def shutdown
      transition :shutdown
      kill_actors
      close_comm
      NodeCache.delete @id
      MailboxManager.delete Thread.mailbox
      instance_variables.each { |iv| remove_instance_variable iv }
    end
def shutdown
      transition :shutdown
      kill_actors
      close_comm
      NodeCache.delete @id
      MailboxManager.delete Thread.mailbox
      instance_variables.each { |iv| remove_instance_variable iv }
    end
Graceful termination of the node