private boolean compareAndSet() {
        return this.active.compareAndSet(true, false);
    }
Check if the cache is still active and has not shut down.

@return {@code true} if the cache is active, otherwise return {@code false}.
@since 5.2
httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/ManagedHttpCacheStorage.java