// elements are put to front when added (not when accessed)
persistable sclass MRUCache<A, B> extends LinkedHashMap<A, B> {
  int maxSize = 10;

  *() {}
  *(int *maxSize) {}
  
  protected bool removeEldestEntry(Map.Entry eldest) {
    ret size() > maxSize;
  }
  
  O _serialize() {
    ret ll(maxSize, cloneLinkedHashMap(this));
  }
  
  static MRUCache _deserialize(L l) {
    new MRUCache m;
    m.maxSize = (int) first(l);
    m.putAll((LinkedHashMap) second(l));
    ret m;
  }
}