public void A_TakeWhile_must_take_while_predicate_is_true()
{
this.AssertAllStagesStopped(() =>
{
Source.From(Enumerable.Range(1, 4))
.TakeWhile(i => i < 3)
.RunWith(this.SinkProbe<int>(), Materializer)
.Request(3)
.ExpectNext(1,2)
.ExpectComplete();
}, Materializer);
}