code: def test_categorical_dtype_single(all_parsers, dtype, request):
      # see gh-10153
      parser = all_parsers
      data = """a,b,c
  1,a,3.4
  1,a,3.4
  2,b,4.5"""
      expected = DataFrame(
          {
              "a": [1, 1, 2],
              "b": Categorical(["a", "a", "b"]),
              "c": [3.4, 3.4, 4.5],
          }
      )
      if parser.engine == "pyarrow":
          mark = pytest.mark.xfail(
              strict=False,
              reason="Flaky test sometimes gives object dtype instead of Categorical",
          )
          request.applymarker(mark)
  
      actual = parser.read_csv(StringIO(data), dtype=dtype)
      tm.assert_frame_equal(actual, expected)
  
imports: from io import StringIO
  import os
  import numpy
  import pytest
  from pandas._libs import parsers
  from pandas.core.dtypes.dtypes import CategoricalDtype
  import pandas
  from pandas import Categorical, DataFrame, Timestamp
  import pandas._testing
label_desc: Use image node_id 2 for calling a global function with example usage: test_categorical_dtype_single(all_parsers, dtype, request) without return types