persist.js

// time iterator (read: debounce)
if (timeIterator === null) {
  timeIterator = setInterval(processNextReducer, debounce)
}

function flush () {
  storesToProcess.forEeach(processNextReducer)
}

function processNextReducer () {
  if (storesToProcess.length === 0) {
    clearInterval(timeIterator)
    timeIterator = null
    return
  }

  let key = storesToProcess[0]
  let storageKey = createStorageKey(key)
  let endState = transforms.reduce((subState, transformer) => transformer.in(subState, key), stateGetter(store.getState(), key))
  if (typeof endState !== 'undefined') storage.setItem(storageKey, serializer(endState), warnIfSetError(key))
  storesToProcess.shift()
}