It's a list, so this would be pointing to the latest one or top of the stack. So something based on that?

Although I don't see why you'd expose a commit. Isn't the point of a stash API to abstract away the fact that it's implemented as a hack on top of the reflog? Saying it's a `ReferenceWrapper` is a red herring IMO, as it gets bogged down in the fact that it needs a ref in order to have a reflog that won't be gc'd away. In any case, a stash entry isn't one commit but a pair, one representing the index and another the worktree. The message of the entry at the top of the stack is stored in the commit pointed to by `refs/stash` but it's in the reflog message anyway.