code: def add_nodes(self, nodes):
          '''The format of node is similar to add_node.
          If node contains a key 'cluster_node'
          whose value is an instance of ClusterNode,
          it will be used directly.
          '''
          new_nodes, master_map = self._add_nodes_as_master(nodes)
  
          for n in new_nodes:
              if n.name not in master_map:
                  continue
              master_name = master_map[n.name]
              target = self.get_node(master_name)
              if not target:
                  raise NodeNotFound(master_name)
              n.replicate(target.name)
              n.flush_cache()
              target.flush_cache(f add_nodes(self, nodes):
          '''The format of node is similar to add_node.
          If node contains a key 'cluster_node'
          whose value is an instance of ClusterNode,
          it will be used directly.
          '''
          new_nodes, master_map = self._add_nodes_as_master(nodes)
  
          for n in new_nodes:
              if n.name not in master_map:
                  continue
              master_name = master_map[n.name]
              target = self.get_node(master_name)
              if not target:
                  raise NodeNotFound(master_name)
              n.replicate(target.name)
              n.flush_cache()
              target.flush_cache()
docs: The format of node is similar to add_node.
          If node contains a key 'cluster_node'
          whose value is an instance of ClusterNode,
          it will be used directly.