code: def test_nonzero_net_demand_raise(simple_flow_graph):
      G = simple_flow_graph
      nx.set_node_attributes(G, {"b": {"demand": -4}})
      pytest.raises(nx.NetworkXUnfeasible, nx.network_simplex, G)
  
imports: import bz2
  import importlib.resources
  import os
  import pickle
  import pytest
  import networkx
label_desc: Use image node_id 7 for calling a global function with example usage: test_nonzero_net_demand_raise(simple_flow_graph) without return types