code: def test_simple(self):
      random_matrix = rand(10, 100, 0.1)
      for matrix_format in (
          "coo",
          "csc",
          "csr",
          "bsr",
          "dia",
          "dok",
          "lil",
      ):
          matrix = random_matrix.asformat(matrix_format, copy=False)
          self.check_save_load(matrix)
  
file_path: catboost/contrib/python/scipy/py2/scipy/io/harwell_boeing/tests/test_hb.py
imports: from __future__ import division, print_function, absolute_import
  import sys
  import tempfile
  import numpy
  from numpy.testing import assert_equal, assert_array_almost_equal_nulp
  from scipy.sparse import coo_matrix, csc_matrix, rand
  from scipy.io import hb_read, hb_write
label_desc: Use image node_id 2 for calling the TestHBReadWrite obj's underlying member method code with example usage: obj.test_simple() without return types