code: def test_already_directed(self):
      uu = nx.to_undirected(self.uv)
      Muu = nx.to_undirected(self.Muv)
      assert edges_equal(uu.edges, self.uv.edges)
      assert edges_equal(Muu.edges, self.Muv.edges)
  
imports: import pytest
  import networkx
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 3 for calling the TestToUndirected obj's underlying member method code with example usage: obj.test_already_directed() without return types