code: def test_categorical_coerces_datetime(all_parsers):
      parser = all_parsers
      dti = pd.DatetimeIndex(
          ["2017-01-01", "2018-01-01", "2019-01-01"], freq=None
      )
      dtype = {"b": CategoricalDtype(dti)}
  
      data = "b\n2017-01-01\n2018-01-01\n2019-01-01"
      expected = DataFrame({"b": Categorical(dtype["b"].categories)})
  
      result = parser.read_csv(StringIO(data), dtype=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 13 for calling a global function with example usage: test_categorical_coerces_datetime(all_parsers) without return types