virtual void ExtendLeftAlignedToolbarSlots ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SHorizontalBox](API\Runtime\SlateCore\Widgets\SHorizontalBox) > MainBoxPtr, [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SViewportToolBar](API\Editor\UnrealEd\SViewportToolBar) > ParentToolBarPtr ) const