string(239) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%8F%82%E8%80%83%E6%96%87%E7%8C%AE%E6%80%8E%E4%B9%88%E5%BC%95%E7%94%A8%E4%B9%A6%E7%B1%8D => Received HTTP code 403 from proxy after CONNECT"
参考文献怎么引用书籍
