code: def test_simple_graph():
      # This graph looks as follows:
      #     (0) --5--> (1)
      graph = csr_matrix([[0, 5], [0, 0]])
      res = maximum_flow(graph, 0, 1)
      assert res.flow_value == 5
      expected_residual = np.array([[0, 5], [-5, 0]])
      assert_array_equal(res.residual.toarray(), expected_residual)
  
file_path: catboost/contrib/python/scipy/py3/scipy/sparse/csgraph/tests/test_flow.py
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
label_desc: Use image node_id 7 for calling a global function with example usage: test_simple_graph() without return types