code: def testCombinationConcat(self):
      g = self.g
      g.es["name"] = list("ABCDEFG")
      g.simplify(combine_edges={"name": "concat"})
      self.assertFalse("weight" in g.edge_attributes())
      self.assertFalse("weight2" in g.edge_attributes())
      self.assertTrue(g.es["name"] == ["AB", "C", "DEF"])
  
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 11 for calling the AttributeCombinationTests obj's underlying member method code with example usage: obj.testCombinationConcat() without return types