FSlateMaterialBrush in 4.9?


I want to use FSlateMaterialBrush in UE4.9. but it seems like it is removed.
The API says it exists: FSlateMaterialBrush | Unreal Engine Documentation

but VS2013 says “FSlateMaterialBrush is undefined”.

does anyone know how to use FSlateMaterialBrush or a proper way to draw a Material on a Slate-SButton in C++?

this is a solution posted for 4.8 but not working in 4.9 due to undefined FSlateMaterialBrush: