ViewGroupChildren
constructor(container: ViewGroup, insert: (index: Int, widget: Widget<View>) -> Unit = { index, widget ->
container.addView(widget.value, index)
}, remove: (index: Int, count: Int) -> Unit = { index, count ->
container.removeViews(index, count)
}, onModifierUpdated: (index: Int, widget: Widget<View>) -> Unit = { _, _ ->
container.requestLayout()
})