code: def test_categorical_categories():
      df = DataFrame(
          {"a": ["a", "b", "c", "d", "e", "e", "a", "d"], "b": range(8)}
      )
      df["a"] = df["a"].astype("category")
      pdf = df.to_pandas(nullable=False)
  
      ddf = dgd.from_cudf(df, 2)
      dpdf = dd.from_pandas(pdf, 2)
  
      dd.assert_eq(
          ddf.a.cat.categories.to_series().to_pandas(nullable=False),
          dpdf.a.cat.categories.to_series(),
          check_index=False,
      )
  
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_series_equal
  from dask import dataframe
  from cudf import DataFrame, Series, date_range
  from cudf.testing._utils import assert_eq, does_not_raise
  import dask_cudf
label_desc: Use image node_id 17 for calling a global function with example usage: test_categorical_categories() without return types