topic = XML.string_from_xpath(~s{//Link[@rel="http://schemas.google.com/g/2010#updates-from"]/@href}, doc)
subject = XML.string_from_xpath("//Subject", doc)
salmon = XML.string_from_xpath(~s{//Link[@rel="salmon"]/@href}, doc)
topic = XML.string_from_xpath(~s{//Link[@rel="http://schemas.google.com/g/2010#updates-from"]/@href}, doc)
subject = XML.string_from_xpath("//Subject", doc)
salmon = XML.string_from_xpath(~s{//Link[@rel="salmon"]/@href}, doc)