NSURL from PHAsset Swift

Question

I have been wondering if its possible to get NSURL from PHAsset (specially for all gallery photos) in iOS. I am still unable to find a good solution.

Someone shared a solution in here, https://stackoverflow.com/a/35099857/1084174

func getAssetUrl(mPhasset : PHAsset, completionHandler : ((responseURL : NSURL?) -> Void)){

    if mPhasset.mediaType == .Image {
        let options: PHContentEditingInputRequestOptions = PHContentEditingInputRequestOptions()
        options.canHandleAdjustmentData = {(adjustmeta: PHAdjustmentData) -> Bool in
            return true
        }
        mPhasset.requestContentEditingInputWithOptions(options, completionHandler: {(contentEditingInput: PHContentEditingInput?, info: [NSObject : AnyObject]) -> Void in
            completionHandler(responseURL : contentEditingInput!.fullSizeImageURL)
        })
    } else if mPhasset.mediaType == .Video {
        let options: PHVideoRequestOptions = PHVideoRequestOptions()
        options.version = .Original
        PHImageManager.defaultManager().requestAVAssetForVideo(mPhasset, options: options, resultHandler: {(asset: AVAsset?, audioMix: AVAudioMix?, info: [NSObject : AnyObject]?) -> Void in

            if let urlAsset = asset as? AVURLAsset {
                let localVideoUrl : NSURL = urlAsset.URL
                completionHandler(responseURL : localVideoUrl)
            } else {
                completionHandler(responseURL : nil)
            }
        })
    }

}

But the problem is this solution does not work consistently.

mPhasset.requestContentEditingInputWithOptions(options, completionHandler: {(contentEditingInput: PHContentEditingInput?, info: [NSObject : AnyObject]) -> Void in
    completionHandler(responseURL : contentEditingInput!.fullSizeImageURL)
})

Sometimes, completionHandler is not being called. Please someone explain whats happening.