code: def _set_cookies(self, cookies):
          
          cookie_dict = helpers.parse_cookies_str(cookies)
          self.s.cookies.update(cookie_dict)
docs: 设置雪球 cookies，代码来自于
          https://github.com/shidenggui/easytrader/issues/269
          :param cookies: 雪球 cookies
          :type cookies: str