Strange Design Choice for Harvester Registration

See the method 

public void visit(HarvesterRegistrationResponse msg)  

in HarvestController Server. The response is sent to a queue and is then picked up by a random harvester, which returns it to the queue if the it was meant for a different harvester. Why not use a unique reply queue, or even a Topic so that every harvester reads the reply exactly once. Also the call "close()" doesn't shut the HaCo down.