private static <K, V> void maybeNotifyExclusiveEntryRemoval(@Nullable Entry<K, V> entry) {
    if (entry != null && entry.observer != null) {
      entry.observer.onExclusivityChanged(entry.key, false);
    }
  }
Notifies the client that the cache no longer tracks the given items.

<p>This method invokes the external {@link CloseableReference#close} method, so it must not be
called while holding the <code>this</code> lock.
imagepipeline-base/src/main/java/com/facebook/imagepipeline/cache/LruCountingMemoryCache.java