const TopoDS_Shape& aShape = const_cast<GeomAPI_Face*>(this)->impl<TopoDS_Shape>();
Handle(Geom_Surface) aSurf = BRep_Tool::Surface(TopoDS::Face(aShape));
GeomLib_IsPlanarSurface isPlanar(aSurf);
const TopoDS_Shape& aShape = const_cast<GeomAPI_Face*>(this)->impl<TopoDS_Shape>();
Handle(Geom_Surface) aSurf = BRep_Tool::Surface(TopoDS::Face(aShape));
GeomLib_IsPlanarSurface isPlanar(aSurf);