code: def _cut_hypernodes(hypergraph):
      
      nodes_ = cut_nodes(hypergraph.graph)
      nodes = []
      
      for each in nodes_:
          if (each[1] == 'n'):
              nodes.append(each[0])
      
      return nodes
docs: Return the cut-nodes of the given hypergraph.
      
      @type  hypergraph: hypergraph
      @param hypergraph: Hypergraph
      
      @rtype:  list
      @return: List of cut-nodes.