private void start() {
        int state = WORKER_STATE_UPDATER.get(this);
        if (state == 0) {
            if (WORKER_STATE_UPDATER.compareAndSet(this, 0, 1)) {
                workerThread.start();
            }
        }
    }
Instantiates a new System timer.

@param executorName the executor name
@param tickMs       the tick ms
@param wheelSize    the wheel size
@param startMs      the start ms
shenyu-common/src/main/java/org/apache/shenyu/common/timer/HierarchicalWheelTimer.java