public function addLog($requestParam, $url, $requestRes) {
    $log_path = APP_PATH . 'log/'; 
    $log_file = date("Y-m-d") . '.log';
    if (!is_dir($log_path)) {
        mkdir($log_path, 0777, true);
    }

    $log_data = 'request_time: ' . date('Y-m-d H:i:s') . PHP_EOL . 'request_url: ' . $url . PHP_EOL . 'request_param: ' . json_encode($requestParam, JSON_UNESCAPED_SLASHES) . PHP_EOL . 'request_res: ' . $requestRes . PHP_EOL .PHP_EOL;
    file_put_contents($log_path . $log_file, $log_data, FILE_APPEND);
}