With double rewrite, imitate will use private API.

I suspect we'll move to a mode where every single layer of an imitation
is mapped to a Double value, regardless of whether `fake` is a clone or
a test double function. it'll allow us to say quite a lot more when 
td.explain()'ing. 

However, that's not something we have to solve right away (pre-relaunch)

Author: searls

src/imitate/create-imitation.js

@@ -10,6 +10,7 @@ export default (original, names) => {
     if (isGenerator(original)) {
       return original
     } else {
+      // TODO: this will become src/function/create and include parent reference instead of name joining here
       return tdFunction(names.join('') || '(anonymous function)')
     }
   } else {