/**
         *  factory reset.
         */
        public static void AssetBundle_FactoryReset(Action succeeded, Action <FactoryResetError, string> failed)
        {
            var unloaded = Autoya.AssetBundle_UnloadOnMemoryAssetBundles();

            if (!unloaded)
            {
                failed(FactoryResetError.UnloadAssetBundles_Failed, "failed to unload AssetBundles on memory.");
                return;
            }

            var discarded = Autoya.AssetBundle_DeleteAllStorageCache();

            if (!discarded)
            {
                failed(FactoryResetError.DeleteAllStorageCache_Failed, "failed to delete cached AssetBundles.");
                return;
            }

            Autoya.AssetBundle_DiscardAssetBundleList(
                () =>
            {
                succeeded();
            },
                (err, reason) =>
            {
                failed(FactoryResetError.DiscardAssetBundleList_Failed, "failed to delete AssetBundleList.");
            }
                );
        }