protected function indexEdge(array $entity): void
    {
        //$tail_id = $entity[]
        $entity["attributes"]["udid"] = $entity["id"];
        $cq = sprintf("MATCH(t {udid: {tail}}), (h {udid: {head}}) MERGE (t)-[e:%s {udid: {udid}}]->(h) SET e = {data}", $entity["label"]);
        $result = $this->client->run($cq, [
            "tail" => $entity["tail"],
            "head" => $entity["head"],
            "udid" => $entity["id"],
            "data" => $entity["attributes"]
        ]);
    }