     // string encoding
     
     /// reinterpret file with the desired encoding and show error dialog if failed
-    @discardableResult
     func reinterpretAndShowError(encoding: String.Encoding) {
         
         do {

            switch option {
            case .ignore:
                break
                
            case .notify:
                self?.notifyExternalFileUpdate()
                
            case .revert:
                guard let strongSelf = self,
                    let fileURL = strongSelf.fileURL,
                    let fileType = strongSelf.fileType
                    else { return }
                
                do {
                    try strongSelf.revert(toContentsOf: fileURL, ofType: fileType)
                } catch {
                    strongSelf.presentErrorAsSheet(error)
                }
            }
        }
    }

        // do nothing
        if option == .ignore { return }
        
        // don't check twice if already notified
        guard !self.isExternalUpdateAlertShown else { return }
        
        guard let fileURL = self.fileURL else { return }
        
