code: def test_bipartite_sets_directed(self):
      G = nx.path_graph(4)
      D = G.to_directed()
      X, Y = bipartite.sets(D)
      assert X == {0, 2}
      assert Y == {1, 3}
  
file_path: networkx/networkx/algorithms/bipartite/tests/test_basic.py
imports: import pytest
  import networkx
  from networkx.algorithms import bipartite
label_desc: Use image node_id 6 for calling the TestBipartiteBasic obj's underlying member method code with example usage: obj.test_bipartite_sets_directed() without return types