code: def testUnionWithConflict(self):
      g1 = Graph.Tree(7, 2)
      g1["name"] = "Tree"
      g2 = Graph.Lattice([7])
      g2["name"] = "Lattice"
      g = union([g1, g2])  # Issue 422
      self.assertTrue(
          sorted(g.get_edgelist())
          == [
              (0, 1),
              (0, 2),
              (0, 6),
              (1, 2),
              (1, 3),
              (1, 4),
              (2, 3),
              (2, 5),
              (2, 6),
              (3, 4),
              (4, 5),
              (5, 6),
          ]
      )
      self.assertTrue(
          sorted(g.attributes()),
          ["name_1", "name_2"],
      )
  
imports: import unittest
  from igraph import Graph, disjoint_union, intersection, union
label_desc: Use image node_id 9 for calling the OperatorTests obj's underlying member method code with example usage: obj.testUnionWithConflict() without return types