- (PHImageRequestID)requestAVAssetForVideo:(PHAsset *)asset options:(nullable PHVideoRequestOptions *)options resultHandler:(void (^)(AVAsset *__nullable asset, AVAudioMix *__nullable audioMix, NSDictionary *__nullable info))resultHandler;

能取出所有的使用者相簿，包含iCloud的，如果本地相簿沒有，
requestAVAssetForVideo 取出相簿為空 asset = nil; info中也會是空資料；

對於這種相簿檔案使用時候。需要在PHVideoRequestOptions中新增：options.networkAccessAllowed = true;
當然有一段下載時間。

PHVideoRequestOptions *options = [[PHVideoRequestOptions alloc] init];
                options.version = PHImageRequestOptionsVersionCurrent;
                options.deliveryMode = PHVideoRequestOptionsDeliveryModeAutomatic
 
;
//                options.networkAccessAllowed = true; // iCloud的相簿需要網路許可
                @MVU_WEAKIFY(self);
                [[PHImageManager defaultManager] requestAVAssetForVideo:photo options:options resultHandler:^(AVAsset * _Nullable asset, AVAudioMix * _Nullable audioMix, NSDictionary * _Nullable info) {
                    @MVU_STRONGIFY
 
(self);
                    if(![asset isKindOfClass:[AVURLAsset class]]){
                        return;
                    }

                    AVURLAsset *urlAsset = (AVURLAsset *)asset;
                    dispatch_async(dispatch_get_main_queue(), ^{

                        [self.navigationController pushViewController:vc animated:YES];
                    });
                }];