Usage is as follows

// 1
let o = {val: 0}
let ac = tween(o).to(1, {val: 100}, {
	onComplate() {
		console.log("onComplate")
	},
	onUpdate(t) {
		console.log("time:", t);
	},
	easing: "quadOut"
}).delay(1).call(() => {
	console.log("call");
}).to(0.4, {val: 120}).start();

setTimeout(() => {
	ac.start() // ❌ No longer valid
}, 2000)

// 2
let o = {val: 0}
let ac = tween(o).delay(1).by(1, {val: 10});
//  Let it act as branch easing

tween(o).repeat(10, ac).start();
// or 
tween({}).repeat(10, ac).start();

setTimeout(() => {
	ac.start() //  ✔️ Still valid
}, 21000)

// 3
let o1 = {val: 0}
let o2 = {val: 100}
let ac1 = tween(o1).to(1, {val: 300});
let ac2 = tween(o2).to(0.5, {val: 100});
tween(o1).parallel(ac1, ac2).start();

// 4
let o = {val: 0}
let ac = tween(o).to(2, {val: 100}).start();
setTimeout(() => { 
	ac.pause();
	// or
	Tween.pauseOffTarget(o);
}, 1000)

setTimeout(() => {
	ac.start();
	// or
	Tween.resumeOffTarget(o);
}, 1800)