@Override
  @Nullable
  public T pop() {
    return maybeRemoveFromCurrentItems(mMap.removeFromEnd());
  }
Relies on {@link BucketMap} to implement pooling Items from the bucket with LRU key will be
removed first

@param <T>
imagepipeline/src/main/java/com/facebook/imagepipeline/memory/LruBucketsPoolBackend.java