code: @Override
  	public boolean eIsSet(int featureID)
  	{
  		switch (featureID)
  		{
  			case XbasePackage.XIF_EXPRESSION__IF:
  				return if_ != null;
  			case XbasePackage.XIF_EXPRESSION__THEN:
  				return then != null;
  			case XbasePackage.XIF_EXPRESSION__ELSE:
  				return else_ != null;
  			case XbasePackage.XIF_EXPRESSION__CONDITIONAL_EXPRESSION:
  				return conditionalExpression != CONDITIONAL_EXPRESSION_EDEFAULT;
  		}
  		return super.eIsSet(featureID);
  	}
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated