code: def test_serialize_string():
      # Make frame with string column
      df = pd.DataFrame(
          {
              "x": np.random.randint(0, 5, size=5),
              "y": np.random.normal(size=5),
          }
      )
      str_data = ["a", "bc", "def", "ghij", "klmno"]
      df["timestamp"] = str_data
      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 15 for calling a global function with example usage: test_serialize_string() without return types