code: protected boolean validOutcome(String outcome, Sequence sequence) {
      if (outcome.equals(CONTINUE)) {
        List tags = sequence.getOutcomes();
        int li = tags.size() - 1;
        if (li == -1) {
          return false;
        }
        else if (((String) tags.get(li)).equals(OTHER)) {
          return false;
        }
      }
      return true;
    }
docs: This method determines wheter the outcome is valid for the preceeding sequence.
  This can be used to implement constraints on what sequences are valid.
  @param outcome The outcome.
  @param sequence The precceding sequence of outcomes assignments.
  @return true is the outcome is valid for the sequence, false otherwise.