*
   * The iterator supports [MutableIterator.remove]. Removing a URL from the iterator evicts the
   * corresponding response from the cache. Use this to evict selected responses.
   */
  @Throws(IOException::class)
  fun urls(): MutableIterator<String> {
    return object : MutableIterator<String> {
      private val delegate: MutableIterator<DiskLruCache.Snapshot> = cache.snapshots()

   * to do so leaks open files!
   */
  @Synchronized
  @Throws(IOException::class)
  fun snapshots(): MutableIterator<Snapshot> {
    initialize()
    return object : MutableIterator<Snapshot> {
      /** Iterate a copy of the entries to defend against concurrent modification errors. */
      private val delegate = ArrayList(lruEntries.values).iterator()