code: def test_serialize_datetime():
      # Make frame with datetime column
      df = pd.DataFrame(
          {
              "x": np.random.randint(0, 5, size=20),
              "y": np.random.normal(size=20),
          }
      )
      ts = np.arange(0, len(df), dtype=np.dtype("datetime64[ms]"))
      df["timestamp"] = ts
      gdf = cudf.DataFrame.from_pandas(df)
      # (De)serialize roundtrip
      recreated = cudf.DataFrame.deserialize(*gdf.serialize())
      # Check
      assert_eq(recreated, df)
  
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 14 for calling a global function with example usage: test_serialize_datetime() without return types