How can I use the AppEngine::Datastore api's in JRuby like in python?

Question

So in python I would do something like this:

from google.appengine.ext import db

class Thing(db.Model):
    name = db.StringProperty()

In ruby how would I do this using the AppEngine::Datastore libs?

The reason I ask this is because I'm hitting some hard walls using the Datamapper adapter and so I plan on just using the AppEngine api's directly, but there isn't much documentation on how to do this.