startup.tjs

class SomeObject{
	function SomeObject(){
		this.setTimeout = KirikiriEmscriptenInterface.evalJS('(func,time)=>setTimeout(func,time)');
		this.setTimeout(this.timeout incontextof this,1000);
	};
	function timeout(){
		Debug.message("timeout is called");
		Debug.message(this); // Now It Works!
		Debug.message("this value is:" + this);
	}
}
var someObject = new SomeObject();