MeshMapUsage Normal issue

Hi, 
I have a TypeError with 

usage = substance_painter.textureset.MeshMapUsage.Normal
or
usage = substance_painter.textureset.MeshMapUsage.Curvature

 when used in 

my_texture_set.get_mesh_map_resource(usage)

works well on other meshmapusage such as Position, Thickness, AO and others.

 like:

usage = substance_painter.textureset.MeshMapUsage.AO

or

usage = substance_painter.textureset.MeshMapUsage.Thickness

Not sure what is happenning there

[Python] get_mesh_map_resource(): incompatible function arguments. The following argument types are supported:
1. (texture_set_id: int, usage: _substance_painter.textureset.MeshMapUsage) -> str

Invoked with: 31947, Resource(handle=<_substance_painter.resource.ResourceHandle object at 0x0000028218B356B0>)