code: @Implementation
    protected PersistableBundle getConfigForSubId(int subId) {
      PersistableBundle persistableBundle = bundles.get(subId);
      if (persistableBundle == null) {
        return new PersistableBundle();
      }
      return persistableBundle;
    }
docs: Returns {@link android.os.PersistableBundle} previously set by {@link #setConfigForSubId(int)},
  or default values for an invalid {@code subId}.