@Override
    public Set<Entry<K, V>> entrySet() {
        return cache.asMap().entrySet();
    }
The differences between this class and {@link MemorySafeLRUMap}
is that this class is thread safe, and it use WindowTinyLFU algorithm
provided by caffeine which is better than LRU algorithm.
shenyu-common/src/main/java/org/apache/shenyu/common/cache/MemorySafeWindowTinyLFUMap.java