code: def testUnicodeAttributeNameCombination(self):
      g = Graph.Erdos_Renyi(n=9, m=20)
      g.es["test"] = 1
      g.contract_vertices([0, 0, 0, 1, 1, 1, 2, 2, 2])
  
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 1 for calling the UnicodeAttributeTests obj's underlying member method code with example usage: obj.testUnicodeAttributeNameCombination() without return types