code: def test_categorical_unique(num_elements):
      # create categorical series
      np.random.seed(12)
      pd_cat = pd.Categorical(
          pd.Series(
              np.random.choice(
                  list(string.ascii_letters + string.digits),
                  num_elements,
              ),
              dtype="category",
          )
      )
  
      # gdf
      gdf = cudf.DataFrame()
      gdf["a"] = cudf.Series.from_categorical(pd_cat)
      gdf_unique_sorted = np.sort(gdf["a"].unique().to_pandas())
  
      # pandas
      pdf = pd.DataFrame()
      pdf["a"] = pd_cat
      pdf_unique_sorted = np.sort(pdf["a"].unique())
  
      # verify
      np.testing.assert_array_equal(
          pdf_unique_sorted, gdf_unique_sorted
      )
  
imports: import operator
  import string
  import warnings
  from contextlib import contextmanager
  from textwrap import dedent
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf.core._compat import PANDAS_GE_134
  from cudf.testing._utils import NUMERIC_TYPES, assert_eq, assert_exceptions_equal, expect_warning_if
label_desc: Use image node_id 14 for calling a global function with example usage: test_categorical_unique(num_elements) without return types