public Preference<Boolean> getBoolean(@StringRes int prefKey, @BoolRes int defaultValue) {
    return mRxSharedPreferences.getBoolean(
        mResources.getString(prefKey), mResources.getBoolean(defaultValue));
  }
@Test
  public void testConvertTheme() {
    SharedPrefsHelper.setPrefsValue(
        "settings_key_keyboard_theme_key", "28860f10-cf16-11e1-9b23-0800200c9a66");
    SharedPrefsHelper.setPrefsValue(RxSharedPrefs.CONFIGURATION_VERSION, 10);

    SharedPreferences preferences =
        PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    Assert.assertFalse(preferences.contains("theme_28860f10-cf16-11e1-9b23-0800200c9a66"));

    new RxSharedPrefs(getApplicationContext(), this::testRestoreFunction);

    Assert.assertTrue(preferences.contains("theme_28860f10-cf16-11e1-9b23-0800200c9a66"));
    Assert.assertTrue(preferences.getBoolean("theme_28860f10-cf16-11e1-9b23-0800200c9a66", false));
  }