code: def _range_matrix(a, b):
      mat = np.zeros((a, b))
      for i in range(b):
          mat[:, i] = np.arange(a)
      return mat
  
imports: import pytest
  import numpy
  from scipy.optimize import quadratic_assignment, OptimizeWarning
  from scipy.optimize._qap import _calc_score
  from numpy.testing import assert_equal, assert_, assert_warns
label_desc: Use image node_id 2 for calling a global function with example usage: _range_matrix(a, b) and returns: mat