Ground:db to make collection offline accessible

How do I ground (using ground:db) a collection to get offline access?

I’m trying this, but it doesn’t work at all… I think there is a problem with export, as it doesn’t seems to be correct?!

/imports/api/cars/collection.js

export default Cars = new Mongo.Collection('cars');

if (Meteor.isCordova)
	Ground.Collection(Cars);

Cars.deny({
	insert() { return true; },
	update() { return true; },
	remove() { return true; }
});

/imports/ui/cars/list.js

import Cars from '/imports/api/cars/collection.js';

Template.example.helpers({

	list() {
		return Cars.find({});
	}
});