#vulnerable code 
                              public void reopen(int size) {
    size = (size == 13 || size == 9) ? size : 19;
    if (size != boardSize) {
      boardSize = size;
      initialize();
      forceRefresh = true;
    }
  } 
                            #location 5 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                              public void reopen(int size) {
    size = (size >= 2) ? size : 19;
    if (size != boardSize) {
      boardSize = size;
      Zobrist.init();
      clear();
      Lizzie.leelaz.sendCommand("boardsize " + boardSize);
      forceRefresh = true;
    }
  }