선택된 폴더에 하위폴더 생성하기.. Create the sub_folder where selected folder with Swift

import Cocoa
 
class ViewController: NSViewController {
 
  
 
    @IBAction func open(sender: AnyObject) {
        
       
        var myOpenDialog: NSOpenPanel = NSOpenPanel()
        myOpenDialog.canChooseDirectories = true
        myOpenDialog.runModal()
        
        var path = myOpenDialog.URL?.path
        
        var path1 = String(path!) + "/test"   //<-  dialog로 선택된 폴더하위에 생성할 폴더이름을 지정
        let fileManager = NSFileManager.defaultManager()
        do
        {
             //withIntermediateDirectories: false   <-이면 중복된 폴더가 있을때 에러발생
             try fileManager.createDirectoryAtPath(path1, withIntermediateDirectories: true, attributes: nil)
        }
        catch let error as NSError
        {
            print("Error while creating a folder.")
        }
        
        
    }
 
}