Function callback

plugins/tweenSystem.js:426–431

(value)

    const parts = propertyPath.split('.');
    const lastKey = parts.pop();
    const callback = (value) =>
    {
        let obj = target;
        for (const k of parts) obj = obj[k];
        obj[lastKey] = value;
    };
    return new Tween(callback, start, end, duration, options);
}