code: def testCombinationRandom(self):
      g = self.g
      g.simplify(combine_edges="random")
      del g.es["weight2"]
      for _i in range(100):
          self.assertTrue(g.es[0]["weight"] in (1, 2))
          self.assertTrue(g.es[1]["weight"] == 3)
          self.assertTrue(g.es[2]["weight"] in (4, 5, 6))
  
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 4 for calling the AttributeCombinationTests obj's underlying member method code with example usage: obj.testCombinationRandom() without return types