如何在Google Drive API中禁用文件夹的递归（Swift 5）

在我的应用中，我使用Google Drive API。我得到文件列表并将其加载到TableView。但是在TableView中，我看到了根目录中的文件和文件夹以及子文件夹中的文件和文件夹。但是，仅当我点击相应的行时，才需要导航到子文件夹中的文件。如何禁用递归？以及如何在didSelectRow函数的子文件夹内实现转换？感谢帮助。

...
var unreformedFileList: [AnyObject] = []
var fileListTicket: GTLRServiceTicket?
...
private lazy var driveService: GTLRDriveService = {
        let service = GTLRDriveService()
        if let user = GlobalEntitie.Variable.googleUser {
        service.authorizer = user.authentication.fetcherAuthorizer()
        }
        service.shouldFetchNextPages = true
        service.isRetryEnabled = true
        return service
    }()
...
var files: [FileModelProtocol] {
        guard let files = unreformedFileList as? [GTLRDrive_File] else { return [] }
        return files.map { GoogleDriveFileModel($0) }
    }
...
func fetchFileList(path: String?, _ completion: @escaping () -> Void) {
        let query = GTLRDriveQuery_FilesList.query()
        query.fields = "kind,nextPageToken,files(mimeType,id,kind,name,webViewLink,thumbnailLink,trashed)"

        fileListTicket = driveService.executeQuery(query,
                                                   completionHandler: { [weak self] (_, resultObject, error) in
                                                    
                                                    if let error = error {
                                                        debugPrint("driveService.executeQuery error: \(error.localizedDescription)")
                                                        return
                                                    }
                                                    guard let self = self,
                                                          let fileList = resultObject as? GTLRDrive_FileList,
                                                          let unreformedFileList = fileList.files else { return }
                                                    self.unreformedFileList = []
                                                for file in unreformedFileList {
                                                    
                                                    if file.mimeType == "application/vnd.google-apps.folder" {
                                                        self.unreformedFileList.insert(file, at: 0)
                                                    } else {
                                                        if file.mimeType == "audio/mpeg" ||
                                                            file.mimeType == "audio/x-wav" ||
                                                            file.mimeType == "audio/aac" {
                                                            self.unreformedFileList.append(file)
                                                        }
                                                    }
                                                }
                                                    self.fileListTicket = nil

                                                    completion()
        })
    }