Can I inject Mock Ember Mixins when unit testing?

I'm currently writing unit tests for an ember controller.

The target controller has a couple Mixins as dependencies.

export default Ember.Controller.extend (MixinA, MixinB, MixinC, { /* ... */ });

As my intention to write unit tests, not integration tests, I don't want to concern myself with what these Mixins contain or are doing, but rather mock them out (e.g. using ember-sinon).

Is it possible to mock them?

How can I inject the mocks into my test controller?