public void Initialize() { _resourceReleaser = new ResourceReleaserImpl <int>(_ => { }); _dataSubscriber = new MockDataSubscriber <IList <CloseableReference <int> > >(); _settableDataSource1 = SettableDataSource <int> .Create <int>(); _settableDataSource2 = SettableDataSource <int> .Create <int>(); _listDataSource = ListDataSource <int> .Create(_settableDataSource1, _settableDataSource2); _ref1 = CloseableReference <int> .of(1, _resourceReleaser); _ref2 = CloseableReference <int> .of(2, _resourceReleaser); _runtimeException = new Exception(); _listDataSource.Subscribe(_dataSubscriber, CallerThreadExecutor.Instance); }