generateScopedName as a function

I’m trying to use generateScopedName as a function which should be possible, but it resolves as `undefined`. F.ex;

``generateScopedName: (localName, resourcePath) => { return 'foo' }``

And then if I do `console.log(typeof options.generateScopedName)` in `requireCssModule` it becomes undefined. Strings works fine as the tests shows, but not functions.