code: def test_categorical_format():
      s = pd.Series(["a", "b", "c"]).astype("category")
      known = dd.from_pandas(s, npartitions=1)
      unknown = known.cat.as_unknown()
      exp = (
          "Dask Series Structure:\n"
          "npartitions=1\n"
          "0    category[known]\n"
          "2                ...\n"
          "dtype: category\n"
          "Dask Name: from_pandas, 1 graph layer"
      )
      assert repr(known) == exp
      exp = (
          "Dask Series Structure:\n"
          "npartitions=1\n"
          "0    category[unknown]\n"
          "2                  ...\n"
          "dtype: category\n"
          "Dask Name: from_pandas, 1 graph layer"
      )
      assert repr(unknown) == exp
  
imports: from __future__ import annotations
  from textwrap import dedent
  import numpy
  import pandas
  import pytest
  import dask.array
  import dask.dataframe
  from dask.dataframe.utils import get_string_dtype, pyarrow_strings_enabled
  from dask.utils import maybe_pluralize
label_desc: Use image node_id 12 for calling a global function with example usage: test_categorical_format() without return types