`fdb_future_block_until_ready` on multiple futures

Is there some reason why we don’t have an API in the C bindings that allows us to block on multiple futures at the same time?

As I was thinking about layer development using my rust bindings, I realized there can be scenarios where I might want to sleep the thread and wake up when any of the FDB futures that I am interested in resolves.

Is using fdb_future_set_callback only way to handle this?