docs: public int levenshtein() {
          int levenshtein = 0;
          int insertions = 0;
          int deletions = 0;
          for (Change aDiff : getChangeList()) {
              switch (aDiff.operation) {
                  case INSERT:
                      insertions += aDiff.text.length();
                      break;
                  case DELETE:
                      deletions += aDiff.text.length();
                      break;
                  case EQUAL:
                      // A deletion and an insertion is one substitution.
                      levenshtein += Math.max(insertions, deletions);
                      insertions = 0;
                      deletions = 0;
                      break;
              }
          }
          levenshtein += Math.max(insertions, deletions);
          return levenshtein;
      }