let fileManager = FileManager.default
    let documentsURL = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]

    public struct SearchPathDomainMask : OptionSet {

        public init(rawValue: UInt)

        
        public static var userDomainMask: FileManager.SearchPathDomainMask { get } // user's home directory --- place to install user's personal items (~)

        public static var localDomainMask: FileManager.SearchPathDomainMask { get } // local to the current machine --- place to install items available to everyone on this machine (/Library)

        public static var networkDomainMask: FileManager.SearchPathDomainMask { get } // publically available location in the local area network --- place to install items available on the network (/Network)

        public static var systemDomainMask: FileManager.SearchPathDomainMask { get } // provided by Apple, unmodifiable (/System)

        public static var allDomainsMask: FileManager.SearchPathDomainMask { get } // all domains: all of the above and future items
    }

    let documentsURL = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
    //결과값
    //file:///Users/janghyowon/Library/Developer/CoreSimulator/Devices/6F684BD3-AD68-416F-98A2-DF6333813AFD/data/Containers/Data/Application/1C8689AA-6EF7-44A2-B85A-B2E138EDB7D2/Documents/
    
    let documentsURL = fileManager.urls(for: .documentDirectory, in: .allDomainsMask)[0]
    //결과값
    //file:///Users/janghyowon/Library/Developer/CoreSimulator/Devices/6F684BD3-AD68-416F-98A2-DF6333813AFD/data/Containers/Data/Application/B177AA48-D9BB-4921-B264-82230C49722F/Documents/