public void clearTimeouts(Set<Timeout> set) {
            for (;;) {
                HashedWheelTimeout timeout = pollTimeout();
                if (timeout == null) {
                    return;
                }
                if (timeout.isExpired() || timeout.isCancelled()) {
                    continue;
                }
                set.add(timeout);
            }
        }
Clear this bucket and return all not expired / cancelled {@link Timeout}s.
jraft-core/src/main/java/com/alipay/sofa/jraft/util/timer/HashedWheelTimer.java