@Override
  /**
   * Returns a list of entries.
   *
   * <p>This list is immutable.
   */
  public List<Entry> getEntries() throws IOException {
    EntriesCollector collector = new EntriesCollector();
    FileTree.walkFileTree(mVersionDirectory, collector);
    return collector.getEntries();
  }
Creates the directory (and its parents, if necessary). In case of an exception, log an error
message with the relevant parameters

@param directory the directory to create
@param message message to use
@throws IOException
imagepipeline-base/src/main/java/com/facebook/cache/disk/DefaultDiskStorage.java