public void incData(String key1, String key2) {
    Deque<String> list = myDataMap.get(key1);
    if (list == null) {
      myDataMap.put(key1, list = new ArrayDeque<>());
    }
    list.addFirst(key2);
    if (list.size() > StatisticsManager.OBLIVION_THRESHOLD) {
      list.removeLast();
    }

    advanceRecencyStamps(key1, key2);
  }
public void incData(String key1, String key2)