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    use super::assert_future;
    use core::marker;
    use core::pin::Pin;
    use futures_core::future::{FusedFuture, Future};
    use futures_core::task::{Context, Poll};

    /// Future for the [`pending()`] function.
    #[derive(Debug)]
    #[must_use = "futures do nothing unless you `.await` or poll them"]
    pub struct Pending<T> {
        _data: marker::PhantomData<T>,
    }

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

    /// Creates a future which never resolves, representing a computation that never
    /// finishes.
    ///
    /// The returned future will forever return [`Poll::Pending`].
    ///
    /// # Examples
    ///
    /// ```ignore
    /// # futures::executor::block_on(async {
    /// use futures::future;
    ///
    /// let future = future::pending();
    /// let () = future.await;
    /// unreachable!();
    /// # });
    /// ```
    pub fn pending<T>() -> Pending<T> {
        assert_future::<T, _>(Pending {
            _data: marker::PhantomData,
        })
    }

    impl<T> Future for Pending<T> {
        type Output = T;

        fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<T> {
            Poll::Pending
        }
    }

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

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