Code review comment for lp:~themue/pyjuju/go-state-remove-relation

https://codereview.appspot.com/6250076/diff/1/state/relation.go
File state/relation.go (right):

https://codereview.appspot.com/6250076/diff/1/state/relation.go#newcode52
state/relation.go:52: relationKey() string
Why is this being turned into an interface that has a single
implementation and no chance of ever being implemented by anyone outside
of this package?

I've read the description of the CL, but it still makes no sense to me.

https://codereview.appspot.com/6250076/