code: @Override
    public Set<String> getFileEntries() throws
        IOException
    {
      synchronized (zip)
      {
        if (allEntries == null)
        {
          listEntries();
        }
        return Collections.unmodifiableSet(fileEntries);
      }
    }
docs: /* (non-Javadoc)
  @see com.adobe.epubcheck.ocf.OCFPackage#getFileEntries()