code: def test_return_type_known_categories():
      df = pd.DataFrame({"A": ["a", "b", "c"]})
      df["A"] = df["A"].astype("category")
      dask_df = dd.from_pandas(df, 2)
      ret_type = dask_df.A.cat.as_known()
      assert isinstance(ret_type, dd.Series)
  
imports: from __future__ import annotations
  import contextlib
  import operator
  import warnings
  import numpy
  import pandas
  import pytest
  import dask
  import dask.dataframe
  from dask.dataframe import _compat
  from dask.dataframe._compat import PANDAS_GE_150, PANDAS_GE_200, PANDAS_GE_210, tm
  from dask.dataframe._pyarrow import to_pyarrow_string
  from dask.dataframe.core import _concat
  from dask.dataframe.utils import assert_eq, clear_known_categories, get_string_dtype, make_meta, pyarrow_strings_enabled
label_desc: Use image node_id 13 for calling a global function with example usage: test_return_type_known_categories() without return types