How to use the @hpcc-js/layout.Popup function in @hpcc-js/layout

.addLayer(new AbsoluteSurface().widgetX(30).widgetY(10).widgetWidth("40").widgetHeight("60").widget(new Column()
                                        .columns(data.ND.subjects.columns)
                                        .data(data.ND.subjects.data)
                                    )
                                    ));
                                break;
                            case Modal:
                                render(new Modal()
                                    .widget(new Pie()
                                        .columns(data.TwoD.subjects.columns)
                                        .data(data.TwoD.subjects.data)
                                    )
                                );
                                break;
                            case Popup:
                                render(new Popup()
                                    .widget(new Surface()
                                        .widget(new Icon()
                                            .faChar("\uF007")
                                        )
                                    )
                                );
                                break;
                            case Tabbed:
                                render(new Tabbed()
                                    .addTab(new Pie()
                                        .columns(data.TwoD.subjects.columns)
                                        .data(data.TwoD.subjects.data)
                                        , "Pie Chart", true)
                                    .addTab(
                                        new Line()
                                            .columns(data.ND.subjects.columns)

padding: "0px 5px",
                    class: "close",
                    font: "FontAwesome"
                }
            ])
            .on("click", function (ann) {
                if (ann.class === "close") {
                    context._popup
                        .visible(false)
                        .popupState(false)
                        .render()
                        ;
                }
            })
            ;
        this._popup = new Popup()
            .size({ width: 400, height: 400 })
            .position("absolute")
            .widget(this._popupSurface)
            ;
    }