Example code using IncumbentUpdater

Hello,

I've searched through the documentation and found that it is possible to receive updates when a new feasible solution is found with [IncumbentUpdater](https://python-mip.readthedocs.io/en/latest/classes.html#incumbentupdater).

However I am really struggling to understand how this works.
I've also searched around for example code but was not able to find anything.

Would it be possible to provide a very simple example of how the IncumbentUpdater should be used?

Thanks in advance!