I agree that modules.express way is a bit awkward.

From what I could tell yesterday (and I may have misinterpreted something), the semantics of JS prevent what @n1k0 suggests from working: at compile time, the contents of the empty variable _wss get copied to module.exports._wss, rather than module.exports._wss being made an alias for the local var.   vars seem to be different than functions in this respect.