getNewSubContainerData
abstract fun getNewSubContainerData(panelContainerViewModel: PanelContainerViewModel<CD, VM, SD>): Collection<SD>
Determines if new panel sub-containers should be created, based on panelContainerViewModel.
If this method returns a non-empty collection, new panel sub-containers are created for each item in the returned collection.
Called whenever panelContainerViewModel is changed. PanelSubContainerViewModels can trigger a panelContainerViewModel change by changing a property that uses the PanelSubContainerViewModel.mutableExtraState delegate.