public void ThrowsWhenBatchUpdateThrows()
{
var observables = createObservables();
dataSource.BatchUpdate(Arg.Any <IEnumerable <IThreadSafeTestModel> >()).Returns(
Observable.Throw <IEnumerable <IConflictResolutionResult <IThreadSafeTestModel> > >(new TestException()));
Action startingState = () => state.Start(observables).SingleAsync().Wait();
startingState.Should().Throw <TestException>();
}