code: def test_directed(self):
      assert not self.G.is_directed()
      assert self.dv.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 TestToDirected obj's underlying member method code with example usage: obj.test_directed() without return types