code: def testCombinationProd(self):
      g = self.g
      g.simplify(combine_edges="prod")
      self.assertTrue(g.es["weight"] == [2, 3, 120])
      self.assertTrue(g.es["weight2"] == [2, 3, 120])
  
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 8 for calling the AttributeCombinationTests obj's underlying member method code with example usage: obj.testCombinationProd() without return types