请问如何处理照片资源未从iCloud下载的场景？ #251

    [[PHImageManager defaultManager] requestImageDataForAsset:asset options:imageRequestOptions resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
        if(imageData.length == 0){
         NSLog（@"该照片尚未从ICloud下载"）；
         }
     }];