@VisibleForTesting
    public static <K, V> CountingMemoryCache.Entry<K, V> of(
        final K key,
        final CloseableReference<V> valueRef,
        final @Nullable EntryStateObserver<K> observer) {
      return of(key, valueRef, -1, observer);
    }
Creates a new entry with the usage count of 0.
imagepipeline-base/src/main/java/com/facebook/imagepipeline/cache/CountingMemoryCache.java