code: private InputStream safeOpen(String file) {
      URL url = bundle.getEntry(file);
      if (url != null) {
        try {
          return url.openStream();
        } catch (IOException e) {
          // if we get an IOException just return null for default page.
        }
      }
      return null;
    }
docs: Attempt to open the file in the bundle and return null if something goes wrong.