docs: public double scoreOf(int[] sequence) {
  
      int[] given = new int[window() - 1];
      Arrays.fill(given, classIndex.indexOf(backgroundSymbol));
      double logProb = 0;
      for (int i = 0; i < length(); i++) {
        int label = sequence[i];
        logProb += condLogProbGivenPrevious(i, label, given);
        System.arraycopy(given, 1, given, 0, given.length - 1);
        given[given.length - 1] = label;
      }
      return logProb;
    }