@Override
    public void increaseCachesFound(final int by) {
        //not supported
    }
For geocaching.su geocode is not immutable because first two letters
indicate cache type, which may change. However ID is immutable, that's why it's preferred
to use ID in all the places

@param geocode cache's geocode like MV15736
@return cache ID, i.e. 15736
main/src/main/java/cgeo/geocaching/connector/su/SuConnector.java