The original plan here was to allow for stuff like impl setup methods which are not part of the exposed interface. Not sure if we still need that for anything...

#58 (comment) has some discussion of why this might be a good idea, although it's not concrete enough for me to say that we definitely want to keep the current form, so I'll leave this open for now.

I believe that the following:

export default class SomeInterface {
	//
}

is better than:

class SomeInterface {
	//
}
export { SomeInterface as implementation };

I’m doing this in #141.