Sequence of AsyncHandle should be able to be resolved asynchronously

[FrozenCow]

At the moment when you have a Sequence with AsyncHandle-items, it is handled just like that. However it would be nice if these items could be resolved to their actual values.

I wasn't sure how to do this with the existing API. Is this already possible? If not, what would be the best approach to tackling this? Should I create a custom AsyncSequence with its own Iterator?

Just as a bit of background: I have a list of URLs and I want to map those to HTML. This can only be done with an async operation. I couldn't figure out how to do this with Lazy.js, even though Lazy.js comes closest in total functionality I'd like.