public static String getTileNumber(TileServer tileServer, double lat, double lon, int zoom) {
        int xtile = (int) Math.floor((lon + 180) / 360 * (1 << zoom));
        int ytile = (int) Math.floor((1 - Math.log(Math.tan(Math.toRadians(lat)) + 1 / Math.cos(Math.toRadians(lat))) / Math.PI) / 2 * (1 << zoom));
        return getTileString(tileServer, xtile, ytile, zoom);
    }