public static StagingArea getInstance() {
    return new StagingArea();
  }
This is class encapsulates Map that maps ImageCacheKeys to EncodedImages pointing to
PooledByteBuffers. It is used by SimpleImageCache to store values that are being written to disk
cache, so that they can be returned by parallel cache get operations.
imagepipeline/src/main/java/com/facebook/imagepipeline/cache/StagingArea.java