code: def test_multidigraph():
      """Multidigraphs are acceptable."""
      G = nx.MultiDiGraph()
      G.add_weighted_edges_from(
          [(1, 2, 1), (2, 3, 2)], weight="capacity"
      )
      flowCost, H = nx.network_simplex(G)
      assert flowCost == 0
      assert H == {1: {2: {0: 0}}, 2: {3: {0: 0}}, 3: {}}
  
imports: import bz2
  import importlib.resources
  import os
  import pickle
  import pytest
  import networkx
label_desc: Use image node_id 22 for calling a global function with example usage: test_multidigraph() without return types