override fun getRootDir(): String {
    val nsUserDomainMask = 1UL
    val nsCachesDirectory = 13UL
    val cacheDirectoryList = NSFileManager.defaultManager().URLsForDirectory(
        nsCachesDirectory,
        nsUserDomainMask
    )

    return (cacheDirectoryList.first() as? NSURL)?.path() ?: ""
}