How to use the rhino3dm.MeshType function in rhino3dm

if attr.MaterialIndex != -1:
            matname = material_name(model.Materials[attr.MaterialIndex])

        layeruuid = rhinolayer.Id
        rhinomatname = rhinolayer.Name + "+" + str(layeruuid)
        if matname:
            rhinomat = materials[matname]
        else:
            rhinomat = materials[rhinomatname]
        layer = layerids[str(layeruuid)][1]

        # concatenate all meshes from all (brep) faces,
        # adjust vertex indices for faces accordingly
        # first get all render meshes
        if og.ObjectType==r3d.ObjectType.Extrusion:
            msh = [og.GetMesh(r3d.MeshType.Any)]
        elif og.ObjectType==r3d.ObjectType.Mesh:
            msh = [og]
        elif og.ObjectType==r3d.ObjectType.Brep:
            msh = [og.Faces[f].GetMesh(r3d.MeshType.Any) for f in range(len(og.Faces)) if type(og.Faces[f])!=list]
        else:
            continue
        fidx=0
        faces = []
        vertices = []
        # now add all faces and vertices to the main lists
        for m in msh:
            if not m: continue
            faces.extend([list(map(lambda x: x + fidx, m.Faces[f])) for f in range(len(m.Faces))])
            fidx = fidx + len(m.Vertices)
            vertices.extend([(m.Vertices[v].X, m.Vertices[v].Y, m.Vertices[v].Z) for v in range(len(m.Vertices))])
        # done, now add object to blender