code: def test_example_from_clrs_chapter_26_1(method):
      # See page 659 in CLRS second edition, but note that the maximum flow
      # we find is slightly different than the one in CLRS; we push a flow of
      # 12 to v_1 instead of v_2.
      graph = csr_matrix(
          [
              [0, 16, 13, 0, 0, 0],
              [0, 0, 10, 12, 0, 0],
              [0, 4, 0, 0, 14, 0],
              [0, 0, 9, 0, 0, 20],
              [0, 0, 0, 7, 0, 4],
              [0, 0, 0, 0, 0, 0],
          ]
      )
      res = maximum_flow(graph, 0, 5, method=method)
      assert res.flow_value == 23
      expected_flow = np.array(
          [
              [0, 12, 11, 0, 0, 0],
              [-12, 0, 0, 12, 0, 0],
              [-11, 0, 0, 0, 11, 0],
              [0, -12, 0, 0, -7, 19],
              [0, 0, -11, 7, 0, 4],
              [0, 0, 0, -19, -4, 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 11 for calling a global function with example usage: test_example_from_clrs_chapter_26_1(method) without return types