public MultipartBuilder attachment(String content,String filename){
  ByteArrayInputStream is=new ByteArrayInputStream(content.getBytes());
  return bodyPart(new StreamDataBodyPart(ATTACHMENT_NAME,is,filename));
}

public MultipartBuilder attachment ( String content , String filename ) { ByteArrayInputStream is = new ByteArrayInputStream ( content . getBytes ( ) ) ; return bodyPart ( new StreamDataBodyPart ( ATTACHMENT_NAME , is , filename ) ) ; }
adds an attachment directly by content .
