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    use crate::stream::StreamExt;
    use core::pin::Pin;
    use futures_core::future::{FusedFuture, Future};
    use futures_core::stream::{FusedStream, Stream};
    use futures_core::task::{Context, Poll};

    /// Future for the [`next`](super::StreamExt::next) method.
    #[derive(Debug)]
    #[must_use = "futures do nothing unless you `.await` or poll them"]
    pub struct Next<'a, St: ?Sized> {
        stream: &'a mut St,
    }

    impl<St: ?Sized + Unpin> Unpin for Next<'_, St> {}

    impl<'a, St: ?Sized + Stream + Unpin> Next<'a, St> {
        pub(super) fn new(stream: &'a mut St) -> Self {
            Self { stream }
        }
    }

    impl<St: ?Sized + FusedStream + Unpin> FusedFuture for Next<'_, St> {
        fn is_terminated(&self) -> bool {
            self.stream.is_terminated()
        }
    }

    impl<St: ?Sized + Stream + Unpin> Future for Next<'_, St> {
        type Output = Option<St::Item>;

        fn poll(
            mut self: Pin<&mut Self>,
            cx: &mut Context<'_>,
        ) -> Poll<Self::Output> {
            self.stream.poll_next_unpin(cx)
        }
    }