public async Task Contains_CallsCleaner() { // Arrange ICleaner cleaner = Substitute.For <ICleaner>(); IStorage storage = await CreateStorageWithSchedulerAndWait(cleaner); // Act storage.Contains(""); // Assert cleaner.Received(1).Clear(Arg.Any <PriorityQueue <ExpiringKey> >(), Arg.Any <Dictionary <Key, Element> >()); }