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    use super::assert_stream;
    use core::marker;
    use core::pin::Pin;
    use futures_core::stream::{FusedStream, Stream};
    use futures_core::task::{Context, Poll};

    /// Stream for the [`pending()`] function.
    #[derive(Debug)]
    #[must_use = "streams do nothing unless polled"]
    pub struct Pending<T> {
        _data: marker::PhantomData<T>,
    }

    /// Creates a stream which never returns any elements.
    ///
    /// The returned stream will always return `Pending` when polled.
    pub fn pending<T>() -> Pending<T> {
        assert_stream::<T, _>(Pending { _data: marker::PhantomData })
    }

    impl<T> Unpin for Pending<T> {}

    impl<T> FusedStream for Pending<T> {
        fn is_terminated(&self) -> bool {
            true
        }
    }

    impl<T> Stream for Pending<T> {
        type Item = T;

        fn poll_next(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Option<Self::Item>> {
            Poll::Pending
        }

        fn size_hint(&self) -> (usize, Option<usize>) {
            (0, Some(0))
        }
    }

    impl<T> Clone for Pending<T> {
        fn clone(&self) -> Self {
            pending()
        }
    }