fn purge_finished(&mut self) {
        let now = Instant::now();

        for expired_finished in self.timeouts.purge(&now) {
            let _ = self.finished.remove(&expired_finished);
        }
    }
/// Retains only those finished entries which still haven't timed out.
Retains only those finished entries which still haven't timed out.
Retains only those finished entries which still haven ' t timed out .
fn purge_finished(&mut self) {
        let now = Instant::now();
        for expired_finished in self.timeouts.purge(&now) {
            let _ = self.finished.remove(&expired_finished);
        }
    }
fn purge_finished ( & mut self ) { let now = Instant :: now ( ) ; for expired_finished in self . timeouts . purge ( & now ) { let _ = self . finished . remove ( & expired_finished ) ; } }
Retains only those finished entries which still haven't timed out.
Retains only those finished entries which still haven ' t timed out .
&mut self
&mut self