code: private static final void processCellUnaryRules(final CnfGrammar grammar, final int start, final int end,
              final ChartCell cell, final Scorer scorer) {
          // Apply unary rules.
          ScoresSnapshot scoresSnapshot = cell.getScoresSnapshot();
          int[] nts = cell.getNts();
          for(final int parentNt : nts) {
              for (final Rule r : grammar.getUnaryRulesWithChild(parentNt)) {
                  double score = scorer.score(r, start, end, end)
                          + scoresSnapshot.getScore(r.getLeftChild());
                  cell.updateCell(r.getParent(), score, end, r);
              }
          }
      }
docs: Process a cell, unary rules only.