code: def retryNextHost(self, connector=None):
          
          if not self.continueTrying:
              msg = "TxMongo: Abandoning {0} on explicit request.".format(connector)
              log.msg(msg)
              return
  
          if connector is None:
              if self.connector is None:
                  raise ValueError("TxMongo: No additional connector to retry.")
              else:
                  connector = self.connector
  
          delay = False
          self.__index += 1
  
          if self.__index >= len(self.__allnodes):
              self.__index = 0
              delay = True
  
          connector.host, connector.port = self.__allnodes[self.__index]
  
          if delay:
              self.retry(connector)
          else:
              connector.connect()
docs: Have this connector connect again, to the next host in the
              configured list of hosts.