#vulnerable code 
                                @Override
    public void addLeaderStateListener(final long regionId, final LeaderStateListener listener) {
        checkState();
        if (this.storeEngine == null) {
            throw new IllegalStateException("current node do not have store engine");
        }
        final RegionEngine regionEngine = this.storeEngine.getRegionEngine(regionId);
        if (regionEngine == null) {
            throw new IllegalStateException("current node do not have this region engine[" + regionId + "]");
        }
        regionEngine.getFsm().addLeaderStateListener(listener);
    } 
                            #location 7 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                @Override
    public void addLeaderStateListener(final long regionId, final LeaderStateListener listener) {
        addStateListener(regionId, listener);
    }