code: def test_hstack(self):
      A = coo_matrix([[1, 2], [3, 4]])
      B = coo_matrix([[5], [6]])
  
      expected = matrix([[1, 2, 5], [3, 4, 6]])
      assert_equal(construct.hstack([A, B]).todense(), expected)
      assert_equal(
          construct.hstack([A, B], dtype=np.float32).dtype, np.float32
      )
      assert_equal(
          construct.hstack([A.tocsc(), B.tocsc()]).todense(), expected
      )
      assert_equal(
          construct.hstack(
              [A.tocsc(), B.tocsc()], dtype=np.float32
          ).dtype,
          np.float32,
      )
  
imports: import numpy
  from numpy import array
  from numpy.testing import assert_equal, assert_, assert_array_equal, assert_array_almost_equal_nulp
  import pytest
  from pytest import raises
  from scipy._lib._testutils import check_free_memory
  from scipy._lib._util import check_random_state
  from scipy.sparse import csr_matrix, coo_matrix, construct
  from scipy.sparse.construct import rand
  from scipy.sparse.sputils import matrix
label_desc: Use image node_id 17 for calling the TestConstructUtils obj's underlying member method code with example usage: obj.test_hstack() without return types