Dealing with single resources

How would one use Restangular to query single document resources. They are not a collection, and they cannot have child objects. They are a single flat object.

I was thinking Restangular.one('resource'). But the docs seem to indicate that one always needs an id parameter. But these single resources have no such thing. There's no id to them, because there's is only one resource to the resource endpoint. (And there will always be only one resource to this resource endpoint)