public static AttachmentBuilder attachment(File file) {
   AttachmentBuilder builder = new AttachmentBuilder();
   builder.fileName = file.getName();
   FileDataSource fileDataSource = new FileDataSource(file);
   builder.fileContent = new DataHandler(fileDataSource);
   return builder;
 }
 public static AttachmentBuilder attachment(String uri) {
   AttachmentBuilder builder = new AttachmentBuilder();
   File fileToUpload = new File(uri);
   FileDataSource fileDataSource = new FileDataSource(fileToUpload);
   builder.fileName = fileToUpload.getName();
   builder.fileContent = new DataHandler(fileDataSource);
   return builder;
 }