@Override
  public boolean match(MatchNode matchNode, MatchEngine engine) {
    if (!super.match(matchNode, engine)) {
      return false;
    }

    RuleValue rule = matchNode.getRules().get(MatchProperties.EXPRENT_FIELD_NAME);
    if (rule != null) {
      if (rule.isVariable()) {
        return engine.checkAndSetVariableValue((String)rule.value, this.name);
      }
      else {
        return rule.value.equals(this.name);
      }
    }

    return true;
  }
@Override
  public boolean match(MatchNode matchNode, MatchEngine engine)