1. async fn cancel_task() -> tokio::io::Result<()> {
    2.     let handle = tokio::spawn(async {
    3.         for i in 0..10 {
    4.             tokio::time::sleep(std::time::Duration::from_secs(1)).await;
    5.             println!("Ping! {}", i);
    6.         }
    7.     });
    9.     tokio::time::sleep(std::time::Duration::from_secs(5)).await;
    10.     handle.abort();
    11.     match handle.await {
    12.         Ok(_) => Ok(()),
    13.         Err(e) if e.is_cancelled() => Ok(()),
    14.         Err(e) => Err(e),
    15.     }?;
    16.     Ok(())
    17. }