pub trait Waker {
    // Required methods
    fn rx_wake(&self);
    fn tx_park(&self, w: Waker);
    fn close_channel(&self);
    fn is_closed(&self) -> bool;
}pub trait Waker {
    // Required methods
    fn rx_wake(&self);
    fn tx_park(&self, w: Waker);
    fn close_channel(&self);
    fn is_closed(&self) -> bool;
}