Richard Machielse

@kimroen can this get some attention? Would like to get rid of the deprecation warning.

I think the biggest issue is that the routes tab crashes completely with engines (see ember-engines/ember-engines#385) because the route handler is being resolved asynchronously. Would a pr be desired?

@DevS1993 did you end up submitting a PR? We are running into the same issue. If not, can I submit a PR instead @pablobm?

@nathanhammond @trentmwillis are you still interested in having something like this in ember-engines? This is exactly what we need for our application. Do you have any idea of the complexity...

Maybe it would be even cleaner to support `polymorphic: true`, just the way it works with relationships. That way you would get: ```ruby VehicleSerializer.new([car, bus], polymorphic: true) ```

@pablobm what do you think? Does this have a chance of getting merged?

@pablobm would it be okay if I adapt the existing examples to use a plural namespace, like `admin/libraries/books`?

@pablobm example added!

Thank you!

@mike-north @rwjblue anyone who can merge/release this trivial change?