         self.shouldAppend = shouldAppend
         self.appendMarker = appendMarker
 
-        if writeToFile is NSString {
+        if writeToFile is String {
             writeToFileURL = URL(fileURLWithPath: writeToFile as! String)
         }
         else if writeToFile is URL {

    @discardableResult open func rotateFile(to archiveToFile: Any) -> Bool {
        var archiveToFileURL: URL? = nil

        if archiveToFile is NSString {
            archiveToFileURL = URL(fileURLWithPath: archiveToFile as! String)
        }
        else if archiveToFile is URL {

        }
        else {
            writeToFileURL = nil
            fatalError("FileDestinations must be initialized with a URL or a String")
        }

        super.init(owner: owner, identifier: identifier)
