docs: function placeForTarget( targetOrPlaceId, place = activePlace ) {
        let placeId = place ? place.targets[ targetOrPlaceId ] : null;
        if( placeId == null ) {
           placeId = targetOrPlaceId;
        }
        assert.state(
           placeId in availablePlaces,
           `Unknown target or place "${targetOrPlaceId}". Current place: "${place.id}"`
        );
        return availablePlaces[ placeId ];
     }