private static DiskStorageCache buildDiskStorageCache(
      DiskCacheConfig diskCacheConfig, DiskStorage diskStorage) {
    return buildDiskStorageCache(diskCacheConfig, diskStorage, Executors.newSingleThreadExecutor());
  }
Factory for the default implementation of the FileCacheFactory.
imagepipeline/src/main/java/com/facebook/imagepipeline/core/DiskStorageCacheFactory.java