我有以下Objective-C代码:NSFileWrapper*fileWrapper;NSMutableDictionary*wrappers=[NSMutableDictionarydictionary];...fileWrapper=[[NSFileWrapperalloc]initDirectoryWithFileWrappers:wrappers];我尝试将上面的代码转换为Swift:varfileWrapper:NSFileWrapper?letwrappers=NSMutableDictionary(dictionary:[:])....fileWrapper=NSFil