string(240) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E9%9B%86%E7%BA%BF%E5%99%A8%E6%9C%89%E4%BB%80%E4%B9%88%E5%8A%9F%E8%83%BD => Failed to connect to 101.89.117.144 port 38017: Connection refused"
集线器有什么功能
