message: optimize identifier name
diff: data() {
  return {
  beforePullDown: true,
  - isFinishing: false,
  + isRebounding: false,
  isPullingDown: false,
  pulling: false,
  isPullUpLoad: false,
  this.bubbleY = 0
  }
  - if (this.isFinishing) {
  + if (this.isRebounding) {
  this.pullDownStyle = `top:${Math.min(pos.y - 30, 10)}px`
  }
  })
  this.isPullUpLoad = true
  })
  },
  - _finishPullDown() {
  + _reboundPullDown() {
  const {stopTime = 600} = this.pullDownRefresh
  return new Promise((resolve) => {
  setTimeout(() => {
  - this.isFinishing = true
  + this.isRebounding = true
  this.scroll.finishPullDown()
  this.isPullingDown = false
  resolve()
  setTimeout(() => {
  this.pullDownStyle = `top:${this.pullDownInitTop}px`
  this.beforePullDown = true
  - this.isFinishing = false
  + this.isRebounding = false
  this.refresh()
  }, this.scroll.options.bounceTime)
  }
  setTimeout(() => {
  if (this.pullDownRefresh && this.isPullingDown) {
  this.pulling = false
  - this._finishPullDown().then(() => {
  + this._reboundPullDown().then(() => {
  this._afterPullDown()
  })
  } else if (this.pullUpLoad && this.isPullUpLoad) {
  