function* test() {
	console.log("Started");
	yield sleep(1234);
	console.log("End");
	yield sleep(2345);
	console.log("============");
};
var gen = test();
function sleep(ms) { setTimeout(() => gen.next(), ms || 1); }
gen.next();
// 等待完成后，test 变成普通函数了，会立即执行，不需要 gen.next();
gen = test();