private void pushEnd(int end) {
        if (_endArray == null)
            _endArray = new int[10];
        else if (_level >= _endArray.length) {
            int[] temp = new int[_level * 2 + 1];
            System.arraycopy(_endArray, 0, temp, 0, _level);
            _endArray = temp;
        }
        _endArray[_level++] = end;
    }