how to check PhotoLibraryPermission in swift 3.0

cheakPermission.swift

  func checkPhotoLibraryPermission() {
        let status = PHPhotoLibrary.authorizationStatus()
        switch status {
        case .authorized:
            self.GetGalleryImage()

            break
        //handle authorized status
        case .denied, .restricted : break
        //handle denied status
        case .notDetermined:
            // ask for permissions
            PHPhotoLibrary.requestAuthorization() { status in
                switch status {
                case .authorized:
                    self.GetGalleryImage()

                    break
                // as above
                case .denied, .restricted: break
                // as above
                case .notDetermined: break
                    // won't happen but still
                }
            }
        }
    }