public static ConnTimer from(Channel chan) {
        Objects.requireNonNull(chan);
        ConnTimer timer = chan.attr(CONN_TIMER).get();
        if (timer != null) {
            return timer;
        }
        if (chan.parent() != null && (timer = chan.parent().attr(CONN_TIMER).get()) != null) {
            return timer;
        }
        throw new IllegalStateException("no timer on channel");
    }
A timer for connection stats.  Not thread-safe.
zuul-core/src/main/java/com/netflix/zuul/monitoring/ConnTimer.java