code: def test_pickle_dataframe_categorical():
      np.random.seed(0)
  
      df = DataFrame()
      df["keys"] = pd.Categorical(
          ["a", "a", "a", "b", "a", "b", "a", "b", "a", "c"]
      )
      df["vals"] = np.random.random(len(df))
  
      check_serialization(df)
  
file_path: cudf/python/cudf/cudf/tests/test_pickling.py
imports: import pickle
  import numpy
  import pandas
  import pytest
  from cudf import DataFrame, GenericIndex, RangeIndex, Series
  from cudf.core.buffer import as_buffer
  from cudf.testing._utils import assert_eq
label_desc: Use image node_id 4 for calling a global function with example usage: test_pickle_dataframe_categorical() without return types