These examples/tests are for when the SWIG generated wrapper module is split

between two packages. Specifically the pure python part is part of a package

and the C/C++ part is not in any package at all. Historically SWIG has

supported this sort of thing.

From SWIG 4.0.0 onwards, split modules are not supported by default.

The %module directive needs to be customised with the moduleimport attribute

in order to import a global C/C++ module.

vanilla # "plane Jane" module both halves in pkg1

vanilla_split # python 1/2 in pkg1 C 1/2 in global namespace