code: func (s *Simulation) NodeIDs() (ids []enode.ID) {
  	nodes := s.Net.GetNodes()
  	ids = make([]enode.ID, len(nodes))
  	for i, node := range nodes {
  		ids[i] = node.ID()
  	}
  	return ids
  }
docs: // NodeIDs returns NodeIDs for all nodes in the network.