JS middleware: object provided to `TykJS.TykMiddleware.NewMiddleware` constructor

The JS middleware doc mentions creating a middleware instance like so:

var sampleMiddleware = new TykJS.TykMiddleware.NewMiddleware({});

I’m curious what the empty JS object ({}) is that is provided to the NewMiddleware constructor. Could I provide custom properties to this object, or would be preferable to have a different variable in the file that would be referenced from within the NewProcessRequest function?