code: def test_lsqr(matrices):
      A_dense, A_sparse, b = matrices
      res0 = splin.lsqr(A_dense, b)
      res = splin.lsqr(A_sparse, b)
      assert_allclose(res[0], res0[0], atol=1e-5)
  
imports: import pytest
  import numpy
  import scipy.sparse
  import scipy.sparse.linalg
  from numpy.testing import assert_allclose
label_desc: Use image node_id 7 for calling a global function with example usage: test_lsqr(matrices) without return types