sclass SnippetTitles {
  Map<Long, S> titles = synchroHashMap();
  
  S get(S snippetID) {
    if (snippetID == null) null;
    long id = parseSnippetID(snippetID);
    if (titles.containsKey(id))
      ret titles.get(id);
    else {
      S title = getSnippetTitle_safe(snippetID);
      titles.put(id, title);
      ret title;
    }
  }
  
  // like get, but only check the cache
  S probe(S id) {
    ret titles.get(parseSnippetID(id));
  }
  
  // advanced uses
  
  void put(S id, S title) {
    titles.put(parseSnippetID(id), title);
  }
  
  bool has(S id) {
    ret titles.containsKey(parseSnippetID(id));
  }
  
  void clear() { titles.clear(); }
}