class Counter {
    value: Number
    lastEvent: String

    function activate(self: Counter, event: Event): Unit {
        self.lastEvent = event.kind
        self.change()
    }

    function change(self: Counter): Unit {
        self.value = 10
    }
}

class DemoCounter: Counter {
    function change(self: DemoCounter): Unit {
        self.value = 12
    }
}

model = DemoCounter(9, "等待点击")
first = ui.textOf(model, "value", 2)
second = ui.textOf(model, "value", 2)
eventName = ui.textOf(model, "lastEvent")
button = Button("调用继承方法，再分派到覆盖方法")
button.onClick(model.activate)
page = Page()
page.render(Column(24, 16, TextBlock("Endor class：继承、self 与动态方法分派", 2), Row(0, 16, first, second), button, eventName))