ControllerMixin `actions` object isn't recognized in `send`

Not sure if this is a bug or intended behavior. I've created an Ember.Object that includes the ControllerMixin. This gives it the send function, which should be able to find functions within the actions object. It cannot do so, however. Instead, it looks in the private _actions object, so that if I put my actions inside of _actions, everything works. Is this intended? If so, why?