code: def test_read_csv_categorical() -> None:
      f = io.BytesIO()
      f.write(
          b"col1,col2,col3,col4,col5,col6\n'foo',2,3,4,5,6\n'bar',8,9,10,11,12"
      )
      f.seek(0)
      df = pl.read_csv(
          f, has_header=True, dtypes={"col1": pl.Categorical}
      )
      assert df["col1"].dtype == pl.Categorical
  
imports: from __future__ import annotations
  import contextlib
  import io
  import operator
  from typing import TYPE_CHECKING, Any, Callable, Literal
  import pytest
  import polars
  from polars import StringCache
  from polars.exceptions import CategoricalRemappingWarning, StringCacheMismatchError
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 2 for calling a global function with example usage: test_read_csv_categorical() without return types