@Throws(IOException::class)
  fun size(): Long = cache.size()

  /** Max size of the cache (in bytes). */
  fun maxSize(): Long = cache.maxSize

  @Throws(IOException::class)
  override fun flush() {
    cache.flush()
  }

  @Throws(IOException::class)
  override fun close() {
    cache.close()
  }

  @get:JvmName("directory")
  val directory: File
    get() = cache.directory.toFile()