Can I make column group in ColumnSetContainer?

Hello,

I develop on 5.1 SDK.

I'd like to make column group in ColumnSetContainer.

However, it is not possible with the code below:

    <lists:ColumnContainer uid="...">

        <lists:dataInfo>

            <lists:ColumnDataSourceInfo requestedProperties="{['prop1', 'prop2']}"/>

        </lists:dataInfo>

        <lists:component>

            <mx:AdvancedDataGridColumnGroup headerText="Item Group">

                <mx:AdvancedDataGridColumn

                    headerText="Item1"

                    dataField="prop1"/>

                <mx:AdvancedDataGridColumn

                    headerText="Item1"

                    dataField="prop2"/>

            </mx:AdvancedDataGridColumnGroup>

        </lists:component>

    </lists:ColumnContainer>

Can I make column group in ColumnSetContainer?

Thanks,

KoMizutani