如何使用OAuth 2.0授权谷歌在Ruby中的预测性API ?

I am trying to simply send a request to google's hosted model sample.sentiment. I cannot figure out how to authorize with Oauth 2.0 via google, and I am getting endless amounts of hours. If you could provide me the code to this is would be helpful. Here is what I am working off of.I am trying to simply send a request to google'