virtual void AddOptionalPropertySet ( [UInteractiveToolPropertySet](API\Runtime\InteractiveToolsFramework\UInteractiveToolPropertySet) * PropSet, [TUniqueFunction](API\Runtime\Core\Templates\TUniqueFunction)< bool()> VisibilityFunc, [TUniqueFunction](API\Runtime\Core\Templates\TUniqueFunction)< void()> OnModifiedFunc, bool bChangeInvalidatesResult )