init {
	screen := {
					"widgets": {
										"001": {"type": "label", "text": "a", "state": 0, "x": 100, "y": 100}, 
										"002": {"type": "textInput", "text": "", "state": 0}
									}, 
					"layout": true,
					"extra": {
						"001": {"type": "label", "text": "a", "state": 0, "x": 100, "y": 100}
					}
				}
}

native channel ScreenUpdate {
	in screen(curSc: Json, update(curSc, nextSc)) = nextSc
}

native channel 
