@NonNull
    public static ImmutablePair<String, String> getTokenPair(final int tokenPublicPrefKey, final int tokenSecretPrefKey) {
        return new ImmutablePair<>(getString(tokenPublicPrefKey, null), getString(tokenSecretPrefKey, null));
    }
this method is to be solely used for auto-fixing GC username, see MainActivity.UpdateUserInfoHandler
main/src/main/java/cgeo/geocaching/settings/Settings.java