facebooker2

With Rails, how to convert code which used Facebooker to using Facebooker2?

There is code to use Facebooker gem (which uses the old Facebook REST API). Does someone have experience how to convert those code to using Facebooker2, which uses the new Facebook Graph API? For example, Facebooker has Facebooker::Session and Facebooker::User and they are both gone in Facebooker2. I can't find too much docs on the tw...