def collection
      return Collection.find(source_id) if Collection.exists?(source_id)
      raise ActiveFedora::ObjectNotFoundError
    rescue ActiveFedora::ActiveFedoraError # TODO: remove the rescue when active_fedora issue #1276 is fixed
      raise ActiveFedora::ObjectNotFoundError
    end
def collection
      return Collection.find(source_id) if Collection.exists?(source_id)
      raise ActiveFedora::ObjectNotFoundError
    rescue ActiveFedora::ActiveFedoraError # TODO: remove the rescue when active_fedora issue #1276 is fixed
      raise ActiveFedora::ObjectNotFoundError
    end
A bit of an analogue for a `belongs_to :collection` as it crosses from Fedora to the DB
 @return [Collection]
 @raise [ActiveFedora::ObjectNotFoundError] when the we cannot find the Collection