public function getMultiple($keys, $default = null)
    {
        $mgetResult = $this->call('mget', [$keys]);
        if ($mgetResult === false) {
            return $default;
        }
        $result = [];
        foreach ($mgetResult ?? [] as $key => $value) {
            $result[$keys[$key]] = $value;
        }

        return $result;
    }