public static function getSignContent(array $data, $verify = false): string
    {
        $data = self::encoding($data, $data['charset'] ?? 'gb2312', 'utf-8');

        ksort($data);

        $stringToBeSigned = '';
        foreach ($data as $k => $v) {
            if ($verify && $k != 'sign' && $k != 'sign_type') {
                $stringToBeSigned .= $k.'='.$v.'&';
            }
            if (!$verify && $v !== '' && !is_null($v) && $k != 'sign' && '@' != substr($v, 0, 1)) {
                $stringToBeSigned .= $k.'='.$v.'&';
            }
        }

        Log::debug('Alipay Generate Sign Content Before Trim', [$data, $stringToBeSigned]);

        return trim($stringToBeSigned, '&');
    }