<zk>
    <portallayout id="portalLayout" maximizedMode="whole">
        <portalchildren style="padding: 5px" width="30%">
            <panel id="calendar" title="Calendar" border="normal" collapsible="false" closable="false" maximizable="false" style="margin-bottom:10px">
                <panelchildren>
                    <calendar/>
                </panelchildren>
            </panel>
            <panel id="translate" title="Translate" border="normal" collapsible="true" closable="true" maximizable="true" style="margin-bottom:10px">
                <panelchildren>
                    <calendar/>
                </panelchildren>
            </panel>
        </portalchildren>

        <portalchildren style="padding: 5px" width="40%">
        </portalchildren>

        <portalchildren style="padding: 5px" width="30%">
        </portalchildren>
    </portallayout>
</zk>

Uncaught TypeError: this.$n_(...).firstChild.focus is not a function
    at subclass._openPopup (za11y.wpd:2:32623)
    at subclass.doKeyDown_ (za11y.wpd:2:32956)
    at __webpack_modules__../zk/src/main/resources/web/js/zk/widget.ts.Widget.doKeyDown_ (zk.wpd:33598:19)
    at __webpack_modules__../zul/src/main/resources/web/js/zul/Widget.ts.Widget.doKeyDown_ (zk.wpd:40295:41)
    at __webpack_modules__../zk/src/main/resources/web/js/zk/widget.ts.Widget.doKeyDown_ (zk.wpd:33598:19)
    at __webpack_modules__../zul/src/main/resources/web/js/zul/Widget.ts.Widget.doKeyDown_ (zk.wpd:40295:41)
    at _doEvt (zk.wpd:27501:50)
    at HTMLDocument.<anonymous> (zk.wpd:27600:13)
    at HTMLDocument.dispatch (zk.wpd:13448:48)
    at elemData.handle (zk.wpd:13300:47)