code: public void setGuarded(RuleElement newGuarded)
    {
      if (newGuarded != guarded)
      {
        NotificationChain msgs = null;
        if (guarded != null)
          msgs = ((InternalEObject)guarded).eInverseRemove(this, EOPPOSITE_FEATURE_BASE - SimpleAntlrPackage.RULE_ELEMENT__GUARDED, null, msgs);
        if (newGuarded != null)
          msgs = ((InternalEObject)newGuarded).eInverseAdd(this, EOPPOSITE_FEATURE_BASE - SimpleAntlrPackage.RULE_ELEMENT__GUARDED, null, msgs);
        msgs = basicSetGuarded(newGuarded, msgs);
        if (msgs != null) msgs.dispatch();
      }
      else if (eNotificationRequired())
        eNotify(new ENotificationImpl(this, Notification.SET, SimpleAntlrPackage.RULE_ELEMENT__GUARDED, newGuarded, newGuarded));
    }
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated