Integrating mutators with backbone.relational

I've faced the following issue while trying to integrate Backbone.Mutators with Backbone.Relational which is used to build client side relations and helps to serialize/deserialize data into corresponding json/models.

For example lets assume we have a model (in coffeescript)

``` coffeescript
@ClientApp.module "Entities", (Entities, App, Backbone, Marionette, $, _) ->
class Entities.Store extends Entities.RelationalModel

defaults:
location: -> new Entities.Location()

mutators:
store_name: ->
@get("location")?.get("name")
```

What I have now is trying to access related model in mutator will result in an error. That is because backbone.relational haven't yet converted the model's sub-object into an instance of underlying model at the time backbone.mutators serialize data and hence `@get('location')` will return a json object instead of Entities.Location instance.
I've applied a quick fix by changing the library to save `get` and `set` methods from Backbone.RelationalModel.

``` javascript
var Mutator = function () {},
oldGet = Backbone.RelationalModel.prototype.get,
oldSet = Backbone.RelationalModel.prototype.set,
oldToJson = Backbone.RelationalModel.prototype.toJSON;

...

_.extend(Backbone.RelationalModel.prototype, Mutator.prototype);
```

However i do not really like this fix as far as i will have to apply it every time Backbone.Mutators is updated. Perhaps someone has a more consistent solution? Also please let me know if you need any additional info.