code: @Override
    public boolean eIsSet(int featureID)
    {
      switch (featureID)
      {
        case SimpleAntlrPackage.GROUP__ELEMENTS:
          return elements != null && !elements.isEmpty();
      }
      return super.eIsSet(featureID);
    }
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated