FORCEINLINE[TSelectionSetIteratorState](API\Editor\SequencerCore\MVVM\Selection\TSelectionSetIteratorState)< [TWeakViewModelPtr](API\Editor\SequencerCore\TWeakViewModelPtr)< [IOutlinerExtension](API\Editor\SequencerCore\MVVM\Extensions\IOutlinerExtension) > > begin() const