public function track($cookie)
    {
        if ( ! $cookie) {
            $this->cookie()->queue(
                $this->cookie()->make($this->getConfig('cookie.name'), $cookie = (string) Uuid::uuid4())
            );
        }

        return $this->getModel()
                    ->newQuery()
                    ->firstOrCreate(['uuid' => $cookie])
                    ->getKey();
    }