docstr: The digon should receive the maximum amount of flow it can handle.
  Taken from ticket #749 by @chuongdo.
docstr_tok: ["The","digon","should","receive","the","maximum","amount","of","flow","it","can","handle",".","Taken","from","ticket","#","749","by","@","chuongdo","."]
code: def test_finite_capacity_neg_digon(self):
      """The digon should receive the maximum amount of flow it can handle.
      Taken from ticket #749 by @chuongdo."""
      G = nx.DiGraph()
      G.add_edge("a", "b", capacity=1, weight=-1)
      G.add_edge("b", "a", capacity=1, weight=-1)
      min_cost = -2
      assert nx.min_cost_flow_cost(G) == min_cost
  
      flowCost, H = nx.capacity_scaling(G)
      assert flowCost == -2
      assert H == {"a": {"b": 1}, "b": {"a": 1}}
      assert nx.cost_of_flow(G, H) == -2
  
imports: import bz2
  import importlib.resources
  import os
  import pickle
  import pytest
  import networkx
label_desc: Use image node_id 14 for calling the TestMinCostFlow obj's underlying member method code with example usage: obj.test_finite_capacity_neg_digon() without return types