old_contents: export default function (task) {
    if (!task) {
      return new Promise(requestAnimationFrame)
    }
    return new Promise(resolve => requestAnimationFrame(() => {
      task()
      resolve()
    }))
  }
  
new_contents: const nextTick = (typeof window === 'undefined') ? process.nextTick : requestAnimationFrame
  
  export default function (task) {
    if (!task) {
      return new Promise(nextTick)
    }
    return new Promise(resolve => nextTick(() => {
      task()
      resolve()
    }))
  }
  
subject: fix (nextTick): add Node support