Thanks for this example! As I was reading the post, I was thinking "cool, and feels like a thing people would expect, but does it have a real world usecase?".

Thanks for this example! As I was reading the post, I was thinking "cool, and feels like a thing people would expect, but does it have a real world usecase?". This feels like an actual real-world thing people might want to do where indeed you'd want to have a single NULL value.