Implement anonymous inner classes in kotlin

1. The conventional way to implement anonymous inner classes

valueAnimator.addUpdateListener(object :AnimatorUpdateListener {
    override fun onAnimationUpdate(animation: ValueAnimator?) {
        currentPoint = animation?.animatedValue as Point
        postInvalidate()
    }

})

2. Anonymous inner class of lambda expression version

valueAnimator.addUpdateListener { animation ->
    currentPoint = animation?.animatedValue as Point
    postInvalidate()
}