Web scraping Rvest刮取结果为空列表

我有一个简单的问题：我试图从一个网页上获取赔率，但结果是一个空白列表

library(rvest)
url<- 'http://www.betexplorer.com/soccer/italy/serie-a-2016-2017/'
html <- read_html(url)
odds <- html_nodes(html, '.table-matches__odds , .colored span')
odds <- html_text(odds)

库（rvest）
网址
library(rvest)
url<- 'http://www.betexplorer.com/soccer/italy/serie-a-2016-2017/'
html <- read_html(url)
odds <- html_nodes(html, xpath='//*[contains(concat( " ", @class, " " ),   concat( " ", "table-matches__odds", " " ))]')
odds <- html_text(odds)