anchor.diff:                  // Output stream to write the file to
                   @Override
                   public OutputStream getOutputStream() {
  -                    return new FileOutputStream("/path/to/files/"
  -                        + file.getFileName());
  +                    try{
  +                        return new FileOutputStream("/path/to/files/"
  +                          + file.getFileName());
  +                        }catch (FileNotFoundException e) {
  +                                e.printStackTrace();
  +                            }
  +                    return null;
                   }
   
                   // Returns whether onProgress() is called during upload
  
positive.code:                 public void streamingFailed(StreamingErrorEvent event) {
                      Notification.show("Stream failed, fileName="
                          + event.getFileName());
                  }
              });
          }
  
negative.code: Label dropArea = new Label("Drop files here");
  FileDropTarget<Label> dropTarget = new FileDropTarget<>(dropArea, event -> {
  
      Collection<Html5File> files = event.getFiles();
      files.forEach(file -> {
          // Max 1 MB files are uploaded
          if (file.getFileSize() <= 1024 * 1024) {
  