[Question]How to call an async function in `ExecutionPlan::exec` method?

[JYInMyHeart]

I had customized some execution plan struct. In datafusion 7.1.0 the ExecutionPlan::exec method is async so I can directly call some async functions in it when I Implement some methods for ExecutionPlan. After upgrade datafusion to 9.0.0 the ExecutionPlan::exec becomes sync. So how can I call an async function in ExecutionPlan::exec method?
I have seen that SortExec in datafusion-core use futures::stream::once to wrap async calls. But futures::stream::once is not public for me. So how can I make it?

[tustvold]

futures::stream::once is part of the futures crate, and so if you add this to your Cargo.toml you should be able to make use of it

[JYInMyHeart]

futures::stream::once is part of the futures crate, and so if you add this to your Cargo.toml you should be able to make use of it

But I still don't know how to write the correct code even I add futures crate.

[JYInMyHeart]

@tustvold I fixed it. Thanks for your reply.