I've been given a metal straw at a restaurant. My immediate thought: how do I know this is clean on the inside? I can't see in there, it could be full of mold.

I've been given a metal straw at a restaurant. My immediate thought: how do I know this is clean on the inside? I can't see in there, it could be full of mold. I just drank from the glass instead, because I'm an able-bodied adult.