code: def test_directed(self):
      assert self.DG.is_directed()
      assert not self.uv.is_directed()
  
imports: import pytest
  import networkx
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 2 for calling the TestToUndirected obj's underlying member method code with example usage: obj.test_directed() without return types