@Override
  public void clear() {
    ArrayList<Entry<K, V>> oldExclusives;
    ArrayList<Entry<K, V>> oldEntries;
    synchronized (this) {
      oldExclusives = mExclusiveEntries.clear();
      oldEntries = mCachedEntries.clear();
      makeOrphans(oldEntries);
    }
    maybeClose(oldEntries);
    maybeNotifyExclusiveEntryRemoval(oldExclusives);
    maybeUpdateCacheParams();
  }
Removes all the items from the cache.
imagepipeline-base/src/main/java/com/facebook/imagepipeline/cache/LruCountingMemoryCache.java