What does this implement/fix? Explain your changes.

Fixes the demo scripts (@burque505, FYI)

Does this close any currently open issues?

...

Any other comments?

@lostmsu Do you remember when the behaviour of the constructor changed? Apparently, we now require an explicit call to __init__ for a class that derives from a .NET class, it seems like this used to be handled in __new__.

Checklist

Check all those that are applicable and complete.

• Make sure to include one or more tests for your change
• If an enhancement PR, please create docs and at best an example
• Ensure you have signed the .NET Foundation CLA
• Add yourself to AUTHORS
• Updated the CHANGELOG