test().Items;
items.Count.ShouldBe(2);
items[0].length.ShouldBe(2);
items[0].item.ShouldBe(0);
items[1].length.ShouldBe(1);
items[1].item.ShouldBe(1);
}