code: def test_serialize_masked_series():
      nelem = 50
      data = np.random.random(nelem)
      mask = utils.random_bitmask(nelem)
      bitmask = utils.expand_bits_to_bytes(mask)[:nelem]
      null_count = utils.count_zero(bitmask)
      assert null_count >= 0
      sr = cudf.Series.from_masked_array(
          data, mask, null_count=null_count
      )
      outsr = cudf.Series.deserialize(*sr.serialize())
      assert_eq(sr, outsr)
  
imports: import pickle
  import msgpack
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf.testing import _utils
  from cudf.testing._utils import assert_eq
label_desc: Use image node_id 9 for calling a global function with example usage: test_serialize_masked_series() without return types