def get_hosting_device_plugging_driver(self, context, id):
        """Returns  plugging driver for hosting device template with <id>."""
        if id is None:
            return
        try:
            return self._plugging_drivers[id]
        except KeyError:
            try:
                template = self._get_hosting_device_template(context, id)
                self._plugging_drivers[id] = importutils.import_object(
                    template['plugging_driver'])
            except (ImportError, TypeError, n_exc.NeutronException):
                LOG.exception("Error loading plugging driver for hosting "
                              "device template %s", id)
            return self._plugging_drivers.get(id)