void remove() {
            HashedWheelBucket bucket = this.bucket;
            if (bucket != null) {
                bucket.remove(this);
            } else {
                timer.pendingTimeouts.decrementAndGet();
            }
        }
Calculate goal nanoTime from startTime and current tick number,
then wait until that goal has been reached.

@return Long.MIN_VALUE if received a shutdown request,
current time otherwise (with Long.MIN_VALUE changed by +1)
jraft-core/src/main/java/com/alipay/sofa/jraft/util/timer/HashedWheelTimer.java