code: def handle_call_response(self, result, node):
          
          if not result[0]:
              log.warning("no response from %s, removing from router", node)
              self.router.remove_contact(node)
              return result
  
          log.info("got successful response from %s", node)
          self.welcome_if_new(node)
          return result
docs: If we get a response, add the node to the routing table.  If
          we get no response, make sure it's removed from the routing table.