code: def test_categorical_category_dtype_unsorted(all_parsers):
      parser = all_parsers
      data = """a,b
  1,a
  1,b
  1,b
  2,c"""
      dtype = CategoricalDtype(["c", "b", "a"])
      expected = DataFrame(
          {
              "a": [1, 1, 1, 2],
              "b": Categorical(
                  ["a", "b", "b", "c"], categories=["c", "b", "a"]
              ),
          }
      )
  
      result = parser.read_csv(StringIO(data), dtype={"b": dtype})
      tm.assert_frame_equal(result, 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 11 for calling a global function with example usage: test_categorical_category_dtype_unsorted(all_parsers) without return types