docstr: Tests that the unique dominating set for the null graph is an empty set
docstr_tok: ["Tests","that","the","unique","dominating","set","for","the","null","graph","is","an","empty","set"]
code: def test_null_graph(self):
      """Tests that the unique dominating set for the null graph is an empty set"""
      G = nx.Graph()
      assert min_weighted_dominating_set(G) == set()
  
file_path: networkx/networkx/algorithms/approximation/tests/test_dominating_set.py
imports: import pytest
  import networkx
  from networkx.algorithms.approximation import min_edge_dominating_set, min_weighted_dominating_set
label_desc: Use image node_id 3 for calling the TestMinWeightDominatingSet obj's underlying member method code with example usage: obj.test_null_graph() without return types