How are attached properties useful in LINQ?

I got this question during an interview in the past and never really dug into in, but I've put some thought into it lately and I can't come up with a good answer. When I think of attached properties my mind goes straight to UI related concepts - what benefits could be had in using attached properties with LINQ? I'm starting to think the answer is "they're not" 开发者_运维问答unless I find out otherwise!

Linq and attached properties are not related. I think this question is asked to confuse you.