i think you might be able to accomplish this by just doing `url_helpers.discussion_path(@notification.eventable.discussion, proposal: @notification.eventable.motion_id)`.

Also, wherever you can it's good to refer to the id directly instead of instantiating a new object just to get an id (i.e. `eventable.motion_id` is preferable to `eventable.motion.id`). It's easier to test and better for performance (why instantiate an object if you don't need to?).