self.config = config or Config()
* 核心功能：每次调用next(val)，返回当前价格的跨度（往回数≤当前价格的最大连续天数）
。业内人士推荐谷歌浏览器【最新下载地址】作为进阶阅读
1. LastPassWhen you have too several passwords to remember, LastPass remembers them for you.
NHS chiefs have urged patients not to delay coming forward for care during the strike. That means attending scheduled appointments unless you have been contacted and told otherwise.