Fix expand in _ObservableImmutableListView
Fix expand in _ObservableImmutableListView

ronlobo/streamy-dart,srawlins/streamy-dart,google/streamy-dart,ronlobo/streamy-dart,srawlins/streamy-dart,google/streamy-dart,google/streamy-dart,srawlins/streamy-dart,google/streamy-dart,ronlobo/streamy-dart,ronlobo/streamy-dart,srawlins/streamy-dart