How to get widget "persona preview viewport" to add to the"Custom Asset Editor"

How to get widget “persona preview viewport” to add to the"Custom Asset Editor"

in .h:

TSharedPtr<class ???> PreviewScene;
TSharedRef<SDockTab> SpawnTab_Preview(const FSpawnTabArgs& Args);

what class does the preview viewport skeleton mesh?
in .cpp

void FMyObjEditor::InitMyObjEditor(const EToolkitMode::Type Mode, const TSharedPtr<class IToolkitHost>& InitToolkitHost, class UMyObj* Asset)
{
    	FPersonaModule& PersonaModule = FModuleManager::LoadModuleChecked<FPersonaModule>("Persona");
	PersonaToolkit = PersonaModule.CreatePersonaToolkit(Asset->Pose);
	PersonaToolkit->GetPreviewScene()->SetDefaultAnimationMode(EPreviewSceneDefaultAnimationMode::Animation);
	FSkeletonTreeArgs SkeletonTreeArgs;
	SkeletonTreeArgs.PreviewScene = PersonaToolkit->GetPreviewScene();
	SkeletonTreeArgs.ContextName = GetToolkitFName();

	ISkeletonEditorModule& SkeletonEditorModule = FModuleManager::GetModuleChecked<ISkeletonEditorModule>("SkeletonEditor");
	SkeletonTree = SkeletonEditorModule.CreateSkeletonTree(PersonaToolkit->GetSkeleton(), SkeletonTreeArgs);
	PersonaToolkit->GetPreviewScene()->SetDefaultAnimationMode(EPreviewSceneDefaultAnimationMode::ReferencePose);

PreviewScene = ???;

const TSharedRef<FTabManager::FLayout> StandaloneDefaultLayout = FTabManager::NewLayout("CustomEditor_Layout_2")
		->AddArea(
...

How to get this class from PersonaModule

and how to spawn preview widget in

TSharedRef<SDockTab> FMyObjEditor::ISpawnTab_Preview(const FSpawnTabArgs& Args)
{

}

?