The createAttachment method inside PO class calls the getAttachment method with the argument requery hardcoded to "false".
I changed createAttachment to take an argument, that is passed to the getAttachment allowing the developer to decide what to do. I also created a method with the old signature, and with false value to keep compatibility.
The patch for what I did is attached.
Ivy, thanks for your suggestion.
I think is not necessary as programatically you can achieve the intended behavior doing:
As a side note, when adding public methods the serialVersionUID must be regenerated.