clone() without attributes not working

[wolframkriesing]

The docs say clone() takes optional attributes, from the source https://github.com/uxebu/bonsai/blob/master/src/runner/group.js#L45 it looks like it has to get an object, and it also fails if i call clone().
And if it only has one option, it feels better to have cloneWithAttributes() and clone() ... my 2 cents

current workaround is to use clone({attributes: true})