static Map<S, BWImage> loadBWImage_cached_cache = synchroTreeMap();

// s = snippetIDOrURL
static BWImage loadBWImage_cached(String s) {
  BWImage img = loadBWImage_cached_cache.get(s);
  if (img == null)
    loadBWImage_cached_cache.put(s, img = new BWImage(loadBufferedImage(s)));
  ret img;
}