code: def test_linear_sum_assignment_trivial_cost(num_rows, num_cols):
      C = np.empty(shape=(num_cols, num_rows))
      row_ind, col_ind = linear_sum_assignment(C)
      assert len(row_ind) == 0
      assert len(col_ind) == 0
  
file_path: scipy/scipy/optimize/tests/test_linear_assignment.py
imports: from numpy.testing import assert_array_equal
  import pytest
  import numpy
  from scipy.optimize import linear_sum_assignment
  from scipy.sparse import random
  from scipy.sparse._sputils import matrix
  from scipy.sparse.csgraph import min_weight_full_bipartite_matching
  from scipy.sparse.csgraph.tests.test_matching import linear_sum_assignment_assertions, linear_sum_assignment_test_cases
label_desc: Use image node_id 9 for calling a global function with example usage: test_linear_sum_assignment_trivial_cost(num_rows, num_cols) without return types