The code below is valid for 'futures' 0.1
let future = ... // some future
let timeout = ... // future with timeout
let app = future.select(tiemout); // it was available in 'futures' 0.1
ThreadPool::new()
.expect("Failed to create threadpool")
.run(app)
.unwrap();
How it can be refactored for using with 'futures-preview' 0.3 ?