def METHOD_NAME(self, subnet_id):
    """Delete data from etcd for a subnet that is no longer wanted."""
    LOG.info("Deleting subnet %s", subnet_id)
    # Delete the etcd key for this subnet.
    key = datamodel_v2.key_for_subnet(subnet_id, self.region_string)
    if not self.delete_from_etcd(key):
        # Already gone, treat as success.
        LOG.debug("Key %s, which we were deleting, disappeared", key)