I tried to add tests for the isInitialized method of a realtime model but the method appears not to be defined.
Method documentation: https://developers.google.com/drive/realtime/reference/gapi.drive.realtime.Model#gapi.drive.realtime.Model.prototype.isInitialized
model.getRoot().set('key', 'val'); // works
model.isInitialized(); // method not found error