如何在使用PHAssetChangeRequest.FromVideo时避免重复的视频文件

import Photos

func addVideoToAlbum(videoURL: URL) {
    let fetchOptions = PHFetchOptions()
    fetchOptions.predicate = NSPredicate(format: "mediaType = %d", PHAssetMediaType.video.rawValue)
    
    let fetchResult = PHAsset.fetchAssets(with: fetchOptions)
    
    var existingIdentifiers = Set<String>()
    
    fetchResult.enumerateObjects { (asset, _, _) in
        existingIdentifiers.insert(asset.localIdentifier)
    }
    
    let changeRequest = PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL)
    guard let createdAsset = changeRequest?.placeholderForCreatedAsset else {
        // 处理创建失败的情况
        return
    }
    
    if existingIdentifiers.contains(createdAsset.localIdentifier) {
        // 视频文件已存在于相册中，不需要重复添加
        return
    }
    
    // 添加视频文件到相册
    PHPhotoLibrary.shared().performChanges({
        let albumChangeRequest = PHAssetCollectionChangeRequest(for: album)
        let assetPlaceholder = changeRequest?.placeholderForCreatedAsset
        albumChangeRequest?.addAssets([assetPlaceholder] as NSFastEnumeration)
    }) { (success, error) in
        if success {
            // 视频文件添加成功
        } else {
            // 处理添加失败的情况
        }
    }
}