[Feature Request] memoize_stampede with asyncio support

[yeus]

we can not use memoize_stampede on async functions right now. This feature would be appreciated. There is a feature request for moize: https://github.com/grantjenks/python-diskcache/pull/196/commits/3a6ae4bd282ca98bc967c4868da9f1a28aa1603c. But memoize_stampede seems to be a bit more involved than that example? would it be enough to simply replace the wrapper in it with an async def wrapper just like in the above pull request?