protected function error($errors = null, string $message = '')
    {

        if(!$errors) {
            $errors = ['Your request has not been validated by the system. Please check your request URL and parameters!'];
        }

        // make it array
        else if(!is_array($errors)) {
            $errors = [$errors];
        }

        return response()->json(['errors' => $errors], 400);
    }