code: def constructLadderGraph(self, directed=False):
      el = list(zip(list(range(0, 5)), list(range(1, 6))))
      el += list(zip(list(range(6, 11)), list(range(7, 12))))
      el += list(zip(list(range(0, 6)), list(range(6, 12))))
      g = Graph(el, directed=directed)
      return g
  
imports: import unittest
  from igraph import Cut, Graph, EdgeSeq, InternalError
  from itertools import combinations
  from random import randint
label_desc: Use image node_id 2 for calling the CutTests obj's underlying member method code with example usage: obj.constructLadderGraph(directed) and returns: g