mio extra timers don't fire

mio-timer-test.rs

use std::time::Duration;
use mio::{Events, Ready, Poll, PollOpt, Token};
use mio_extras::channel;
use mio_extras::timer::Timer;

fn main() {
    const CHANNEL: Token = Token(0);
    let poll = Poll::new().unwrap();
    let (tx, rx) = channel::channel::<u32>();
    let mut events = Events::with_capacity(1024);
    let mut tok = 1;

    tx.send(1).unwrap();
    poll.register(&rx, CHANNEL, Ready::readable(), PollOpt::edge()).unwrap();
    loop {
        poll.poll(&mut events, None).expect("poll.poll failed");
        for event in events.iter() {
            println!("event");
            if event.token() == CHANNEL {
            	let _t: u32 = rx.try_recv().unwrap();
                let when = Duration::from_secs(2);
                let mut timer = Timer::default();
                let timer_token = Token(tok);
                println!("channel tok: {} when: {:?}", tok, when);
                timer.set_timeout(when, tok);
                tok += 1;
                poll.register(&timer, timer_token, Ready::readable(), PollOpt::edge()).unwrap();
            } else {
                println!("timer: {:?}", event)
            }
        }
    }
}