code: def restart(self, timeout=300, config_callback=None):
          
          for member_id in self.server_map:
              host = self.server_map[member_id]
              server_id = self._servers.host_to_server_id(host)
              server = self._servers._storage[server_id]
              server.restart(timeout, config_callback)
          self.waiting_member_state()
docs: Restart each member of the replica set.