code: function scrollAnimate(opts){
    if(this.isScrolling) return
    const interval = this.interval
    const numbers = generateNumber(
      document.body.scrollTop || document.documentElement.scrollTop,
      opts.targetValue,
      opts.duration || 500,
      opts.easing || 'circleInOut',
      interval
    )
    const numbersLength = numbers.length
    let numberIndex = 0
    this.isScrolling = true
    const tick = setInterval(() => {
      window.scrollTo(0, numbers[numberIndex])
      numberIndex ++
      if(numberIndex >= numbersLength) {
        clearInterval(tick)
        this.isScrolling = false
        if (opts.onDone) opts.onDone()
      }
    }, interval)
  }
docs: opts: targetValue, duration = 500, easing = 'circleInOut', onDone,