'Get device_owner for the specified router.'

def _get_device_owner(self, context, router=None):

    router_is_uuid = isinstance(router, six.string_types)
    if router_is_uuid:
        router = self._get_router(context, router)
    if is_distributed_router(router):
        return const.DEVICE_OWNER_DVR_INTERFACE
    return super(L3_NAT_with_dvr_db_mixin, self)._get_device_owner(context, router)
