code: def test_sparse_matrix_serializer(sparse_matrix_serializer):
      data = scipy.sparse.csc_matrix(np.array([[0, 0, 3], [4, 0, 0]]))
      stream = io.BytesIO(sparse_matrix_serializer.serialize(data))
      result = scipy.sparse.load_npz(stream).toarray()
      expected = data.toarray()
      assert np.array_equal(result, expected)
  
imports: from __future__ import absolute_import
  import io
  import json
  import os
  import numpy
  import pytest
  import scipy.sparse
  from sagemaker.serializers import CSVSerializer, NumpySerializer, JSONSerializer, IdentitySerializer, SparseMatrixSerializer, JSONLinesSerializer, LibSVMSerializer, DataSerializer
  from tests.unit import DATA_DIR
label_desc: Use image node_id 39 for calling a global function with example usage: test_sparse_matrix_serializer(sparse_matrix_serializer) without return types