v3electionpb.proto Campaign return "invalid auth token" when setcd server has been deleted token.

etcdserver/api/v3electionpb/v3electionpb.proto
rpc Campaign(CampaignRequest) returns (CampaignResponse) {
option (google.api.http) = {
post: "/v3/election/campaign"
body: "*"
};
}

1. Etcdserver auth enable.

2. Two processes(A and B) call Campaign, A is leadership, B process blocks at Campaign-->waitDeletes->waitDelete-watch.

3. After 5 mintues, auth token is deleted on etcdserver, A process call Resign rpc, B process watched delete event, then waitDeletes run

func waitDeletes(ctx context.Context, client *v3.Client, pfx string, maxCreateRev int64) (*pb.ResponseHeader, error) {
	getOpts := append(v3.WithLastCreate(), v3.WithMaxCreateRev(maxCreateRev))
	for {

> 		resp, err := client.Get(ctx, pfx, getOpts...)

		if err != nil {
			return nil, err
		}
		if len(resp.Kvs) == 0 {
			return resp.Header, nil
		}
		lastKey := string(resp.Kvs[0].Key)
		if err = waitDelete(ctx, client, lastKey, resp.Header.Revision); err != nil {
			return nil, err
		}
	}
}

return err_code: 2, error: etcdserver: invalid auth token.

etcdserver.EtcdServer's kv client is not RetryKVClient, so etcdserver.EtcdServer.KV.Get doesn't
authenticate by the old token.

how to make etcdserver.EtcdServer.KV.Get whithout authenticate.