How to use the @vue/runtime-core.getCurrentInstance function in @vue/runtime-core

leaveActiveClass = `${name}-leave-active`,
  leaveToClass = `${name}-leave-to`,
  ...baseProps
}: TransitionProps): BaseTransitionProps {
  if (!css) {
    return baseProps
  }

  const instance = getCurrentInstance()!
  const durations = normalizeDuration(duration)
  const enterDuration = durations && durations[0]
  const leaveDuration = durations && durations[1]
  const { appear, onBeforeEnter, onEnter, onLeave } = baseProps

  // is appearing
  if (appear && !getCurrentInstance()!.isMounted) {
    enterFromClass = appearFromClass
    enterActiveClass = appearActiveClass
    enterToClass = appearToClass
  }

  type Hook = (el: HTMLElement, done?: () => void) => void

  const finishEnter: Hook = (el, done) => {
    removeTransitionClass(el, enterToClass)
    removeTransitionClass(el, enterActiveClass)
    done && done()
  }

  const finishLeave: Hook = (el, done) => {
    removeTransitionClass(el, leaveToClass)
    removeTransitionClass(el, leaveActiveClass)