You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: yield_now.rs
    path of file: ./repos/tokio/tokio/src/task
    
    the code of the file until where you have to start completion: use crate::runtime::context;

use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};

/// Yields execution back to the Tokio runtime.
///
/// A t
    
pub async fn yield_now() {
    /// Yield implementation
    struct YieldNow {
        yielded: bool,
    }

    impl Future for YieldNow {
        type Output = ();

        fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
            ready!(crate::trace::trace_leaf(cx));

            if self.yielded {
                return Poll::Ready(());
            }

            self.yielded = true;

            context::defer(cx.waker());

            Poll::Pending
        }
    }

    YieldNow { yielded: false }.await;
}