code: def test_subgraph_edgesubgraph_toundirected(self):
      G = self.G.copy()
      SG = G.subgraph([4, 5, 6])
      SSG = SG.edge_subgraph([(4, 5), (5, 4)])
      USSG = SSG.to_undirected()
      assert list(USSG) == [4, 5]
      assert sorted(USSG.edges) == [(4, 5)]
  
imports: import pytest
  import networkx
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 10 for calling the TestChainsOfViews obj's underlying member method code with example usage: obj.test_subgraph_edgesubgraph_toundirected() without return types