public int getData(@NotNull String key1, @NotNull String key2) {
    final Deque<String> list = myDataMap.get(key1);
    if (list == null) return 0;

    int result = 0;
    for (final String s : list) {
      if (s.equals(key2)) result++;
    }
    return result;
  }
public int getData(@NotNull String key1, @NotNull String key2)