@Override
public CompletableFuture<T> load() {
    final CompletableFuture<T> loadFuture = this.loadFuture;
    if (!loadFuture.isDone()) {
        // A load is in progress.
        return returnCacheOrFuture(cacheEntry, loadFuture);
    }

    final CacheEntry<T> cacheEntry = this.cacheEntry;
    final boolean isValid = isValid(cacheEntry);
    if (!isValid || needsRefresh(cacheEntry)) {
        final CompletableFuture<T> newFuture = new CompletableFuture<>();
        if (loadFutureUpdater.compareAndSet(this, loadFuture, newFuture)) {
            final T cache = cacheEntry != null ? cacheEntry.value : null;
            load(cache, newFuture);
            if (isValid) {
                logger.debug("Pre-fetching a new value. cache: {}, loader: {}", cache, loader);
                return UnmodifiableFuture.completedFuture(cache);
            }
            logger.debug("Loading a new value. cache: {}, loader: {}", cache, loader);
            return newFuture;
        }
        return returnCacheOrFuture(this.cacheEntry, this.loadFuture);
    } else {
        // The cache is still valid and no need to refresh.
        return returnCacheOrFuture(cacheEntry, loadFuture);
    }
}

private CompletableFuture<T> returnCacheOrFuture(@Nullable CacheEntry<T> cacheEntry,
                                                 CompletableFuture<T> loadFuture) {
    if (isValid(cacheEntry)) {
        return UnmodifiableFuture.completedFuture(cacheEntry.value);
    }
    return loadFuture;
}