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    use crate::io::AsyncWrite;

    use pin_project_lite::pin_project;
    use std::future::Future;
    use std::io;
    use std::marker::PhantomPinned;
    use std::pin::Pin;
    use std::task::{Context, Poll};

    pin_project! {
        /// A future used to shutdown an I/O object.
        ///
        /// Created by the [`AsyncWriteExt::shutdown`][shutdown] function.
        /// [shutdown]: crate::io::AsyncWriteExt::shutdown
        #[must_use = "futures do nothing unless you `.await` or poll them"]
        #[derive(Debug)]
        pub struct Shutdown<'a, A: ?Sized> {
            a: &'a mut A,
            // Make this future `!Unpin` for compatibility with async trait methods.
            #[pin]
            _pin: PhantomPinned,
        }
    }

    /// Creates a future which will shutdown an I/O object.
    pub(super) fn shutdown<A>(a: &mut A) -> Shutdown<'_, A>
    where
        A: AsyncWrite + Unpin + ?Sized,
    {
        Shutdown {
            a,
            _pin: PhantomPinned,
        }
    }

    impl<A> Future for Shutdown<'_, A>
    where
        A: AsyncWrite + Unpin + ?Sized,
    {
        type Output = io::Result<()>;

        fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
            let me = self.project();
            Pin::new(me.a).poll_shutdown(cx)
        }
    }