<zk>
    <window>
        <tree multiple="true" checkmark="true" mold="paging" pageSize="3">
            <treecols>
                <treecol label="Test"/>
                <treecol label="Test"/>
                <treecol label="Test"/>
                <treecol label="Test"/>
            </treecols>
            <treechildren>
                <!-- the draggable attribute cause error while page changed -->
                <treeitem draggable="true" label="Test" />
                <treeitem draggable="true" label="Test" />
                <treeitem draggable="true" label="Test" />
                <treeitem label="Test" />
            </treechildren>
        </tree>
    </window>
</zk>