code: def test_empty_raises(self):
      with pytest.raises(nx.NetworkXError):
          G = nx.empty_graph()
          T = nx.gomory_hu_tree(G)
  
file_path: networkx/networkx/algorithms/flow/tests/test_gomory_hu.py
imports: from itertools import combinations
  import pytest
  import networkx
  from networkx.algorithms.flow import boykov_kolmogorov, dinitz, edmonds_karp, preflow_push, shortest_augmenting_path
label_desc: Use image node_id 11 for calling the TestGomoryHuTree obj's underlying member method code with example usage: obj.test_empty_raises() without return types