code: def test_bottle_neck_graph(method):
      # This graph cannot use the full capacity between 0 and 1:
      #     (0) --5--> (1) --3--> (2)
      graph = csr_matrix([[0, 5, 0], [0, 0, 3], [0, 0, 0]])
      res = maximum_flow(graph, 0, 2, method=method)
      assert res.flow_value == 3
      expected_flow = np.array([[0, 3, 0], [-3, 0, 3], [0, -3, 0]])
      assert_array_equal(res.flow.toarray(), expected_flow)
  
imports: import numpy
  from numpy.testing import assert_array_equal
  import pytest
  from scipy.sparse import csr_matrix, csc_matrix
  from scipy.sparse.csgraph import maximum_flow
  from scipy.sparse.csgraph._flow import _add_reverse_edges, _make_edge_pointers, _make_tails
label_desc: Use image node_id 9 for calling a global function with example usage: test_bottle_neck_graph(method) without return types