Reschedule the work of an async function until some other time in the future
namespace HH\Asio; function later(): Awaitable<void>;
The common use case for this is if your async function actually has to wait
for some blocking call, you can tell other
Awaitables in the async
scheduler that they can work while this one waits for the blocking call to
finish (e.g., maybe in a polling situation or something).