"undefined" class in ZoomableGroup

[lucasvazq]

Description

If you create a ZoomableGroup and don't add the className attribute, it will be created with the following classes: rsm-zoomable-group undefined.

Example

Search undefined in https://www.react-simple-maps.io/docs/zoomable-group/

Importance

This can lead to real problems if someone has a class called undefined, something dangerous in js applications by the way, but not that common.

How to temporarily avoid this problem

To avoid this problem, just create a ZoomableGroup and pass an empty string in the className attr.