code: def check_access_token(self, openid=None, access_token=None):
          
          openid = openid or self.open_id
          access_token = access_token or self.access_token
          res = self._get(
              'sns/auth',
              params={
                  'access_token': access_token,
                  'openid': openid
              }
          )
          if res['errcode'] == 0:
              return True
          return False
docs: 检查 access_token 有效性
  
          :param openid: 可选，微信 openid，默认获取当前授权用户信息
          :param access_token: 可选，access_token，默认使用当前授权用户的 access_token
          :return: 有效返回 True，否则 False